[CUTTING ROOM FLOOR] 3809/2801: M6800 EXORcises to 6502 Indirection

Scraps from the cutting room floor,
from around M6800 EXORcises to 6502 Indexing

This is the author's record of some of the stuff that got discarded; 
taken out of order, 
it does not tell things hidden things that happened,
or indicate directions the plot will take, etc. 

More than what is here,
you should want to read the story,
which begins here:  
https://joelrees-novels.blogspot.com/2025/09/3809-2801-tale-of-mcus-and-time-part-1-2801.html

2801
Terms of Engagement
Cutting Room Floor

M6800 EXORcises

TOC

"We've been asked to be careful about using students' actual addresses and phone numbers in class, so I'll mark them out." He did so and put the letter on the opaque projector. 

He commented on my letter and asked the class for comments and questions, and then he handed it back to me. "Looks good to send it like this. I hope you don't mind a little extra practice typing it again."

"No problem. I already sent it last night."

"Oh." He raised his eyebrows. 

He turned to the class and said, "I don't see anything on Cyndy's letter to comment on, so I'm not going to ask her to let me mark hers up." He handed it back to her. "I think you can send it like this."

"Anyone else with a letter of inquiry that you want comments on?"

Hec handed his to him, and he scanned over it. "Cyndy typed this up?"

"Yeah."

"Do you mind if I mark out the address, Cyndy?"

"Sure. It's okay."

After discussing some points on Hec's letter, he handed it back. "Sorry about marking it up, Cyndy."

"No problem."

Rick and several other students gave him hand-written letters to look over, and he offered pointers and handed them back. 

 

*******

"True. Anyway, once you understand how these two modes work here, I think you'll be able to think of more ways to use them." 

 He paused again, to let us think, before continuing. "Now there's one more mode, and I want to mention it. It's a mode only for jumps, that they call absolute indirect in the docs. An absolute jump moves program flow to the 16-bit address that the instruction specifies. An absolute indirect jump moves program flow to the 16-bit address that is stored at the address specified in the instruction."

 

********** 

"So, Joe, do you have yours with you?" he asked as he turned the opaque projector on.

Cyndy gave me a querying look, and responded before I could. "I have mine typed up." She slipped it out of her notebook and handed it to Mr. Mori while I got my copy from the typing class out.

He looked puzzled, and accepted Cyndy's, but turned to me. I handed him my typed copy of my earlier draft. 

Rick glanced over at me. "You kept a copy, then. Smart move." 

Mr. Mori looked them both over, then said, "It looks like you both did a bit more editing before typing these up yesterday."

"Ms. Wilson made some suggestions," Cyndy explained before I could.

"Nice of her."

Cyndy was still querying me with her eyes. 

"We've been asked to be careful about showing students' actual addresses and phone numbers in class, do you mind if I mark out your address and phone number and show this to the class?"

"No problem, either way," I replied. "But, for the record, that's not what I actually sent."

"Sent?" Mr. Mori gave me a quick look.

"I guess I got impatient last night." 

He blinked at me. "You have a typewriter at home?"

"Handwritten. I was careful to make it legible."

"I guess you didn't make a copy of that?"

"Penciled, with mark-up." I turned to dig into my notes for the scratchwork, but Cyndy was holding a piece of paper up for me.

It was my turn to to give her a querying look.

"You might want this," she said, quietly, with a knowing smile.

I blinked and accepted it. 

It was my own writing, the letter I thought I had sent the night before. 

"What? How on earth?"

Cyndy smirked and kept her voice low enough only Hec and Rick and I could hear. "She said you didn't notice."

I gave an embarrassed laugh and covered my eyes with it for a moment before handing it over to Mr. Mori without comment. 

"Well, good for you, you made a copy. Does not look like pencil, though."

I coughed. "I'm going to have to blame this one on my study partner."

"Good for you, Cyndy, although you might have gone so far as to encourage him to be more patient."

"Hec and I studied at my house last night." 

"Rick?"

"Different study partner," Rick said. 

Mr. Mori gave the four of us a look and said, "Curiouser and curiouser."

None of us volunteered more information.

He chuckled. "Well, let's take a look. I'll go ahead and mark out your address and phone number." 

******* Need to talk about coordinating queries 

"So we should never give it an address that ends in hexadecimal $FF, then," Mark said. He wrote in a note next to address 2101, "Don't use JMP ($XXFF). No 255 in low byte.".  And he put the marker back and sat down.

"Correct."

Mr. Mori shut the overhead projector off, leaving it in place to cool.

"We've been burning the brain oil, so let's shift gears and look at your letters of inquiry." He moved an opaque projector in beside the transparency overhead projector.

"So, Joe, did you bring a copy of your letter?" he asked as he turned the opaque projector on.

Cyndy gave me a querying look, and responded before I could. "I have mine typed up." She slipped it out of her notebook and handed it to Mr. Mori while I got my copy from the typing class out.

He looked puzzled, and accepted Cyndy's, but turned to me. I handed him my copy. 

He looked them both over, then said to me, "Do you mind if I mark out your address and phone number and show this to the class?"

"No problem, either way," I replied.

"We've been asked to be careful about using students' actual addresses and phone numbers in class, so I'll mark them out." He did so and put the letter on the opaque projector. 

"It looks like you did a bit more editing before typing this up."

"Ms. Wilson gave me some pointers."

"Good of her."

He commented on my letter and asked the class for comments and questions, and then he handed it back to me. "Looks good to send it like this. I hope you don't mind a little extra practice typing it again."

"No problem. I already sent it last night."

"Oh." He raised his eyebrows. 

He turned to the class and said, "I don't see anything on Cyndy's letter to comment on, so I'm not going to ask her to let me mark hers up." He handed it back to her. "I think you can send it like this."

"Anyone else with a letter of inquiry that you want comments on?"

Hec handed his to him, and he scanned over it. "Cyndy typed this up?"

"Yeah."

"Do you mind if I mark out the address, Cyndy?"

"Sure. It's okay."

After discussing some points on Hec's letter, he handed it back. "Sorry about marking it up, Cyndy."

"No problem."

Rick and several other students gave him hand-written letters to look over, and he offered pointers and handed them back. 

****

 

"I've arranged with Ms. Wilson to make typewriters available in the typing lab after school. They have correcting ribbon, so you don't have to type perfectly. But if you're confident you can use handwriting that doesn't cause the secretary and managers that will be reading your letters eyestrain, you can write them by hand, too. Just," he gave me another look. "Let me check them before you send them. And make a copy for me to refer to in case the companies you contact contact the school. And keep another copy for yourself."

 

FTR, from the reality chapter: "I pulled out my query letter and looked it over, and decided to add a few things to it, mentioning the other processors we were studying, and making my interest in the prototyping kit pricing explicit. I wrote it out by hand in pencil, erasing and rewriting until I thought my additions were clear enough, then hand-copied it with a pen."  

 

 

(Besides, it's a little hard to remember all of what happened so long ago.) 

 

 

 

 

 

(Descendants of the 6502, by the way, are still being used in new designs as I write this.) 

*******

constant base, 16-bit array anywhere in memory, but width limited, methods exist to get around width

variable base/constant offset must start in page zero -- mention direct page is page zero

mention instruction differences, unary (RMW) not available to Y

 

8-bit constant short form exists, but wraps around, and only for X index instructions plus LD/STX ,Y indexed  

 

indexed indirect for table of indexes in page zero (index half bytes wrap in page zero), X points to index in page zero

 

indirect indexed is for base address in page zero (base halves wrap), Y has offset

 

Mark said, "So the 6502 is carrying the concept of page zero as a bank of pseudo-registers a bit farther than the 6800."

"Thank you for pointing that out," replied Mr. Mori. "Once you understand how these two modes work here, I think you'll be able to think of more ways to use them."

We spent some time discussing indirection and byte order, letting the students who hadn't quite kept up catch up. I'm sure you've kept up okay, so I'm going to skip all of that. 

(Besides, it's a little hard to remember all of what happened so long ago.) 

 

 

is basically loading an immediate 16-bit value into the program counter. An absolute indirect jump, then, is loading the program counter from the 16-bit address specified in the instruction.

"If you hand-write the final copy to send in, write neatly enough that the secretary that reads it doesn't have to strain her eyes. I've arranged with Ms. Wilson to let those of you who want to try typing your own borrow typewriters with correcting ribbons in the typing class, if you want to do it that way. Either way, keep a copy before you send it, so we can refer to it. 

(Descendants of the 6502, by the way, are still being used in new designs as I write this.) 

 

*******

"Something like this?"

Pete said, "So I guessed right?" 

"I guess you did. What else is different about it, say, from the 6800 and 9900?"

"Little endian," Harvey said.

"Yep. The 6502 puts its low byte first, like the 8080 and the 1802." 

Bill asked, "Are X and Y interchangeable?"

******

"Okay, Harvey, you said the 6502 has two index registers, but they are only eight bits wide, right?"

"I think so." 

"And, Pete, you mentioned a 16-bit index constant part for the instruction."

"I thought it might be a possibility."

"What benefit would it have?" 

"When you know an array's address, it could start anyplace in memory. But the index register would limit its width." 

"Mr. Mori put a transparency on the projector.

 

"And there you are. Remember that the 6502 puts its low byte first."

"Little endian," Harvey said.

"Yep. There are some differences about which instructions can be used with Y indexed addressing and with X indexed addressing. You might not know what I mean if I say X indexed is provided for both unary and binary instructions and Y indexed provided for binary. But file that fact away for now." 

Ted raised his hand. "Unary instructions are read-modify-write instructions, right?"

"You're trying to confuse everyone."

"Sorry."

Mr. Mori grinned. "Just kidding. You're right and we'll talk about that later. "

He paused. "Can you think of a way of getting around the width limitation?" 

I suggested, "Use the middle of the array for the constant base address?" 

Mr. Mori nodded. "Can you tell us how to do that?"

While I was thinking, Frank raised his hand.

"Frank?"

"If the array is larger than 256 bytes but smaller than 513, provide one routine to point into the low half and another to point into the high half, and figure out somehow which half you're needing to point to choose which routine to use."

"Very good, and we'll talk about how to actually do that later, as well. There's another way that involves modify the constant base in code at run-time, but I do not want to teach you that."

"Why not?" Karl asked.

Cyndy said, "You might modify the wrong part of the instruction?"

"There's that. What else?"

Frank said, "You might modify the constant part of the instruction once, and something might interrupt the code so that it fails to restore it before the next time you try to access the array." 

"Excellent. And the guys who designed the 6502 knew that could happen, so they gave us another way, which we aren't quite ready to talk about yet." 

He swapped transparencies. "Just to be complete, what does our 16-bit constant offset and 8-bit variable base address mean for arrays when you don't know where they begin until the program runs?" 

 

 

After some consulting with each other and with the class, they came up with this: 

Once you see this, you may be able to think of other ways to use these two modes, but I think this is basically what they were thinking of when they chose the modes to support."

 

 

 

****** 

Rick said, "I think I should be, as well."

"Okay, okay." I stood up and  

"And if the constant offset from the instruction stream is only eight bits?"

"Then all arrays have to start in page zero and be less than 256 bytes in size?"

"It gets even stranger than that with some instructions." 

"Yeah. Let's talk about that." 

***** 

"Okay, Harvey, what's peculiar about the 6502?"

"It has two indexes, but they are both 8 bits wide?"

"That's one thing." 

"If the constant base address can be sixteen bits wide, we have the opposite problem from the 6800."

"How so?"

"A sixteen-bit constant base can put the array anywhere, and we'd be okay as long as the offset is less than 256. But that only works when we know where it is in advance."

"That's true. The 6502 provides this mode, and I understand that we can do with both X and Y. Would you be willing to diagram it for us?"

Harvey hesitated. "I guess I can give it a try." He approached the white board.

 

*** 

 

 

"Joe left the steps to add the two bytes out of the diagram. Is that confusing to anyone?"

Several of the guys raised their hands.

"Okay, Joe, do you mind if I take over for a bit?"

"Sure. I mean, no problem."

"Okay, we're going to role play the computer." Mr. Mori grinned and paused for effect before continuing. "When I call you, stand up. Joe, you and Rick remain standing. Scott, you're direct page memory location X16. But we need an actual address. Rick, what's the actual address?"

"I don't know. Ten, maybe?"

"Ten it is. Barry, you're location X16 plus one. What's your address?"

"Uh, eleven?"

"Okay, Bob, you're accumulator B. What do you have when the code starts here?"

"Four."

"Right. Karl, you're the index register, X. What have you got?" 

"N."

"We need a concrete value for N so Barry and Scott know what hits them." 

"Anything less that 65,536?"

"What do you say, Joe?"

"I have the impression that addresses above 32,767 get used for stuff, so maybe below that."

"How about 31,999?"

I shrugged "I think it would be okay, but we have to divide that into high byte and low byte."

Karl looked at Barry with a grin. "You do the math."

"Well, 32,000 divided by 256," He looked at Mr. Mori, who nodded. "Is a hundred twenty-five, so the high byte is 124."

Scott nodded. "And the low byte is 255."

"Okay. But you don't have those yet. What do you have?"

Barry said, "Something random?"

"Probably."

"Okay, I have seventeen."

Scott said, "I'll have a hundred seventeen." 

Mr. Mori said, "Now we need someone to be the carry flag. Mark?" 

"Okay. I'm random to start, too?"

"Yeah."

"No carry, then." 

"Okay, Joe, read the instructions."

"Store X at location ten."

Karl said, "Scott first?"

"Yeah."

"Scott gets one twenty-four." 

Scott said, "124."

"Barry gets two fifty-five."

Barry said, "255."

I said, "Now, add B from location eleven."

Barry said, "255."

Bob said,  "Four and two fifty five makes --" he stopped. "I can't hold anything bigger than 255, so it wraps around to three, with a carry, I guess?"

Mark said, "Carry." 

I continued, "Store B to location eleven." 

Bob said, "Three."

Barry said, "Three."

Mark said, "Carry unaffected?"

I said, "Right. Now load B from location ten."

Scott said, "One twenty-four."

Bob said, "One twenty-four."

Mark said, "Carry unaffected, still?"

I said, "Right. Add constant zero to B with carry."

Mark said, "Carry."

Bob said, "One twenty-four plus one is one twenty-five."

Mark said, "No carry."

I said, "Store B in location ten."

Bob said, "One twenty-five."

Scott said, "One twenty-five."

Mark said, "Carry unaffected, no carry."

I said, "Load X from location ten."

Scott said, "124."

Barry said, "3."

Karl said, "Man this gets boring."

Mr. Mori said, "It's a good thing CPUs don't get bored, isn't it?"

We all laughed.

Karl grinned. "Well, anyway, X is now 32,003." 

I said, "And we are finally ready to do whatever op-code C was, but it's in indexed mode, and the index byte is zero."

"Yay," Karl said, and we all laughed.

Mr. Mori commented, "I don't see a return instruction."

"Is that what makes code reusable?" Rick asked.

"If your code is constructed correctly," Mr. Mori replied.

"We haven't got that far yet," I apologized.

"That's okay. We'll get there. But this prepares us to talk about the 6502."

Rick asked, "Can we all sit down, then?"

"Sure." 

We all laughed and those of us standing sat down.

 

 

But what if we don't know the base address ahead of time?"

"You're going to tell us about it?"

"Give me a hand drawing this.  

 

 

 

 

 

************* 

Draw a picture of string with constant offset, 

then array in direct page with variable offset, 

then adding the offset to an index variable in memory

6502: 

introduce absolute index on X and Y, instruction limits, and direct page index on X, instruction limits and Y for LD/ST;

Motivate the 16-bit base address problem, introduce simple memory indirect and instructions that use it.

indirect indexed ([base,X] or [offset,X] points to list of addresses)

indexed indirect ([base],Y points to the operand  

absolute indirect jump only

 

***********************

 

 

I found the right section in the stacks just as a library assistant brought Rick over.

"IBM 370," I announced quietly.

"Mainframe," Rick replied, also quietly. He read a spine. "PDP-11." He reached for the DEC manual.

"I think that's a minicomputer."

"So not a microcomputer." His hand paused.

"Mmm." I nodded.

 

Sapphire waiting in classroom? Karl or somebody joking about Joey? Hold it off?

Chapter five, section one dot two, eh, page five dash twelve."

 

"We're going to have to see if we can meet you guys there, then. You think, Cyndy?" 

"Yeah, I think so."

"I get to come along?" Sapphire asserted.

"Saturday?" I suggested. 

 

"Addressing modes, instruction set, pointer operations, branch and jump, looks like it repeats a lot of the information in the Programming manual. Hmm." 

Rick's eyes met mine, but he didn't say anything. He looked back down and continued flipping through the pages. 

I looked back down and continued. "Addition and subtraction routines, multiplication and division, counting." 

I opened to section two and read without a lot of comprehension. 

"Alpha, beta, gamma. Well, I suppose, if it's a small number and fits in an accumulator, adding requires loading the number to be added to, adding the number to add to it, and storing the result."

I moved past the table of contents

 

"Hmm. This looks like an electronic cash register," I muttered as I flipped through the pages of the manual I had. "Instructions on how to use Motorola parts to put together a point-of-sale terminal, including the programs. Complete with bar code reader." 

Rick put the Programming manual down and shifted his chair so he could read over my shoulder. 

 

I kept flipping pages and got part way through chapter 7, and stopped to look at the image at the beginning of section 2, which appeared to be a non-descript box of electronics with very few controls -- only a keylock between a couple of what appeared to be pushbuttons, with three indicator lamps or LEDs above those, on the right side of a front bevel swept back towards the top, with an exaggerated lip along the bottom edge. A large, black, blank faceplate covered an an inset open area to the right of the buttons, extending across maybe three quarters of the front panel.

"EXORciser?" Rick read the section title out loud, and hummed the signature opening phrase from Mike Oldfield's "Tubular Bells".

"For getting the demons out of our designs?" 

We both laughed. 

"Somebody at Motorola must have a sense of humor." He shook his head. "Looks kind of like a squashed toaster oven." 

"No blinking lights?" I turned the page. "Seventeen inches wide, nineteen deep, seven high. Forty-five pounds." I turned the page back.

"The Altair 8800 looks a lot more interesting, with the switches and lights on the front panel."

"I wonder if we could put that kind of front panel on this."  

"I wonder how much it costs, and what you can do with it."

 

 

Which we did when we arrived at the library. 

The librarian took us to the section where the microprocessor books were.

"These are reference works, so we can't let you check them out," she advised us, pointing out the sign of the shelves that said the same thing.

"Thanks." 

 

"Hmm, Intel 8080. IBM 360. Fairchild F8. What's that?" Rick picked up one of the Fairchild manuals and thumbed through it.

"Here we are, Motorola M6800." I picked up one of the Motorola manuals and started thumbing through it.

"Do you need anything more?" the librarian asked.

"Do you know if you'll be getting manuals for other processors?" Rick asked.

She gave Rick a thoughtful look, and said, "Let me check." 

While she went to check, Rick looked at the F8 manual, and I looked at the Motorola manual.

"Wow." Rick muttered. "The F8 looks even more primitive than the 1802." 

We thumbed through the manuals. 

"What have we here?" I muttered. "Source code and engineering diagrams for an example cash register controller."

Rick put the F8 manual down and started looking over my shoulder. "I might be able to make some sense of that," he said.

We continued to peruse the source code for a few minutes, and the librarian returned.

"The electronics technology staff has requisitioned manuals for the, uhm, Western Design Center 6502 and a couple of Texas Instruments microprocessors," she said.

"9900?" Rick asked.

"That's the one," she answered. "Both seem to be really new products."

"That's what we understand," I responded. 

"If you give me your names and phone numbers, we can let you know when we get them."

We did so, and thanked her.

 

 

 

"Oh." Rick put his car in reverse, checked his mirrors and over his shoulder and backed out of the parking space. "I guess that explains it." 

We headed for the college.

"Maybe," he added.

"You don't believe me? You could come to Seminary, you know."

Rick laughed. "Maybe I should. Just to keep an eye on you two."

 

 

The calculus class was on the second floor of Wilkerson Hall, and we passed my dad's office on the way. But Dad was in class, so we didn't see him. 

In the calculus class, Professor White held up a loaf of pumpernickel.

"How are we going to measure the volume of this loaf of brot?" 

Rick raised his hand. "Cut it in slices and measure each slice?"

"You've been reading the text. Good for you."

One of the girls whose name I don't remember suggested, "Or he saw the sliced loaf on your desk."

"Being observant is also good." Professor White lifted the tray of sliced pumpernickel. "Now, how do we measure each slice?"

"Slice up a slice?" I suggested.

"Excellent. Now, could you draw that on the chalkboard?"

 

Professor White explained sums of infinitesimals, inviting us to thing of real-world examples, waxing excited about the elegance of correct solutions, calling correct math sexy.

After class, I suggested, "Hey, I wonder if there's any docs on microprocessors in the library."

Rick looked thoughtful. He said, "We probably do have time to check."

At the library, I headed for the card catalog. Rick asked at the checkout counter. We both ended up in the stacks about the same time.

"Please note," the librarian who helped Rick said, "that this is a reference shelf, and these books cannot be checked out." 

"Got it," I answered, and Rick nodded. 

"Hmm, Intel 8080. IBM 360. Fairchild F8. What's that?" Rick picked up one of the Fairchild manuals and thumbed through it.

"Here we are, Motorola M6800." I picked up one of the Motorola manuals and started thumbing through it.

"Do you need anything more?" the librarian asked.

"Do you know if you'll be getting manuals for other processors?" Rick asked.

She gave Rick a thoughtful look, and said, "Let me check." 

While she went to check, Rick looked at the F8 manual, and I looked at the Motorola manual.

"Wow." Rick muttered. "The F8 looks even more primitive than the 1802." 

We thumbed through the manuals. 

"What have we here?" I muttered. "Source code and engineering diagrams for an example cash register controller."

Rick put the F8 manual down and started looking over my shoulder. "I might be able to make some sense of that," he said.

We continued to peruse the source code for a few minutes, and the librarian returned.

"The electronics technology staff has requisitioned manuals for the, uhm, Western Design Center 6502 and a couple of Texas Instruments microprocessors," she said.

"9900?" Rick asked.

"That's the one," she answered. "Both seem to be really new products."

"That's what we understand," I responded. 

"If you give me your names and phone numbers, we can let you know when we get them."

We did so, and thanked her.

"Are we going to eat lunch?" Rick asked as she returned to the checkout counter.

"I guess we can look at these some more tomorrow," I answered.

We left and got in his car and headed for the Whataburger down the road.

"Onions today?" Rick joked as we pulled into the drive-in.

I chuckled. "Is that relevant?" 

But I did order onions, lettuce, tomato, pickles, and cheese, with ketchup and mayonnaise. Rick ordered a grilled chicken lunch.

We talked about math and electronics while we ate, and then headed for Permian. 

As we pulled into the east student parking lot, Rick said, "Look who's here."

Sapphire was waiting outside the south-east wing entrance. I waved, and she waved back.

"What's up?" I asked, as we approached.

She shook her head. "Just missing you."

I could feel Rick's eyes roll, even though I didn't look to check.

"I'm kind of, I don't know. You're seminary was --"

Rick filled in, "Wild? Cult-like?"

"Hey," I complained.

"Wild, yes. Cult-like, no. Just things I never knew about Moses and Abraham." 

"Maybe I should come to your Seminary to protect Sapphire," Rick suggested.

"Ah, how sweet." She gave him a moue.

"Stop. I'm melting." Rick chuckled.

The electronics classroom/lab was the easternmost room of the south wing, so we talked outside until a few minutes before the bell, and Sapphire hurried for her class.

"You know you're welcome to visit the Seminary class any time."

"I need my beauty sleep."

TOC		Next
Where it starts

Copyright 2025, 2026, Joel Matthew Rees

3809/2801: Motorola M6800 EXORcises

2801
Motorola M6800 EXORcises

Early Morning Seminary

TOC

(I'm sure I lost a lot of readers on the shift to the teen romance that never was. And I'm going to lose even more readers shifting back to technology now. At least the tech is real -- for the current chapter or so.) 

Nothing remarkable happened in either chemistry class or homeroom. After homeroom, I went to the east student parking lot to meet Rick.

When he saw me, he looked me over with a doubtful expression.

"What?" 

"Mmuhhn yeah." He just shook his head. "Let's get to OC." 

We both climbed in his car, and he started the engine. Then he looked at me again, wrinkling his nose.

"Hit me with it," I said.

"When you called me last night, were you at Sapphire's house?" 

This time it was my turn to be puzzled, while he put the car in reverse, checked his mirrors and the blind spots, and backed out of the parking space. 

"No?" I responded. 

"I'm definitely getting a whiff of something," he said, as he put the car in drive and pulled out of the parking lot. "Like recent. You're not wearing some strange cologne?"

"Oh." I tested the air around me and chuckled wryly. "Becca and Maralea invited Sapphire to Seminary, so I may have gotten a hug or two from her already today. Yeah, she was wearing perfume."

He nodded, absently.

"You don't believe me?"

"Why would she be going to your seminary?"

"Good question. I guess she likes me."

He laughed. "Well, let's hope that's what it is."

"You could come to seminary, too, you know. I might need an objective point of view."

"Any reason to get me to visit your church."

We both laughed.

"I might have to do that," he complained as we waited for a stop light. The light changed and he accelerated. "Are you're going to help me with the calculus homework today?"

"I did about half of it last night, while I was studying with Sapphire. It's dead simple stuff, just working through some basic area summations preparing to discuss integration." 

"Good. I'm glad the class only meets Monday Wednesday Friday, so we have Tuesdays and Thursdays to work on homework in the library."

"Yeah. And I'm wondering if the library has books on microprocessors."

Rick glanced at me. "We can ask. After we finish the calculus homework."

At the college library, we found a study table and set up to study.

"You're right," Rick said. "This is easy stuff." 

We both got busy.

After maybe twenty-five minutes, Rick asked, "Done?"

"Just about."

He looked across the table at my work. "Working ahead again."

"Hey. It's fun." I grinned and put down my pencil.

"Says you." He grinned back. "I'll go ask at the desk."

"I'll go check the card catalog."

Rick and the library assistant beat me to the stacks.

"Univac 1100 Series would be mainframe, wouldn't it?" Rick asked in a low voice.

The assistant nodded. "That's what I understand." 

I read the spine of a nearby volume quietly, "IBM 370."

"Mainframe," Rick replied. He read another. "PDP-11 series." He reached for the DEC manual.

"I think that's a minicomputer," I muttered.

The assistant nodded in agreement again. 

"So not a microcomputer." His hand paused. "Maybe later."

(The LSI-11 implementation of the PDP-11 did exist at the time. But it was not a single-chip microprocessor. It required four chips to function, was very expensive, and studying it would probably have taught lessons of less utility to high-school students than the microprocessors we were talking about in class would teach. It was a significantly more mature class of computer. But it would have been a dream to use. 

For the record, the T-11 single-chip implementation of the LSI-11 was still several years away.) 

I responded with a non-committal "Mmm hmm."

The library assistant pointed out a sign on the shelf I was looking at. "Just a reminder, these are reference works, and can't be checked out." 

Rick and I both nodded our acknowledgement.

"Understood," I said. 

"8080 -- Intel. Repetitious cover. RCA 1800? oh, COSMAC CDP 1802. F8? What's that?" Rick picked up a Fairchild manual.

"And these don't fit on the regular shelf." The library assistant pointed out the oversize shelf. 

"Ah, 6800," I said as I picked up the Motorola M6800 Programming Reference Manual from the shelf she had just indicated.

"Do you think you'll find everything okay?" she asked.

"Probably," Rick responded as he thumbed through the F8 manual. "For now. Thanks."

"The technology department has requisitioned manuals for a few more this semester," she volunteered. "the, uhm, Western Design Center 6502 and a couple of Texas Instruments microprocessors."

"9900?" Rick asked.

"I remember that one," she answered. "They seem to be really new products."

"They are," I confirmed. 

"If you give me your names and phone numbers, we can let you know when we get them."

We did so, and thanked her again, and she returned to the checkout counter.

Rick and I flipped through the manuals we had picked up.

"Wow." Rick muttered. "The F8 looks even more primitive than the 1802." 

He put the Fairchild manual on the returns shelf. "Maybe later."

"The explanations of the microprocessor instructions in this manual look pretty detailed." I handed him the 6800 Programming manual I had picked up.

"For me?" He gave me a lopsided grin.

"Unless you don't want it." 

He opened it up to a random page. 

I grabbed the M6800 Microprocessor Applications manual that had been next to it on the shelf. " I think I'm going to go sit down."

"Good idea." 

We went back to the study table. 

While Rick flipped randomly through the pages of the Programming manual, I opened the Applications manual to the table of contents and started scanning it, subvocalizing the sections. 

"Addressing modes, instruction set, pointer operations, branch and jump, looks like it repeats or summarizes a lot of the information in the Programming manual. Hmm. Plus the electronics side of things." 

Rick didn't say anything, just continued flipping through the pages. 

"Code examples. Addition and subtraction routines, multiplication and division, counting. Chapter two, section one point five." 

I opened to section 2-1.5 and read in a low voice to myself.

  L-D-A-A ALPHA ; Maybe, load A ALPHA?" 
  A-D-D-A BETA ; Add A BETA? 
  S-T-A-A GAMMA  ; Store A GAMMA?

I explained to myself, "I guess that means GAMMA = ALPHA + BETA, if GAMMA and ALPHA and BETA are all bytes. Load the left side, add the right side, store the result. And it looks like the same sort of thing for subtraction."

"Hang on," Rick said. "There's an appendix that has a description of the instructions. Let me see." Rick flipped pages. "L-D-A loads the contents of memory into the accumulator. And," He flipped pages back. "ADD," he read in English instead of reading each letter, "adds the contents of A-C-C-X and the contents of M and places the result in A-C-C-X. A-C-C-X means accumulator A or B?" He turned the Programming Manual so I could read the page.

"Mmmm -- immediate, direct page, indexed, and extended mode operands for each of accumulators A and B. Sounds right."

"And M is memory?"

"Apparently."

"Okay," he pulled it back and flipped pages forward. "S-T-A stores the contents of accumulator X in memory. The contents of accumulator X remain unchanged. I guess I can follow that. Not that I know what to do next."

"Add with carry?"

He flipped back a few pages. "A-D-C. Right here." 

"It's a start?"

"I hope so. Hmm." He flipped pages back and forth. 

"What?"

"I don't see any ADD to X instruction," he replied.

"Increment?"

He flipped pages. "I-N-X. increment X. Add one to X."

"Maybe it has to be done in memory and then loaded into X. Hang on, there are some tables of instructions here." I flipped back a bit. "Not this one." I flipped back a bit farther. "Accumulator and memory, ah, index register and stack pointer operations. Compare, decrement, increment, load, store, transfer between the stack and index registers. No add or subtract, so it looks like we have to add in memory and then load it. Or if it's quicker, use more than one increment or decrement instruction."

"Sounds like a lot of work."

I flipped some more pages. "I'm going to copy some of this out." And I got a sheet of loose-leaf paper out of my notebook.

"Copier over there?"

"Nah. I don't want the whole page, and the manual isn't going anywhere. And I think I might remember it better if I copy it." 

I copied the very short sequences for adding and subtracting multiple bytes while Rick went back to paging through the Programming Manual. 

After a few minutes, I said, "I think I'm going to take a guess at how to add B to X," and wrote down,

 STX X16 

Rick read, "Store X in X16. How do you know there is something called X16 that you can store X in?"

"I'm sure one of these manuals explains that." 

"You're making it up."

"For now. Uhm,"

  ADDB X16

"Mmm, how do I do this?" I flipped pages in the manual, looking at the sample code. "Oh, this would probably work."

  ADDB X16+1

"Add to accumulator B from X16 plus one," Rick read. "That would be one memory location beyond X16?"

"I think so."

"Your have B reversed from the example."

"I wonder if it matters." 

Rick give me a "Who knows?" shrug.

I continued. "If it doesn't,"

 LDAA X16
 ADCA 

Again I got stuck.

Rick suggested, "Just adding zero along with the carry might work?"

"Genius."

"Huh."

"Constant is immediate mode, and that uses the, uhm, pound sign." I continued,

 ADCA #0 
 STAB X16+1
 STAA X16 
 LDX X16

Rick read, "Load accumulator A from location X16, add carry immediate zero to A, store B at one beyond X16, store A at X16, and finally load X back in from X16."

We both stared at the code for maybe half a minute. 

"Sounds good, but I wonder if you could clear A and add A from X16 instead?"

"I wonder what would happen to the carry flag. Wait." I flipped back, looking for a table that had the load instruction in it. 

Rick flipped forward a bit.

"C-L-R clear," he said. "R stands for reset. Clears the carry flag."

"Maybe you could clear A first." I read from the table I found, "But loading the accumulator does not affect the carry flag."

"So that sounds like your sequence should work. That's a lot of work to go to every time you want to add B to X."

"There's got to be a way to avoid repeating that every time."

(There is a way to avoid repeating the code, of course, but that's for them to discover later. And what they came up with is not the most optimal, but it's pretty good first efforts. Way better than I and my friends in the reality you know could have done.) 

"I think I'm going to look at decimal adjust later," I commented to myself. "I wonder if carries are the same for decimal and binary."

Rick gave me another shrug, and I turned back to the manual and continued reading. 

"Hmm. It looks like they're saying that standard multiply by column works for binary like it works for base ten, but we knew that."

"You knew that."

"You did too."

"You told me about it once." 

I continued browsing. "Booth's algorithm? I wonder what that is." 

I turned a querying glance at Rick, and he returned a shrug.

"Maybe I'll copy this out later, too." 

I went back to the table of contents. "DMA -- direct memory access." 

"I wish I could make as much sense out of things as you do," Rick complained quietly, as he flipped pages.  

"What do you mean. You are making as much sense out of it as I am. Huh." I stopped flipping pages. "Scanning wand, UPC symbol." 

"Wand?" Rick grinned.

"Magic, I guess." 

We laughed. Quietly.

"Chapter six, design techniques. This looks like it might make a good textbook for our class. Hardware/software tradeoffs, hardware configuration, what's macro flow?"

Rick set the Programming manual down and moved around to my side of the table so he could get a better look.

I continued scanning the table of contents. "Chapter seven, development tasks." I continued silently to the bottom of the page. "Any idea what 'build virtual machine' means?"

"No idea." Rick shrugged and read the next entry, a little loudly. "The EXORciser?" He started humming the signature opening phrase of Mike Oldfield's "Tubular Bells", and we both laughed out loud.

We heard a shush from the checkout counter. I looked up and gave the library staff a thumbs-up, and the librarian who had helped us gave me a mock stern look, but with a real warning behind it.

"For getting the demons out of our designs?" I suggested, more quietly than before.

We both snickered. I glanced back to check with the librarian at the desk. She rolled her eyes. 

"Some engineer likes puns," Rick muttered. 

"Chapter seven, page sixty-nine." I flipped to the specified page. That page had an image of a rather non-descript box. The swept-back front panel with an exaggerated lower lip might have been an attempt to make it look futuristic or something. The left three-quarters was occupied by a blank inset, and the only controls were to the right of the inset -- a keyswitch between two pushbuttons, with three indicator lamps, probably LEDs, above the controls, and the EXORciser logo above that.  

Rick shook his head. "Looks kind of like a squashed toaster oven." 

"No blinkenlights?" I turned the page. "Seventeen inches wide, nineteen deep, seven high. Forty-five pounds." (43.18 cm by 48.26 cm by 17.78 cm; about 20.412 kg.)

"The Altair 8800 looks a lot more interesting, what with all the switches and lights on the front panel."

"I wonder if we could put that kind of front panel on this."  

"I wonder how much it costs, and what you can do with it."

"I don't see any indication of prices. I might have asked about that in my letter of inquiry, if I had read this first." 

"Maybe they'll send you a price list anyway. I'll bet the SWTPC will be cheaper."

"Different purposes, probably." 

"Yeah, I think we need to know more about what these gadgets do before worrying about prices." 

We scanned more of the chapter without comment until Rick looked at his watch. 

"Time to go for lunch." 

"Whataburger?" 

"Yah." 

We put the manuals on the returns shelf, thanked the library staff on our way out, and headed north in Rick's car for the Whataburger down the road.

"Onions today?" Rick joked as we pulled into the drive-in.

I chuckled. "Is that relevant?" 

But I think I did order onions, lettuce, tomato, pickles, and cheese, with ketchup and mayonnaise. I usually did. Rick probably ordered grilled chicken with mayonnaise sauce, per his usual.

We talked about math and electronics while we ate, and then headed for Permian. 

TOC		ALUs, Register Indirect Review,  Role Playing the 6800
Where it starts

Copyright 2026 Joel Matthew Rees

[Edit record here:  https://joelrees-novels.blogspot.com/2026/07/mark00-3809-2801-motorola-m6800-exorcises.html]

[MARK00] 3809/2801: Motorola M6800 EXORcises

EDIT MARK record 00
Read the current version at: 
https://joelrees-novels.blogspot.com/2026/07/3809-2801-motorola-m6800-exorcises.html

2801
Motorola M6800 EXORcises

Early Morning Seminary

TOC

(I'm sure I lost a lot of readers on the shift to the teen romance that never was. And I'm going to lose even more readers shifting back to technology now. At least the tech is real -- for the current chapter or so.) 

Nothing remarkable happened in either chemistry class or homeroom. After homeroom, I went to the east student parking lot to meet Rick.

When he saw me, he looked me over with a doubtful expression.

"What?" 

"Mmuhhn yeah." He just shook his head. "Let's get to OC." 

We both climbed in his car, and he started the engine. Then he looked at me again, wrinkling his nose.

"Hit me with it," I said.

"When you called me last night, were you at Sapphire's house?" 

This time it was my turn to be puzzled, while he put the car in reverse, checked his mirrors and the blind spots, and backed out of the parking space. 

"No?" I responded. 

"I'm definitely getting a whiff of something," he said, as he put the car in drive and pulled out of the parking lot. "Like recent. You're not wearing some strange cologne?"

"Oh." I tested the air around me and chuckled wryly. "Becca and Maralea invited Sapphire to Seminary, so I may have gotten a hug or two from her already today. Yeah, she was wearing perfume."

He nodded, absently.

"You don't believe me?"

"Why would she be going to your seminary?"

"Good question. I guess she likes me."

He laughed. "Well, let's hope that's what it is."

"You could come to seminary, too, you know. I might need an objective point of view."

"Any reason to get me to visit your church."

We both laughed.

"I might have to do that," he complained as we waited for a stop light. The light changed and he accelerated. "Are you're going to help me with the calculus homework today?"

"I did about half of it last night, while I was studying with Sapphire. It's dead simple stuff, just working through some basic area summations preparing to discuss integration." 

"Good. I'm glad the class only meets Monday Wednesday Friday, so we have Tuesdays and Thursdays to work on homework in the library."

"Yeah. And I'm wondering if the library has books on microprocessors."

Rick glanced at me. "We can ask. After we finish the calculus homework."

At the college library, we found a study table and set up to study.

"You're right," Rick said. "This is easy stuff." 

We both got busy.

After maybe twenty-five minutes, Rick asked, "Done?"

"Just about."

He looked across the table at my work. "Working ahead again."

"Hey. It's fun." I grinned and put down my pencil.

"Says you." He grinned back. "I'll go ask at the desk."

"I'll go check the card catalog."

Rick and the library assistant beat me to the stacks.

"Univac 1100 Series would be mainframe, wouldn't it?" Rick asked in a low voice.

The assistant nodded. "That's what I understand." 

I read the spine of a nearby volume quietly, "IBM 370."

"Mainframe," Rick replied. He read another. "PDP-11 series." He reached for the DEC manual.

"I think that's a minicomputer," I muttered.

The assistant nodded in agreement again. 

"So not a microcomputer." His hand paused. "Maybe later."

(The LSI-11 implementation of the PDP-11 did exist at the time. But it was not a single-chip microprocessor. It required four chips to function, was very expensive, and studying it would probably have taught lessons of less utility to high-school students than the microprocessors we were talking about in class would teach. It was a significantly more mature class of computer. But it would have been a dream to use. 

For the record, the T-11 single-chip implementation of the LSI-11 was still several years away.) 

I responded with a non-committal "Mmm hmm."

The library assistant pointed out a sign on the shelf I was looking at. "Just a reminder, these are reference works, and can't be checked out." 

Rick and I both nodded our acknowledgement.

"Understood," I said. 

"8080 -- Intel. Repetitious cover. RCA 1800? oh, COSMAC CDP 1802. F8? What's that?" Rick picked up a Fairchild manual.

"And these don't fit on the regular shelf." The library assistant pointed out the oversize shelf. 

"Ah, 6800," I said as I picked up the Motorola M6800 Programming Reference Manual from the shelf she had just indicated.

"Do you think you'll find everything okay?" she asked.

"Probably," Rick responded as he thumbed through the F8 manual. "For now. Thanks."

"The technology department has requisitioned manuals for a few more this semester," she volunteered. "the, uhm, Western Design Center 6502 and a couple of Texas Instruments microprocessors."

"9900?" Rick asked.

"I remember that one," she answered. "They seem to be really new products."

"They are," I confirmed. 

"If you give me your names and phone numbers, we can let you know when we get them."

We did so, and thanked her again, and she returned to the checkout counter.

Rick and I flipped through the manuals we had picked up.

"Wow." Rick muttered. "The F8 looks even more primitive than the 1802." 

He put the Fairchild manual on the returns shelf. "Maybe later."

"The explanations of the microprocessor instructions in this manual look pretty detailed." I handed him the 6800 Programming manual I had picked up.

"For me?" He gave me a lopsided grin.

"Unless you don't want it." 

He opened it up to a random page. 

I grabbed the M6800 Microprocessor Applications manual that had been next to it on the shelf. " I think I'm going to go sit down."

"Good idea." 

We went back to the study table. 

While Rick flipped randomly through the pages of the Programming manual, I opened the Applications manual to the table of contents and started scanning it, subvocalizing the sections. 

"Addressing modes, instruction set, pointer operations, branch and jump, looks like it repeats or summarizes a lot of the information in the Programming manual. Hmm. Plus the electronics side of things." 

Rick didn't say anything, just continued flipping through the pages. 

"Code examples. Addition and subtraction routines, multiplication and division, counting. Chapter two, section one point five." 

I opened to section 2-1.5 and read in a low voice to myself.

  L-D-A-A ALPHA ; Maybe, load A ALPHA?" 
  A-D-D-A BETA ; Add A BETA? 
  S-T-A-A GAMMA  ; Store A GAMMA?

I explained to myself, "I guess that means GAMMA = ALPHA + BETA, if GAMMA and ALPHA and BETA are all bytes. Load the left side, add the right side, store the result. And it looks like the same sort of thing for subtraction."

"Hang on," Rick said. "There's an appendix that has a description of the instructions. Let me see." Rick flipped pages. "L-D-A loads the contents of memory into the accumulator. And," He flipped pages back. "ADD," he read in English instead of reading each letter, "adds the contents of A-C-C-X and the contents of M and places the result in A-C-C-X. A-C-C-X means accumulator A or B?" He turned the Programming Manual so I could read the page.

"Mmmm -- immediate, direct page, indexed, and extended mode operands for each of accumulators A and B. Sounds right."

"And M is memory?"

"Apparently."

"Okay," he pulled it back and flipped pages forward. "S-T-A stores the contents of accumulator X in memory. The contents of accumulator X remain unchanged. I guess I can follow that. Not that I know what to do next."

"Add with carry?"

He flipped back a few pages. "A-D-C. Right here." 

"It's a start?"

"I hope so. Hmm." He flipped pages back and forth. 

"What?"

"I don't see any ADD to X instruction," he replied.

"Increment?"

He flipped pages. "I-N-X. increment X. Add one to X."

"Maybe it has to be done in memory and then loaded into X. Hang on, there are some tables of instructions here." I flipped back a bit. "Not this one." I flipped back a bit farther. "Accumulator and memory, ah, index register and stack pointer operations. Compare, decrement, increment, load, store, transfer between the stack and index registers. No add or subtract, so it looks like we have to add in memory and then load it. Or if it's quicker, use more than one increment or decrement instruction."

"Sounds like a lot of work."

I flipped some more pages. "I'm going to copy some of this out." And I got a sheet of loose-leaf paper out of my notebook.

"Copier over there?"

"Nah. I don't want the whole page, and the manual isn't going anywhere. And I think I might remember it better if I copy it." 

I copied the very short sequences for adding and subtracting multiple bytes while Rick went back to paging through the Programming Manual. 

After a few minutes, I said, "I think I'm going to take a guess at how to add B to X," and wrote down,

 STX X16 

Rick read, "Store X in X16. How do you know there is something called X16 that you can store X in?"

"I'm sure one of these manuals explains that." 

"You're making it up."

"For now. Uhm,"

  ADDB X16

"Mmm, how do I do this?" I flipped pages in the manual, looking at the sample code. "Oh, this would probably work."

  ADDB X16+1

"Add to accumulator B from X16 plus one," Rick read. "That would be one memory location beyond X16?"

"I think so."

"Your have B reversed from the example."

"I wonder if it matters." 

Rick give me a "Who knows?" shrug.

I continued. "If it doesn't,"

 LDAA X16
 ADCA 

Again I got stuck.

Rick suggested, "Just adding zero along with the carry might work?"

"Genius."

"Huh."

"Constant is immediate mode, and that uses the, uhm, pound sign." I continued,

 ADCA #0 
 STAB X16+1
 STAA X16 
 LDX X16

Rick read, "Load accumulator A from location X16, add carry immediate zero to A, store B at one beyond X16, store A at X16, and finally load X back in from X16."

We both stared at the code for maybe half a minute. 

"Sounds good, but I wonder if you could clear A and add A from X16 instead?"

"I wonder what would happen to the carry flag. Wait." I flipped back, looking for a table that had the load instruction in it. 

Rick flipped forward a bit.

"C-L-R clear," he said. "R stands for reset. Clears the carry flag."

"Maybe you could clear A first." I read from the table I found, "But loading the accumulator does not affect the carry flag."

"So that sounds like your sequence should work. That's a lot of work to go to every time you want to add B to X."

"There's got to be a way to avoid repeating that every time."

(There is a way to avoid repeating the code, of course, but that's for them to discover later. And what they came up with is not the most optimal, but it's pretty good first efforts. Way better than I and my friends in the reality you know could have done.) 

"I think I'm going to look at decimal adjust later," I commented to myself. "I wonder if carries are the same for decimal and binary."

Rick gave me another shrug, and I turned back to the manual and continued reading. 

"Hmm. It looks like they're saying that standard multiply by column works for binary like it works for base ten, but we knew that."

"You knew that."

"You did too."

"You told me about it once." 

I continued browsing. "Booth's algorithm? I wonder what that is." 

I turned a querying glance at Rick, and he returned a shrug.

"Maybe I'll copy this out later, too." 

I went back to the table of contents. "DMA -- direct memory access." 

"I wish I could make as much sense out of things as you do," Rick complained quietly, as he flipped pages.  

"What do you mean. You are making as much sense out of it as I am. Huh." I stopped flipping pages. "Scanning wand, UPC symbol." 

"Wand?" Rick grinned.

"Magic, I guess." 

We laughed. Quietly.

"Chapter six, design techniques. This looks like it might make a good textbook for our class. Hardware/software tradeoffs, hardware configuration, what's macro flow?"

Rick set the Programming manual down and moved around to my side of the table so he could get a better look.

I continued scanning the table of contents. "Chapter seven, development tasks." I continued silently to the bottom of the page. "Any idea what 'build virtual machine' means?"

"No idea." Rick shrugged and read the next entry, a little loudly. "The EXORciser?" He started humming the signature opening phrase of Mike Oldfield's "Tubular Bells", and we both laughed out loud.

We heard a shush from the checkout counter. I looked up and gave the library staff a thumbs-up, and the librarian who had helped us gave me a mock stern look, but with a real warning behind it.

"For getting the demons out of our designs?" I suggested, more quietly than before.

We both snickered. I glanced back to check with the librarian at the desk. She rolled her eyes.

"Chapter seven, page sixty-nine." I flipped to the specified page. That page had an image of a rather non-descript box. The swept-back front panel with an exaggerated lower lip might have been an attempt to make it look futuristic or something. The left three-quarters was occupied by a blank inset, and the only controls were to the right of the inset -- a keyswitch between two pushbuttons, with three indicator lamps, probably LEDs, above the controls, and the EXORciser logo above that.  

Rick shook his head. "Looks kind of like a squashed toaster oven." 

"No blinkenlights?" I turned the page. "Seventeen inches wide, nineteen deep, seven high. Forty-five pounds." (43.18 cm by 48.26 cm by 17.78 cm; about 20.412 kg.)

"The Altair 8800 looks a lot more interesting, what with all the switches and lights on the front panel."

"I wonder if we could put that kind of front panel on this."  

"I wonder how much it costs, and what you can do with it."

"I don't see any indication of prices. I might have asked about that in my letter of inquiry, if I had read this first." 

"Maybe they'll send you a price list anyway. I'll bet the SWTPC will be cheaper."

"Different purposes, probably." 

"Yeah, I think we need to know more about what these gadgets do before worrying about prices." 

We scanned more of the chapter without comment until Rick looked at his watch. 

"Time to go for lunch." 

"Whataburger?" 

"Yah." 

We put the manuals on the returns shelf, thanked the library staff on our way out, and headed north in Rick's car for the Whataburger down the road.

"Onions today?" Rick joked as we pulled into the drive-in.

I chuckled. "Is that relevant?" 

But I think I did order onions, lettuce, tomato, pickles, and cheese, with ketchup and mayonnaise. I usually did. Rick probably ordered grilled chicken with mayonnaise sauce, per his usual.

We talked about math and electronics while we ate, and then headed for Permian. 

TOC		Next
Where it starts

Copyright 2026 Joel Matthew Rees

[CUTTING ROOM FLOOR] 3809/2801: Early Morning Seminary through 6502 Indexing

Scraps from the cutting room floor,
from Early Morning Seminary to 6502 Indexing

This is the author's record of some of the stuff that got discarded; 
taken out of order, 
it does not tell things hidden things that happened,
or indicate directions the plot will take, etc. 

More than what is here,
you should want to read the story,
which begins here:  
https://joelrees-novels.blogspot.com/2025/09/3809-2801-tale-of-mcus-and-time-part-1-2801.html

2801
Terms of Engagement
Cutting Room Floor

Early Morning Seminary

TOC

 

she saw stu at the far end of the hall. 

Stu was one of the guys she had excused herself by the boyfriend at OHS.

Stu apologizes at.Katie's insistence 

Something else needs to happen as they head to school on different paths 

******************** 

"Well, he did take no for an answer, after I told him I wasn't available. That's better than some of the guys at school."

 

(I want to remind the reader -- and myself, maybe? that Joe is not the author. He does not exist in your reality. He seems to share some history with the author, but there is already significant divergence by this point.)  

 

I raised my eyebrows. "So we see how this strategy of minimal necessary truth works?" 

She nodded emphatically. "Yes. Let's." 

I opened the door.

We went inside. As we approached the classroom, I dropped her hand and wrapped my arm around her waist, and she settled in beside me.

Stu looked up and his jaw dropped  

 

"For keeping it close." Her voice was muffled. 

"Close?"

She lifted her head a little. "For letting me keep my fantasy a little longer."

"Uhm, ..." 

She put her hands against my chest and drew back. "Maralea called after you left last night. She'd been talking with Becca, and neither of them could believe you'd been dating me for the last two years."

"Joe! Yew dawg!" Rusty called out from the window of his family's car as he drove into the parking lot.

"Who's that?" 

"That's Rusty. He's my best friend at church. And his little sister, Liz." 

"Really never kissed a girl?"

We watched them park.

"Didn't I mention that?"

"No, you didn't."

"Not bragging, by the way." 

Rusty and Liz got out and waved and headed over to meet us. 

We waved back. 

"I was wondering if I should accept that as a challenge."

We both chuckled. 

"She's really cute."

"Yeah. Spunky, too. Is 'spunky' too archaic?"

"Probably not." 

[tracking the rest of the changes got too hard.]

"In art class at Hood, Buddy asked you if you were a virgin, and you said, of course you weren't."

"Ah. That. Something I should have cleared up the next day, but didn't have the courage."

"But you've never kissed."

I scratched the back of my head. "I don't know about you, but the only time I had heard the word 'virgin', up until junior high, was in the context of Mary being pregnant with Jesus." 

Sapphire's mouth dropped open, then closed. 

"Okay. So I'm not the only one, although I got it cleared up during elementary." 

"The sex ed class had me confused, but I looked it up after Buddy asked."

"But then you didn't want to be teased for misunderstanding." She gave me a wry smile.

"Yep. Well," I had to stop and think for a moment. But I continued. "And I was, well, I am still not really clear on something."

"Oh?"

I took a deep breath. "Masturbation."

She let out an explosive but quiet laugh. 

"Does that make a guy not a virgin?" 

"If it did, we wouldn't have very many virgins. Guys or girls."

I processed that. "But there are less  

 

 

Rusty bobbed his head. "Liz and I should probably head inside." 

 

 

"My, uh, girlfriend." I turned back to Shelly. "From Hood." I was choosing my words carefully.

Shelly's expression became a little sharp. "You have a girlfriend? Since when?"

I looked back at my mom for help. She just gave me a "You got yourself into this." smile.

I dodged. "We've known each other since seventh grade. I guess we've been getting a little more serious about each other recently." 

Mom blinked and nodded.

"I really don't think she'll mind," I added.

Shelly's expression shifted with her focus. 

From behind me, Becca said, "Good morning, Joe. Why haven't you invited Sapphire to Seminary yet?"

It took me a fraction of a second to shift gears. "I didn't think her Mom would --" I started to turn around.

Hands covered my eyes from behind before I could turn, hands I would not have recognized the morning before.

"Good morning, Sapphire," I said with a chuckle.

I felt as much as heard her giggle through her arms. In front of me, I thought I heard Shelly breath out sharply. 

"I guess your mom figured it would be okay if it was Becca and not me inviting you?" 

Maralea and Becca broke out laughing behind me. Sapphire's hands slipped down, and she hugged me. I felt her laughter against my back.

"Good morning, Joey. You guess right, except it was Maralea who invited me."

"I'm glad someone is on top of things." I gave her hands a squeeze, then slipped one arm behind her and brought her beside me.

"Sapphire, this is Shelly. She's the girl I took to see that Pink Panther movie last year, after my birthday -- when I could finally drive by myself without someone eighteen or older riding shotgun."

"Hi, Sapphire." Shelly's face was a mask.

"Hi, Shelly. That's a fun movie," Sapphire smiled.

Shelly's mask resolved into a lopsided smile. "I guess I don't like British slapstick. And I was kind of expecting the animation more than Peter Sellers."

"I should have found out more about the movie before I asked you to see it." 

"That's okay. I learned that we don't have the same taste in movies."

"Since you're here, Sapphire," I began.

Shelly interrupted me. "Never mind, Joe. It's okay."

Sapphire raised her eyebrows with a smile. "What kind of friend would I be if I objected to giving a friend a ride to school?" 

I looked from Sapphire to Mom to Shelly. 

Sister Rudd blinked. "You wouldn't mind?"

"It's not like we're engaged or anything." She turned and gave me a sly wink. "Yet."

I nodded absently. "Yet. Why do I feel threatened by that?"

She smirked. Then she turned and reached out for Shelly's hand. "I'm glad to meet you, Shelly. I hope we can be friends." 

Shelly nodded suddenly. "I hope so, too." 

Sapphire gave me a side hug. "Can you guys go in ahead of us? I need to talk with Joe."

"Now I'm Joe again."

Sapphire gave me another smirk.

Nobody disagreed, and Becca, Maralea, and Shelly went inside, and my mom walked with Sister Rudd over to her car.

Sapphire and I walked away from the back entrance to the sidewalk, across the street from Bowie Junior High. Her smile went away and she buried her face in my chest. "Thanks." 

I wrapped my arms around her shoulders. "Mmm?"

"For keeping things close." Her voice was muffled. 

"Close?"

"Quiet?" She put her hands against my chest and drew back. "Maralea called after you left last night. She'd been talking with Becca, and neither of them could believe you'd been dating me for two years."

"Yeah, that's going to be hard to pull off here."

"So I came clean. Maralea said she would keep it quiet, even though she wouldn't lie. This morning, when they picked me up, Becca agreed the same." 

"It seems like, at church, everyone knows who's dating who and all."

"Kiss and tell?"

"Kiss and get found out. And I'm pretty much known for being a lone wolf. And having never been kissed." 

"Joe! Yew dawg!" Rusty called out from the window of his family car as he drove into the parking lot.

"That's Rusty. He's my best friend at church. And his little sister, Liz." 

"Really never been kissed?"

We watched Rusty park.

"Didn't I mention that?"

Rusty and Liz got out and headed over to meet us. 

"She's cute." Sapphire didn't mention the scar from Liz's surgery for cleft palate. 

"Yeah."  

"Should I be jealous?"

"She doesn't pay attention to me." 

"Who doesn't pay attention to you?" Liz asked. 

I slapped hands with Rusty. "Sapphire, meet Rusty, and Rusty's little sister Lizzie."

Shelly interrupted me. "Never mind, Joe. It's okay."

"What's okay?" Sapphire looked at me inquisitively. 

"Shelly's mom won't be able take her to school from here for a while, so she was thinking Shelly could catch a ride with me."

Sapphire put on airs. "And you're asking me if I care?" 

"Well?"

Her airs tilted. "What kind of friend would I be if I said she had to walk?"

"You wouldn't mind?" Shelly's mom asked.

"I'm his girlfriend, not his wife, and even if I were his wife, I trust him." Sapphire gave me a squeeze. "Can you guys go in ahead of us? I need to talk with Joe."

"Now I'm Joe again."

Sapphire gave me another smirk.

"I guess everyone at your church will know we haven't been going steady for two years? Becca and Maralea were adamant."

"Well, you know, I figured you'd be okay with me giving Shelly a ride without even mentioning you to Shelly, but Mom seemed to think I needed to talk to you about it. It's convenient that you're here."

Sapphire gave me a moue.

"No?"

Rusty called out to me from the church parking lot, and I waved and answered. He and his little sister, Lizzy Lou, waved as they entered the building. 

"Your mom was giving you a way to let Shelly know you have a girlfriend."

"Oh. Well, anyway, Shelly wanted to know how long we've been together, and I said we'd known each other since seventh grade, and we had been getting more serious about each other recently."

"How true is that?"

"True as far as it goes, isn't it?"

"Uh huh. What do we do if people ask what we've been doing for two years?"

"Tell them it's none of their business."

She shook her head.

"But not in so many words unless they demand to know." 

"We've never had sex."

"Of course. Nor do we make out." 

"I've told a few people that my boyfriend at OHS and I are pretty close, but that doesn't really require making out. It looks like I've been the more committed one, though, since you've dated. How many girls, how much?"

"A couple of group dates that were arranged as youth activities here at church, and one date with Shelly, and that's it. My crush on you is partly to blame for that, by the way." 

"Okay, I think I haven't said anything that I can't fudge that into just me being more committed. Have we kissed?"

"I've told several people here at church, Shelly included, also at school, that I've never kissed a girl, so I think not." 

"Might be difficult to convince some of my friends. I almost kissed you now." 

"Oh. So many times we've almost kissed in the last, uhm, twenty-four hours."

"Are you disappointed?" She smiled lopsidedly at me.

"That you were tempted or that you didn't? Yes."

She giggled. "We should have talked about this yesterday."

"We'll need to talk about it again. Let's go inside before we miss the opening prayer."

"Kiss?"

"Not yet. Give me time."

She gave me a sideways hug as we turned to walk inside together. 

 

 

 "What did you tell Shelly about us?" 

"I fudged a little. Was a little vague, didn't lie, didn't tell the whole truth."

"Will she be upset?"

"Hard to say. But I guess it's what I chose when I chose to go along with this charade."

Sapphire's face clouded.

"I know, it's real even though it's a charade." I gave her a sardonic grin. "At some point, once we have an idea which way we're going with this, we'll have to ...." I trailed off and my grin disappeared, and I kissed her. 

 

 

"Sure. We can do that."

"Thanks. Thank you, Sister Reeves." Shelly turned and waved to her mom, who was waiting in their car.

My mom went over to talk to Sister Rudd while Shelly and I went inside.

In the classroom, Shelly waited until I had put my books down and took a desk away from where I had chosen. 

Rusty Brennan came in with his little sister and said hello. Rusty sat by me. Lizzy sat by Shelly. Several other kids came in and sat down, exchanging the usual greetings.

Becca and Maralea came in and saw me and waved hello, and took desks in the middle of the room. 

(I'm sure I lost a lot of readers on the shift to the teen romance that never was. And I'm going to lose more shifting back to technology. At least, for the current chapters, the tech is real. But first, there's some loose ends from the last chapter.) 

The alarm rang at 5:45 the next morning, and I headed sleepily to the shower. The stream of the events of the previous day blasted me along with the stream of water, and I wished I had thought to set the alarm for a few minutes earlier. Or maybe not.

Satisfying myself with the usual soap-only-where-it-counts, and promising myself to set the alarm at least five minutes earlier that night, I toweled off, threw on the clothes I had worn the day before, and went into the kitchen for toast and peanut butter.

"Good morning Joey." Mom was at the stove. "Boiled egg this morning?"

"Oh. Sounds good. Thanks, Mom." I gave Mom a hug, grabbed some bread from the counter behind her, and loaded the toaster.

"You're going to need more complete protein if you're going to be doing all this using your muscles."

"Peanut butter's not going to be enough?" I reached into the fridge and pulled out the milk and the dish of raw vegetables Dad had cut the night before.

"I think not. That's yesterday's shirt, isn't it?"

I looked down at my shirt. It was a blue casual button-down shirt, didn't look that wrinkled. I sniffed, and I caught a little of my own body odor. "Not a good idea?"

She shook her head.

I set the milk and vegetables on the table and went back to my room to grab a clean swedish knit rayon tee with an air balloon print on front, tossing the previous day's shirt in the hamper as I passed the bathroom again on the way back to the kitchen. I pulled the clean shirt on over my head as I passed through the living room and ignored the scratchy feel. 

Mom looked at the shirt with an air of dissatisfaction as she spread peanut butter on a slice of my toast, but she didn't say anything. 

"You think I should wear something else?" I got out a plate and Mom put the the peanut-buttered toast on it, picking up the other slice to repeat. 

She shrugged. 

I put two more slices in the toaster and got out more plates. "Are the eggs ready to cool?"

"Yep." Mom put the peanut butter toast on my plate.

I poured the boiled water out of the pan, holding the eggs in with the lid, and poured cold tap water over the eggs, repeating several times until the eggs were cool, then grabbed one and started peeling it while Mom buttered the second batch of toast with regular butter (real butter, not margarine) for herself. I peeled another egg for Mom, and we sat down. I said a quick blessing, and we ate. 

Dad came in as we finished up, rubbing his hair with a towel.

"Buenos dias."

"G'mornin' Dad. Want me to peel you one of Momma's eggs?"

"No, I've got it. You guys get to Seminary."

I grabbed my books and Mom grabbed something she wanted to work on in the library at church, and I drove, taking my usual quick route past Polyanna Park and up University Boulevard.

Mom didn't mention Sapphire on the way, giving me room to think.

Shelly Rudd met us in the parking lot.

"Hi, Joe. Sister Reeves."

"Hey."

"God morning, Shelly. How are you doing?"

"Okay, uhm, Joe, don't get any ideas, but can I ask for a ride to school after seminary? My mom needs the car today."

I'd taken Shelly to a movie a year before, and she had made it clear at the time she wasn't interested in going out again.

 "To school?" I looked at Mom, and she raised her eyebrows, but nodded. "No problem. But I'll but at Permian after lunch, so you'll need another ride home."

"That's okay. Mom will pick me up after school."

"Sure. We can do that."

"Thanks. Thank you, Sister Reeves." Shelly turned and waved to her mom, who was waiting in their car.

My mom went over to talk to Sister Rudd while Shelly and I went inside.

In the classroom, Shelly waited until I had put my books down and took a desk away from where I had chosen. 

Rusty Brennan came in with his little sister and said hello. Rusty sat by me. Lizzy sat by Shelly. Several other kids came in and sat down, exchanging the usual greetings.

Becca and Maralea came in and saw me and waved hello, and took desks in the middle of the room. 

Other than that, nothing really interesting happened. We talked about Moses and about how the book of Genesis was Moses teaching the children of Israel some of what we learn in our temples, if I remember right. And we talked about random stuff in between talking about the scriptures.

After class, I gathered my books to head to the library. As I passed Becca and Maralea on my way out, they looked up.

Becca started, "Joe, ...." But she stopped.

"Yeah?"

She seemed to change her mind. "You'll be there after school?"

"Planning on it."

"Uhm 'kay. See you then." 

"Yeah. See you there."

Shelly was talking to Christa, so I waited for a break in the conversation. "Shelly, I'll be in the library with my mom."

"I'll catch up with you."

Maralea and Becca looked at me and then at each other, but didn't say anything. 

I helped my mom with a few things in the library, and we cleared things away and turned out the lights.

Shelly came up as we were closing the door.

"Sorry to keep you waiting," she said.

"No problem."

"I can walk to school if  

 

 

 

 

 

 

 

Dad came in and grabbed a boiled egg, too, and  

nd we sat down for a quick blessing and breakfast. 

 

 

 

Mom rode with me to early morning Seminary class at the church the next morning, so she could drive the Colt home. While she waited for Seminary to finish, she would be taking care of library business.

Becca and Maralea were talking by the rear entrance porch when Mom and I walked up the sidewalk.

"Good morning girls." Mom greeted them. 

I also greeted them. "Mara." I nodded. "Becca."

They looked at my Mom and then at me.

"Good morning." Becca gave my mom one of those looks that women use to communicate silently.

"Hi." Maralea gave me a similar look, not that I understood anything by it.

"I think I'll just go ahead and get started in the library," Mom said, giving me a look that said, "This is your ball to return, kid." 

"Ah. Yeah." 

Mom preceded me into the building.

As the door closed, Becca turned to me. "We're both a little worried about something."

"What's that?"

"Sapphire." Maralea said, as if her name explained something.

I debated being obtuse, chose against it. Just waited for elucidation, but none was forthcoming.

I decided the obtuse approach might be more direct after all. "Sapphire?"

"And you," Becca added.  

I thought for a long moment. "Okay. And what are you worried about?"

Maralea said, "She's out of your league." 

Becca added, "You don't know how to, uhm, you don't have the social ski ..."

I let her trail off.

"I'm not being judgemental."

I replied, "It's not exactly untrue. I do lack social skills."  

Maralea took a turn. "Look, everybody knows you're weird because you like being weird, but ... "

I let her trail off, too.

Maralea tried again. "She's a danger. To you."

"Oh." I nodded. "Now I see." I raised my eyebrows. "You might have a point. Rick said he thought she was out of my league, too."

Both of them nodded their heads enthusiastically.

"So should Hec and Rick and I just decide we don't like cheer dance, after all?"

Becca shook her head emphatically. "No, that's not ..."

Maralea looked thoughtful. "I guess maybe we should give you guys a chance to see if you like it. Ms. Michaels would shoot us if we chased you away. But that's not what we're worried about."

"So, ..." I prompted.

Maralea said, "Sapphire has a boyfriend."

Becca added, "At OHS. He's supposed to be a pretty tough guy."

"Oh, yeah. That. She mentioned it to me."

"Shouldn't you be worried?" Becca asked. 

"About her boyfriend?" I shook my head. "I'm not sure why."

"Do you know him?" Maralea asked.

"Pretty well, I think." 

Both suddenly seemed at a loss for words.

"So should we go into class?" I suggested. "They should be starting pretty soon."

They looked at each other.

I opened the door and waited, and they turned and somewhat irresolutely entered the building in front of me.

When we passed the library, I waved to my mom, who was already typing up something for the spirit duplicator. She stopped typing and waved back.

Shelly came in from the other hall. I said good morning, and Maralea and Becca stopped to talk to her. 

(Shelly was the first girl I ever asked out, at the beginning of the previous year, our junior year. I had just gotten my driver's license, and took her to the Pink Panther movie that had recently come out. I thought she was enjoying the movie up until the gag with the vacuum cleaner. 

Yeah, that scene made me uncomfortable, too, and made the whole movie feel off-color. I probably should have apologized. She wasn't interested in going out with me again.)

In the classroom, I sat at the desk on the front row at the far wall. Maralea, Becca, and Shelly came in shortly, and Becca sat beside me, Shelly behind her, and Maralea behind me, all without comment.

The room could seat twenty students in a pinch, but there were only sixteen desks set up. Maybe seven other students were standing around or already seated. 

The bishop's son, Sam, watched us from his perch on the other side of the room. He looked like he was about to say something, but his father entered the room and cleared his throat.  

Sam got off his desk and sat down, others who had been standing also sat, and Bishop Karlson began the lesson. 

The morning's lesson covered what Bishop Karlson felt were salient points in the introductory parts of Abraham and Moses in the Pearl of Great Price. Some of the students, including the three around me, participated, some just sat. 

I contributed when I thought I had something useful to say. 

After class, I went into the library to help Mom, and Becca and Maralea lingered by the library door. Mom invited them in, and they gave her a hand sorting some materials.

Becca commented off-handedly, as she shuffled through some Bible pictures, "Joe, it's not that we don't want you to hang around with Sapphire, it's just that we don't want either you or her to get hurt."

I was operating the duplicator. I paused, and replied, "Yeah, and Rick said something like that, as well. Sapphire and I talked about a lot of things last night, and I think things will be okay." I started cranking the duplicator again, counting the copies. "Fifteen should be enough?" I stopped cranking.

Mom said, "Yeah. Let's get those ready for tomorrow and get you to school, Joe. Do you girls need a ride?"

Becca replied, "No, my mom's waiting for us." 

In the parking lot, Mom stopped to talk with Becca's mother about church things for a couple of minutes while I went to the Colt and started the engine.

She wrapped it up quickly, and I drove to OHS, where I stopped in front of the auditorium and grabbed my books. Mom slipped into the driver's seat and gave me a wave as she left.

Chem in first period and home room in the second (half) period had nothing of note going on, and I went out into the parking lot to meet Rick.

Rick gave me a lookover, then got closer and sniffed.

"No, I'm not wearing cologne!" I assured him.

"Just checking to see if you smell of Sapphire."

I laughed, and he did, too, and he unlocked the doors and we got in.

"I guess it's silly. But you do seem to have something of the influence of girls on you." Rick started the engine, looked behind us and backed out of the parking space. 

I cocked my head and nodded. "Becca and Maralea expressed concern at Seminary. They agree with you that Sapphire is out of my league."

"I was just blowing smoke." He shifted to drive and we left the school.

"They sat next to me during class. I don't know why. But surely that hasn't tainted me."

He shook his head. "I'm guessing it's Sapphire's influence."

"Possibly. I spent more time with her yesterday than I think I have ever spent in a day with a girl I wasn't related to."

"You didn't make out?" 

"No. We practiced some lifts while my sisters spotted. Then her folks showed up and talked with my folks."

"Say what?"

"Her mom was worried about me being a Mormon, but it turns out my dad taught them at OC a long time ago, and so they aren't worried."

"Hmmmm." 

"And then we studied. We talked about some things on the way back to her house, and that was about it."

"Maybe it's just my imagination. Time and energy I could be putting into calculus."

We talked about math and electronics until we got to the OC parking lot and headed to class.

The calculus class was in the same building as Dad's office and classrooms, down the hall on the second floor. But Dad was in class when we went by. 

There wasn't really anything of note that happened in Calculus class. I don't remember if that was the day Professor White said that correct solutions in math were sexy.

After class, as we packed up our books, I suggested, "Hey, can we stop by the library?"

Rick looked at me.

"They might have some books for the 6800."

"Good idea." 

In the library, Rick went to the desk while I went to the card catalog. A librarian showed him to the reference shelves just as I pulled up a card with "REFERENCE SECTION in red at the top. I put the drawer back in and went to the reference section. 

"We can't let you check these out," the librarian was explaining when I got there. "They're too much in demand." 

We thanked her and looked at what they had, manuals for the 6800, the 8080, and the 1802. Also for the Fairchild F8, and for the IBM 360 mainframe processor and the PDP 11 minicomputer processor. 

"Will you be getting manuals for the 6502 and 9900?" Rick asked

"I think I read those numbers mentioned in our requisition paperwork."

"That would be pretty cool," I said.

She left, and after a bit of blindly thumbing around the 6800 manuals, we decided we didn't really understand enough to make use of them yet.

"Well, now we know we can find them here," Rick said. 

We left and headed for the Whataburger down the road, for lunch.

"Onions today?" Rick asked.

I chuckled. "Is that relevant?" But I did ask for onions, with the pickles, lettuce, tomato, and cheese on my burger. No sauce, though.

We ate in his car and headed for Permian, talking a bit more about calculus on the road. 

As we got out of the car in the parking lot, Rick said, "Look who's here."

Sapphire was standing by the door nearest the parking lot. She waved when she saw us, and came to meet us.

"What's up?" I asked as she joined us.

"Hi, Rick."

Rick nodded in greeting. 

"Nothing really. Mara and Becca were talking about you at lunch. And I thought I'd have time to say hi before class."

"Well, Hi!"

She grinned at me. 

"They asked me if I knew about your boyfriend at OHS."

"I heard you didn't enlighten them."

"I did tell them I thought I knew your boyfriend pretty well."

Rick chuckled and shook his head.

"So they said. I think they spent the whole time at lunch trying to figure out why you weren't worried."

I grinned and she grinned back. 

We stopped outside the door and I looked around and gave her a quick hug.

Rick asked, "What am I supposed to say if Maralea asks me about this?" He gave us a lopsided grin. 

The lab was the room neares the door, so we stopped near the entrance.

 

*********** 

Sapphire met us on the way in from the parking lot.

***** 

 

"Becca and Maralea told me that the three of you had come to some sort of agreement." 

I raised my eyebrows and shrugged. "They agreed that it was not a good idea for Rick and Hec and me to quit Cheer Dance."

She looked at me, puzzled.

"And I guess I agreed with them about that."

Rick laughed.

Sapphire looked relieved, and she grabbed my arm and we entered the south east wing together. "Nothing else?"

"They are worried about what your boyfriend at OHS might do to me. Maybe I should be worried, too." I grinned sideways at her.

She laughed sheepishly.

Rick stopped suddenly. "Joe?"

I turned and gave him an amused look.

Sapphire turned, also, biting her lip.

RIck laughed and shook his head, and started walking again. "I guess you can be a danger to yourself sometimes."

Sapphire giggled.

I grinned at her, and she gave me a hug.

"I guess I'll have to explain someti ..."

"PDA!" 

All three of us turned. Mark came up from behind, laughing. He passed us without further comment and entered the lab.

Sapphire quietly gave my hand a squeeze, and went to her class,.

Rick and I entered the electronics lab. 

Mr. Mori had the projector fired up and had his first transparency on it, waiting for the bell to ring. 

 

***Mention my calculator watch, laugh about programmability -- need the mention for the dream stuff

 

******

(All the people I've lost on the shift to the teen romance that never was. I guess I'll lose a bunch going back to technology. But first there's some loose ends from the last chapter.) 

Mom rode with me to early morning Seminary class at the church the next morning, so she could drive the Colt home. While she waited for Seminary to finish, she would be taking care of library business.

Becca and Maralea were talking by the rear entrance porch when Mom and I walked up the sidewalk.

"Good morning girls." Mom greeted them. 

I also greeted them. "Mara." I nodded. "Becca."

They looked at my Mom and then at me.

"Good morning." Becca gave my mom one of those looks that women use to communicate silently.

"Hi." Maralea gave me a similar look, not that I understood anything by it.

"I think I'll just go ahead and get started in the library," Mom said, giving me a look that said, "This is your ball to return, kid." 

"Ah. Yeah." 

Mom preceded me into the building.

As the door closed, Becca turned to me. "We're both a little worried about something."

"What's that?"

"Sapphire." Maralea said, as if her name explained something.

I debated being obtuse, chose against it. Just waited for elucidation, but none was forthcoming.

I decided the obtuse approach might be more direct after all. "Sapphire?"

"And you," Becca added.  

I thought for a long moment. "Okay. And what are you worried about?"

Maralea said, "She's out of your league." 

Becca added, "You don't know how to, uhm, you don't have the social ski ..."

I let her trail off.

"I'm not being judgemental."

I replied, "It's not exactly untrue. I do lack social skills."  

Maralea took a turn. "Look, everybody knows you're weird because you like being weird, but ... "

I let her trail off, too.

Maralea tried again. "She's a danger. To you."

"Oh." I nodded. "Now I see." I raised my eyebrows. "You might have a point. Rick said he thought she was out of my league, too."

Both of them nodded their heads enthusiastically.

"So should Hec and Rick and I just decide we don't like cheer dance, after all?"

Becca shook her head emphatically. "No, that's not ..."

Maralea looked thoughtful. "I guess maybe we should give you guys a chance to see if you like it. Ms. Michaels would shoot us if we chased you away. But that's not what we're worried about."

"So, ..." I prompted.

Maralea said, "Sapphire has a boyfriend."

Becca added, "At OHS. He's supposed to be a pretty tough guy."

"Oh, yeah. That. She mentioned it to me."

"Shouldn't you be worried?" Becca asked. 

"About her boyfriend?" I shook my head. "I'm not sure why."

"Do you know him?" Maralea asked.

"Pretty well, I think." 

Both suddenly seemed at a loss for words.

"So should we go into class?" I suggested. "They should be starting pretty soon."

They looked at each other.

I opened the door and waited, and they turned and somewhat irresolutely entered the building in front of me.

When we passed the library, I waved to my mom, who was already typing up something for the spirit duplicator. She stopped typing and waved back.

Shelly came in from the other hall. I said good morning, and Maralea and Becca stopped to talk to her. 

(Shelly was the first girl I ever asked out, at the beginning of the previous year, our junior year. I had just gotten my driver's license, and took her to the Pink Panther movie that had recently come out. I thought she was enjoying the movie up until the gag with the vacuum cleaner. 

Yeah, that scene made me uncomfortable, too, and made the whole movie feel off-color. I probably should have apologized. She wasn't interested in going out with me again.)

In the classroom, I sat at the desk on the front row at the far wall. Maralea, Becca, and Shelly came in shortly, and Becca sat beside me, Shelly behind her, and Maralea behind me, all without comment.

The room could seat twenty students in a pinch, but there were only sixteen desks set up. Maybe seven other students were standing around or already seated. 

The bishop's son, Sam, watched us from his perch on the other side of the room. He looked like he was about to say something, but his father entered the room and cleared his throat.  

Sam got off his desk and sat down, others who had been standing also sat, and Bishop Karlson began the lesson. 

The morning's lesson covered what Bishop Karlson felt were salient points in the introductory parts of Abraham and Moses in the Pearl of Great Price. Some of the students, including the three around me, participated, some just sat. 

I contributed when I thought I had something useful to say. 

After class, I went into the library to help Mom, and Becca and Maralea lingered by the library door. Mom invited them in, and they gave her a hand sorting some materials.

Becca commented off-handedly, as she shuffled through some Bible pictures, "Joe, it's not that we don't want you to hang around with Sapphire, it's just that we don't want either you or her to get hurt."

I was operating the duplicator. I paused, and replied, "Yeah, and Rick said something like that, as well. Sapphire and I talked about a lot of things last night, and I think things will be okay." I started cranking the duplicator again, counting the copies. "Fifteen should be enough?" I stopped cranking.

Mom said, "Yeah. Let's get those ready for tomorrow and get you to school, Joe. Do you girls need a ride?"

Becca replied, "No, my mom's waiting for us." 

In the parking lot, Mom stopped to talk with Becca's mother about church things for a couple of minutes while I went to the Colt and started the engine.

She wrapped it up quickly, and I drove to OHS, where I stopped in front of the auditorium and grabbed my books. Mom slipped into the driver's seat and gave me a wave as she left.

Chem in first period and home room in the second (half) period had nothing of note going on, and I went out into the parking lot to meet Rick.

Rick gave me a lookover, then got closer and sniffed.

"No, I'm not wearing cologne!" I assured him.

"Just checking to see if you smell of Sapphire."

I laughed, and he did, too, and he unlocked the doors and we got in.

"I guess it's silly. But you do seem to have something of the influence of girls on you." Rick started the engine, looked behind us and backed out of the parking space. 

I cocked my head and nodded. "Becca and Maralea expressed concern at Seminary. They agree with you that Sapphire is out of my league."

"I was just blowing smoke." He shifted to drive and we left the school.

"They sat next to me during class. I don't know why. But surely that hasn't tainted me."

He shook his head. "I'm guessing it's Sapphire's influence."

"Possibly. I spent more time with her yesterday than I think I have ever spent in a day with a girl I wasn't related to."

"You didn't make out?" 

"No. We practiced some lifts while my sisters spotted. Then her folks showed up and talked with my folks."

"Say what?"

"Her mom was worried about me being a Mormon, but it turns out my dad taught them at OC a long time ago, and so they aren't worried."

"Hmmmm." 

"And then we studied. We talked about some things on the way back to her house, and that was about it."

"Maybe it's just my imagination. Time and energy I could be putting into calculus."

We talked about math and electronics until we got to the OC parking lot and headed to class.

The calculus class was in the same building as Dad's office and classrooms, down the hall on the second floor. But Dad was in class when we went by. 

There wasn't really anything of note that happened in Calculus class. I don't remember if that was the day Professor White said that correct solutions in math were sexy.

After class, as we packed up our books, I suggested, "Hey, can we stop by the library?"

Rick looked at me.

"They might have some books for the 6800."

"Good idea." 

In the library, Rick went to the desk while I went to the card catalog. A librarian showed him to the reference shelves just as I pulled up a card with "REFERENCE SECTION in red at the top. I put the drawer back in and went to the reference section. 

"We can't let you check these out," the librarian was explaining when I got there. "They're too much in demand." 

We thanked her and looked at what they had, manuals for the 6800, the 8080, and the 1802. Also for the Fairchild F8, and for the IBM 360 mainframe processor and the PDP 11 minicomputer processor. 

"Will you be getting manuals for the 6502 and 9900?" Rick asked

"I think I read those numbers mentioned in our requisition paperwork."

"That would be pretty cool," I said.

She left, and after a bit of blindly thumbing around the 6800 manuals, we decided we didn't really understand enough to make use of them yet.

"Well, now we know we can find them here," Rick said. 

We left and headed for the Whataburger down the road, for lunch.

"Onions today?" Rick asked.

I chuckled. "Is that relevant?" But I did ask for onions, with the pickles, lettuce, tomato, and cheese on my burger. No sauce, though.

We ate in his car and headed for Permian, talking a bit more about calculus on the road. 

As we got out of the car in the parking lot, Rick said, "Look who's here."

Sapphire was standing by the door nearest the parking lot. She waved when she saw us, and came to meet us.

"What's up?" I asked as she joined us.

"Hi, Rick."

Rick nodded in greeting. 

"Nothing really. Mara and Becca were talking about you at lunch. And I thought I'd have time to say hi before class."

"Well, Hi!"

She grinned at me. 

"They asked me if I knew about your boyfriend at OHS."

"I heard you didn't enlighten them."

"I did tell them I thought I knew your boyfriend pretty well."

Rick chuckled and shook his head.

"So they said. I think they spent the whole time at lunch trying to figure out why you weren't worried."

I grinned and she grinned back. 

We stopped outside the door and I looked around and gave her a quick hug.

Rick asked, "What am I supposed to say if Maralea asks me about this?" He gave us a lopsided grin. 

The lab was the room neares the door, so we stopped near the entrance.

 

*********** 

Sapphire met us on the way in from the parking lot.

***** 

 

"Becca and Maralea told me that the three of you had come to some sort of agreement." 

I raised my eyebrows and shrugged. "They agreed that it was not a good idea for Rick and Hec and me to quit Cheer Dance."

She looked at me, puzzled.

"And I guess I agreed with them about that."

Rick laughed.

Sapphire looked relieved, and she grabbed my arm and we entered the south east wing together. "Nothing else?"

"They are worried about what your boyfriend at OHS might do to me. Maybe I should be worried, too." I grinned sideways at her.

She laughed sheepishly.

Rick stopped suddenly. "Joe?"

I turned and gave him an amused look.

Sapphire turned, also, biting her lip.

RIck laughed and shook his head, and started walking again. "I guess you can be a danger to yourself sometimes."

Sapphire giggled.

I grinned at her, and she gave me a hug.

"I guess I'll have to explain someti ..."

"PDA!" 

All three of us turned. Mark came up from behind, laughing. He passed us without further comment and entered the lab.

Sapphire quietly gave my hand a squeeze, and went to her class,.

Rick and I entered the electronics lab. 

Mr. Mori had the projector fired up and had his first transparency on it, waiting for the bell to ring. 

 

*****

 

She was the bi-ward librarian, and used the morning time to take care of library business, sorting materials, trying to determine what materials had been borrowed and by whom, using the spirit duplicator (which we mistakenly called the ditto machine) to make small runs of materials for classes and such. 

After Seminary, on days Rick was driving, she would go with me to OHS and then drive the Colt home. 

 

 ***Mention my calculator watch, laugh about programmability -- need the mention for the dream stuff

 

 

****

"Okay, Harvey, what's peculiar about the 6502?"

"It has two indexes, but they are both 8 bits wide?"

"That's one thing." 

"If the constant base address can be sixteen bits wide, we have the opposite problem from the 6800."

"How so?"

"A sixteen-bit constant base can put the array anywhere, and we'd be okay as long as the offset is less than 256. But that only works when we know where it is in advance."

"That's true. The 6502 provides this mode, and I understand that we can do with both X and Y. Would you be willing to diagram it for us?"

Harvey hesitated. "I guess I can give it a try." He approached the white board.

 

*** 

 

 

"Joe left the steps to add the two bytes out of the diagram. Is that confusing to anyone?"

Several of the guys raised their hands.

"Okay, Joe, do you mind if I take over for a bit?"

"Sure. I mean, no problem."

"Okay, we're going to role play the computer." Mr. Mori grinned and paused for effect before continuing. "When I call you, stand up. Joe, you and Rick remain standing. Scott, you're direct page memory location X16. But we need an actual address. Rick, what's the actual address?"

"I don't know. Ten, maybe?"

"Ten it is. Barry, you're location X16 plus one. What's your address?"

"Uh, eleven?"

"Okay, Bob, you're accumulator B. What do you have when the code starts here?"

"Four."

"Right. Karl, you're the index register, X. What have you got?" 

"N."

"We need a concrete value for N so Barry and Scott know what hits them." 

"Anything less that 65,536?"

"What do you say, Joe?"

"I have the impression that addresses above 32,767 get used for stuff, so maybe below that."

"How about 31,999?"

I shrugged "I think it would be okay, but we have to divide that into high byte and low byte."

Karl looked at Barry with a grin. "You do the math."

"Well, 32,000 divided by 256," He looked at Mr. Mori, who nodded. "Is a hundred twenty-five, so the high byte is 124."

Scott nodded. "And the low byte is 255."

"Okay. But you don't have those yet. What do you have?"

Barry said, "Something random?"

"Probably."

"Okay, I have seventeen."

Scott said, "I'll have a hundred seventeen." 

Mr. Mori said, "Now we need someone to be the carry flag. Mark?" 

"Okay. I'm random to start, too?"

"Yeah."

"No carry, then." 

"Okay, Joe, read the instructions."

"Store X at location ten."

Karl said, "Scott first?"

"Yeah."

"Scott gets one twenty-four." 

Scott said, "124."

"Barry gets two fifty-five."

Barry said, "255."

I said, "Now, add B from location eleven."

Barry said, "255."

Bob said,  "Four and two fifty five makes --" he stopped. "I can't hold anything bigger than 255, so it wraps around to three, with a carry, I guess?"

Mark said, "Carry." 

I continued, "Store B to location eleven." 

Bob said, "Three."

Barry said, "Three."

Mark said, "Carry unaffected?"

I said, "Right. Now load B from location ten."

Scott said, "One twenty-four."

Bob said, "One twenty-four."

Mark said, "Carry unaffected, still?"

I said, "Right. Add constant zero to B with carry."

Mark said, "Carry."

Bob said, "One twenty-four plus one is one twenty-five."

Mark said, "No carry."

I said, "Store B in location ten."

Bob said, "One twenty-five."

Scott said, "One twenty-five."

Mark said, "Carry unaffected, no carry."

I said, "Load X from location ten."

Scott said, "124."

Barry said, "3."

Karl said, "Man this gets boring."

Mr. Mori said, "It's a good thing CPUs don't get bored, isn't it?"

We all laughed.

Karl grinned. "Well, anyway, X is now 32,003." 

I said, "And we are finally ready to do whatever op-code C was, but it's in indexed mode, and the index byte is zero."

"Yay," Karl said, and we all laughed.

Mr. Mori commented, "I don't see a return instruction."

"Is that what makes code reusable?" Rick asked.

"If your code is constructed correctly," Mr. Mori replied.

"We haven't got that far yet," I apologized.

"That's okay. We'll get there. But this prepares us to talk about the 6502."

Rick asked, "Can we all sit down, then?"

"Sure." 

We all laughed and those of us standing sat down.

 

 

But what if we don't know the base address ahead of time?"

"You're going to tell us about it?"

"Give me a hand drawing this.  

 

 

 

 

 

************* 

Draw a picture of string with constant offset, 

then array in direct page with variable offset, 

then adding the offset to an index variable in memory

6502: 

introduce absolute index on X and Y, instruction limits, and direct page index on X, instruction limits and Y for LD/ST;

Motivate the 16-bit base address problem, introduce simple memory indirect and instructions that use it.

indirect indexed ([base,X] or [offset,X] points to list of addresses)

indexed indirect ([base],Y points to the operand  

absolute indirect jump only

 

***********************

 

 

I found the right section in the stacks just as a library assistant brought Rick over.

"IBM 370," I announced quietly.

"Mainframe," Rick replied, also quietly. He read a spine. "PDP-11." He reached for the DEC manual.

"I think that's a minicomputer."

"So not a microcomputer." His hand paused.

"Mmm." I nodded.

 

Sapphire waiting in classroom? Karl or somebody joking about Joey? Hold it off?

Chapter five, section one dot two, eh, page five dash twelve."

 

"We're going to have to see if we can meet you guys there, then. You think, Cyndy?" 

"Yeah, I think so."

"I get to come along?" Sapphire asserted.

"Saturday?" I suggested. 

 

"Addressing modes, instruction set, pointer operations, branch and jump, looks like it repeats a lot of the information in the Programming manual. Hmm." 

Rick's eyes met mine, but he didn't say anything. He looked back down and continued flipping through the pages. 

I looked back down and continued. "Addition and subtraction routines, multiplication and division, counting." 

I opened to section two and read without a lot of comprehension. 

"Alpha, beta, gamma. Well, I suppose, if it's a small number and fits in an accumulator, adding requires loading the number to be added to, adding the number to add to it, and storing the result."

I moved past the table of contents

 

"Hmm. This looks like an electronic cash register," I muttered as I flipped through the pages of the manual I had. "Instructions on how to use Motorola parts to put together a point-of-sale terminal, including the programs. Complete with bar code reader." 

Rick put the Programming manual down and shifted his chair so he could read over my shoulder. 

 

I kept flipping pages and got part way through chapter 7, and stopped to look at the image at the beginning of section 2, which appeared to be a non-descript box of electronics with very few controls -- only a keylock between a couple of what appeared to be pushbuttons, with three indicator lamps or LEDs above those, on the right side of a front bevel swept back towards the top, with an exaggerated lip along the bottom edge. A large, black, blank faceplate covered an an inset open area to the right of the buttons, extending across maybe three quarters of the front panel.

"EXORciser?" Rick read the section title out loud, and hummed the signature opening phrase from Mike Oldfield's "Tubular Bells".

"For getting the demons out of our designs?" 

We both laughed. 

"Somebody at Motorola must have a sense of humor." He shook his head. "Looks kind of like a squashed toaster oven." 

"No blinking lights?" I turned the page. "Seventeen inches wide, nineteen deep, seven high. Forty-five pounds." I turned the page back.

"The Altair 8800 looks a lot more interesting, with the switches and lights on the front panel."

"I wonder if we could put that kind of front panel on this."  

"I wonder how much it costs, and what you can do with it."

 

 

Which we did when we arrived at the library. 

The librarian took us to the section where the microprocessor books were.

"These are reference works, so we can't let you check them out," she advised us, pointing out the sign of the shelves that said the same thing.

"Thanks." 

 

"Hmm, Intel 8080. IBM 360. Fairchild F8. What's that?" Rick picked up one of the Fairchild manuals and thumbed through it.

"Here we are, Motorola M6800." I picked up one of the Motorola manuals and started thumbing through it.

"Do you need anything more?" the librarian asked.

"Do you know if you'll be getting manuals for other processors?" Rick asked.

She gave Rick a thoughtful look, and said, "Let me check." 

While she went to check, Rick looked at the F8 manual, and I looked at the Motorola manual.

"Wow." Rick muttered. "The F8 looks even more primitive than the 1802." 

We thumbed through the manuals. 

"What have we here?" I muttered. "Source code and engineering diagrams for an example cash register controller."

Rick put the F8 manual down and started looking over my shoulder. "I might be able to make some sense of that," he said.

We continued to peruse the source code for a few minutes, and the librarian returned.

"The electronics technology staff has requisitioned manuals for the, uhm, Western Design Center 6502 and a couple of Texas Instruments microprocessors," she said.

"9900?" Rick asked.

"That's the one," she answered. "Both seem to be really new products."

"That's what we understand," I responded. 

"If you give me your names and phone numbers, we can let you know when we get them."

We did so, and thanked her.

 

 

 

"Oh." Rick put his car in reverse, checked his mirrors and over his shoulder and backed out of the parking space. "I guess that explains it." 

We headed for the college.

"Maybe," he added.

"You don't believe me? You could come to Seminary, you know."

Rick laughed. "Maybe I should. Just to keep an eye on you two."

 

 

The calculus class was on the second floor of Wilkerson Hall, and we passed my dad's office on the way. But Dad was in class, so we didn't see him. 

In the calculus class, Professor White held up a loaf of pumpernickel.

"How are we going to measure the volume of this loaf of brot?" 

Rick raised his hand. "Cut it in slices and measure each slice?"

"You've been reading the text. Good for you."

One of the girls whose name I don't remember suggested, "Or he saw the sliced loaf on your desk."

"Being observant is also good." Professor White lifted the tray of sliced pumpernickel. "Now, how do we measure each slice?"

"Slice up a slice?" I suggested.

"Excellent. Now, could you draw that on the chalkboard?"

 

Professor White explained sums of infinitesimals, inviting us to thing of real-world examples, waxing excited about the elegance of correct solutions, calling correct math sexy.

After class, I suggested, "Hey, I wonder if there's any docs on microprocessors in the library."

Rick looked thoughtful. He said, "We probably do have time to check."

At the library, I headed for the card catalog. Rick asked at the checkout counter. We both ended up in the stacks about the same time.

"Please note," the librarian who helped Rick said, "that this is a reference shelf, and these books cannot be checked out." 

"Got it," I answered, and Rick nodded. 

"Hmm, Intel 8080. IBM 360. Fairchild F8. What's that?" Rick picked up one of the Fairchild manuals and thumbed through it.

"Here we are, Motorola M6800." I picked up one of the Motorola manuals and started thumbing through it.

"Do you need anything more?" the librarian asked.

"Do you know if you'll be getting manuals for other processors?" Rick asked.

She gave Rick a thoughtful look, and said, "Let me check." 

While she went to check, Rick looked at the F8 manual, and I looked at the Motorola manual.

"Wow." Rick muttered. "The F8 looks even more primitive than the 1802." 

We thumbed through the manuals. 

"What have we here?" I muttered. "Source code and engineering diagrams for an example cash register controller."

Rick put the F8 manual down and started looking over my shoulder. "I might be able to make some sense of that," he said.

We continued to peruse the source code for a few minutes, and the librarian returned.

"The electronics technology staff has requisitioned manuals for the, uhm, Western Design Center 6502 and a couple of Texas Instruments microprocessors," she said.

"9900?" Rick asked.

"That's the one," she answered. "Both seem to be really new products."

"That's what we understand," I responded. 

"If you give me your names and phone numbers, we can let you know when we get them."

We did so, and thanked her.

"Are we going to eat lunch?" Rick asked as she returned to the checkout counter.

"I guess we can look at these some more tomorrow," I answered.

We left and got in his car and headed for the Whataburger down the road.

"Onions today?" Rick joked as we pulled into the drive-in.

I chuckled. "Is that relevant?" 

But I did order onions, lettuce, tomato, pickles, and cheese, with ketchup and mayonnaise. Rick ordered a grilled chicken lunch.

We talked about math and electronics while we ate, and then headed for Permian. 

As we pulled into the east student parking lot, Rick said, "Look who's here."

Sapphire was waiting outside the south-east wing entrance. I waved, and she waved back.

"What's up?" I asked, as we approached.

She shook her head. "Just missing you."

I could feel Rick's eyes roll, even though I didn't look to check.

"I'm kind of, I don't know. You're seminary was --"

Rick filled in, "Wild? Cult-like?"

"Hey," I complained.

"Wild, yes. Cult-like, no. Just things I never knew about Moses and Abraham." 

"Maybe I should come to your Seminary to protect Sapphire," Rick suggested.

"Ah, how sweet." She gave him a moue.

"Stop. I'm melting." Rick chuckled.

The electronics classroom/lab was the easternmost room of the south wing, so we talked outside until a few minutes before the bell, and Sapphire hurried for her class.

"You know you're welcome to visit the Seminary class any time."

"I need my beauty sleep."

TOC		Next
Where it starts

Copyright 2025, 2026, Joel Matthew Rees