Chapter 11.8: Headwinds -- Becalmed
Chapter 12: Storms
Friday morning, when I got to the electronics lab, I gave Dr. Brown my extra 68705s from the rail I had from Denny, and that made enough for all the students in the project group to get started working on 68705 projects.
Some of the group were in the lab doing so as soon as the morning lab sections were finished.
I had a BASIC project that the Micro Chroma 68's disk drives were not ready for, so I had to go to the keypunch lab. Mike was there when I arrived, working on code at a desk. I had code ready, so I took the open keypunch and punched about fifteen cards, then went to a desk to merge them into my program deck.
Mike took the keypunch after me.
I took my deck of punched cards to the computer room for a test run. Professor Bright's sister-in-law, Sherry, was the operator on duty, and she took my deck.
While I was waiting for my results, Mike came to the computer room dutch door and submitted his deck. He leaned back against the wall beside me in the hall outside the door to wait.
"So you're dating Julia."
"Well, ... I guess Julia and I are dating."
He chewed on that for a minute.
"I don't get it. She was never interested in computers or electronics when we ... back in high school."
I digested this information. "Interests change. Maybe she's seeing more of her dad's line of work."
"Maybe. He sure tried hard enough to get her interested."
More silence.
"How did you two end up getting together?"
I laughed. "Who can say? I mean, she took classes from my dad, and then she started doing some work for him. We first met in his office."
"Your dad seems to be a target for college sophomore crushes."
"True. He does. Lots of people seem to like my dad. And I seem to have been a target for transference in this case, not that that explains anything. She's been aware for some time that I'm not exactly a younger version of my dad."
The operator brought my results to the door, and I accepted my deck and the printout.
"Sorry," she said. "Had to cut off the printout after four pages."
Mike laughed.
"Yeah, that wasn't supposed to happen. Sorry. Thanks."
"Wrong variable in the loop controls?" Mike suggested.
"Possibly. I'd better get a desk and sit down with the program listing."
We nodded politely, and I returned to the keypunch lab. I was marking my listing with expected values at different flow points when Mike returned, laughing.
"Index range fault. No printout at all." He waved his listing at me and put it down on the desk next to the one I was using, and read my listing over my shoulder.
"What are you doing that for?" He pointed at a line.
"It's the way I'm handling the loop variables. How are you handling them?"
He spread his listing out on his desk and pointed at several lines. "Yeah, it's not well-structured, but it should work."
We compared notes and found places to add debugging prints to our programs. Both keypunches were open, so we quickly got our debugging cards punched up and took the decks back to the computer room.
"Debug prints, so shut it down after two pages, please." I handed my deck to the operator.
"I should be so lucky, but I have debug prints, too." Mike handed his deck to her, too.
"Gotcha." She took our decks and put them in the queue.
"She couldn't deal with my questions about the Bible, but she sure seems to have no issues with you being a Mormon."
"Should she?"
"Don't you guys have some sort of rules about not dating non-Mormons?"
"It can earn one a little social censure, and church leaders recommend against it, but, no, no specific rules against it."
Mike frowned, and thought a bit.
"Well, I suppose Baptists don't have any specific rules, either, but she's facing a lot of that social censure for your sake."
"Social censure is not a particularly useful basis for decision making. But we have been discussing religion."
The operator came to the door with our results, and we took them back to the keypunch lab.
"Dang, with the debugging prints in, I'm getting results."
"Ah. I see where my loop variables are getting skipped." I marked several lines for edits. "Constructed conditional getting jumped into."
"Huh?"
I showed Mike the GOTO command in question and the constructed conditional, using a pencil to mark the intended structure in pseudocode.
"Ah. Maybe I should be a bit more rigorous with my structurization." He penciled pseudocode into his program listing while I punched up a few more cards and swapped them into my program deck.
"Let's see what this does."
I took my deck to the computer room while he punched cards for his changes.
He came almost right behind me with his edited deck. "Yeah. Let's see some results." And he handed his deck to the operator before leaning against the wall across from me.
"Okay, so you've been talking about the differences in religion."
"So far, we're finding more in common than not."
"But you don't even worship the same God."
"Really?" I gave him a deliberately quizzical look.
"Mormon is not Jesus."
"Mormon did not claim to be Jesus. And he strongly recommended Jesus to anyone who read his book."
"Huh?"
"Would you like to read some of what he says on the subject?"
"That Golden Bible you guys use?"
"Golden?" I raised my eyebrows. "Many of buy our scriptures with gilt-edged pages, to make it harder for moths to start eating them. But other Christians do that, too. I opted for cheaper, myself. But Mormon didn't write in the Bible."
Mike looked at me suspiciously.
I grinned. "Sorry. I probably shouldn't be so elliptical."
"I don't mean to interrupt, but I have both your listings."
"Ah. Thanks."
She handed Mike his listing, and then handed me mine
"Uhm, yeah. Thanks."
The computer operator came to the door with our listings, we took them back to the keypunch room, to examine.
"So, how do you like the way she kisses?"
I looked over at Mike, and he met my gaze, defiantly, at first, then slightly embarrassed.
"She didn't tell you?"
"I asked her to tell me when she was ready."
"Huh?"
"I could see the lack of current chemistry between you two."
"You don't seem bothered."
I was in the keypunch lab until lunch.
When I got there, the five in the microprocessors class had already breadboarded test circuits and were working on test programs. Jeff and Mark were helping them figure out the 6805 instruction set when I got there.
"Man, the 6805 instruction set is a revelation!"
While I was watching them work out how to
Mark and Jeff were in a small group which was already
Most of the students had the necessary parts in their lab kits, even without a run to Radio Shack the evening before (which several had made.. And most were doing initial were
Many of the students had already bought perfboards and other necessary parts. Some were using breadboards instead of perfboards, so it would be easier to fix their circuits if they didn't work as well as they wanted. And they got together in the lab Friday afternoon to wire them up.
I showed the other students my ideas for possibly adding ROM, RAM, and DMA on the daughterboard for the Micro Chromas.
Bob shook his head. "You're trying to put the whole computer on the daughterboard."
Mark looked at my doodling thoughtfully. "The DMA looks interesting. I think I'll leave space on the daughterboard for it."
, but no one was especially interested in exploring new territory at this point.
No one, that is, except Mike, who was already trying to design his daughterboard to have room for a 68008 coprocessor. I refrained from discouraging him for reasons I couldn't really put a finger on. But the idea got caught in my head, and I made room on my mental back burners for a project to make a 68000 coprocessor for the Micro Chroma.
Julia and I made a run to the parts store on West County Road for parts, and Suzanne and Winston caught a ride with us.
While we were there, I asked about floppy drives and keyboards, and they gave us some catalog pages.
We also dropped by the surplus shop to see if they had keyboards, and Julia found a raw keyboard she liked. I picked up an identical one, figuring I'd need it, and Suzanne grabbed the remaining one of the same type.
Winston picked up a keyboard that looked similar and showed it to me.
"Would this one work?"
I looked it over. "It has a controller chip that I don't recognize. Probably a microcontroller, and it looks like it produces serial output."
"Is that good or bad?"
"The Micro Chroma 68 wants parallel."
"Instead of serial, so it's not good."
"If we knew what the serial bits look like, we could probably use the 68705 to convert them to parallel."
"Seems like a waste of processor power."
"Depends on how badly you want this particular keyboard and how much you figure the time to rip the current CPU and keyboard matrix out is going to be worth."
"And whether I want to waste the extra power from the power supply."
"True, but it probably wouldn't be all that much."
I looked the keyboard over a bit more and asked the proprietor. "Do you have any documentation for this?"
He shrugged. "Don' know anythin' about 'em. You'll be on yer own. But I'll give it ta ya cheap."
I looked it over some more, then handed the undecoded keyboard to Winston. "Tell you what, Winston, you buy this raw keyboard and I'll see what I can do with this one."
He initially declined, but I urged him to take it and he did.
I turned back to the shop owner. "We have about twenty more students working on similar projects, and many of them'll be wantin' keypads and keyboards, too."
"That 'splains all the interest I've seen in keypads. Should be gettin' more keyboards in next week."
"Do you ever get floppy drives in?
"Never have yet. But there's always a first for ev'rythin'."
We talked a bit about the kinds of hardware the students in our project would be looking for before we headed back to the lab.
When we got back, Dr. Brown said we could keep working until dinnertime, so I could go home and take care of my newspapers and come back. Julia decided she'd stay and keep working on her board.
Before heading home for the newspapers, I spent an hour with Mark and Jeff working out more details on the daughterboard, and we were able to get their boards booting up to the TV-BUG monitor prompt.
When I got back from delivering the papers, Bob and Julia also had their boards booting to the TV-BUG prompt, and Julia had started making a clean copy of my rough diagram of the daughterboard.
Mark, Jeff, and Bob were helping other students instead of working on their keyboard decoders, and many of the students had their trainers sequencing the LED segments already.
"Well, Dr. Brown," I asked, "should I help the students who are stuck, or should I get started walking everybody through writing a keyboard decoder?"
"What's the goal?"
"Theirs or mine?"
"Now there's a good question."
So I put it to the other students. "Who wants to get a look at how to write a keyboard scanner now?"
Jeff responded immediately, "I want to try my own hand at it."
Mark nodded in agreement.
Bob added, "The daughterboard was your baby. Let us have some fun here." I looked around the room. Nobody else seemed to be anxious to offer a different opinion.
"Oh-kay. I guess Julia and I will write our own."
"Of course," said Mike, with a smirk. "And you'll show us how all about how you did it next week."
That got some chuckles from the class.
So I spent the remainder of the afternoon helping get everyone's trainers working enough to sequence LED segments. And Julia spent the time puzzling through the 6801 and 6805 datasheets. Winston and Suzanne were able to get their boards up to the TV-BUG prompt, as well.
The lab session slowed down, and students began packing up and leaving.
When the last trainer was sequencing, I stood up and moved back to sit beside Julia. Jeff and Mark were working on their keyboard decode circuits. Pat and George came over.
"You two will be working on this stuff together tomorrow, right?"
I looked around and saw Mike look up.
"I think so," I said, and looked back at Julia.
"I would be disappointed if you had other plans," she huffed in mock offense. "I'm very curious about those packages you got Thursday."
"Packages?" George asked.
"Flex and FORTH. Yeah. I guess we will be."
"Can we come over and work on our stuff, too?" Pat asked
Out of the corner of my eye, I could see Mike was still watching.
"Sure." I thought I saw a frown flicker across Mike's face.
I turned to George and asked, quietly, "Does Mike need an invite, too?"
I saw a look of concern flicker across reflected in George's eyes, and I felt, more than heard, Julia draw a quick breath and I turned to look at her. I sense a veil in her eyes.
"Mm," George hesitated. "Maybe we should talk this over first."
"He's a friend isn't he?"
George didn't respond.
Pat drew a deep breath, as well. "Yeah, he's a friend."
"Not a good suggestion?" I looked inquiringly into Julia's eyes, but she continued to hold me off.
"It's okay, I won't ... I don't mind."
"I'll leave it to you guys," I turned back to Pat and George.
*****
The road home was uncomfortably silent, and Julia kept her thoughts to herself.
"Are you going to stay for dinner with us?" I turned down 27th Street.
She didn't look at me. "Should I?"
"I'd like to have you around tonight, if you don't mind that I'll be down the rabbit hole again."
"The TI processors?"
I turned up Muskingum. "Yeah. Need to get some reading done on those. And I'll also be trying to figure out how to adapt Flex to my disk controllers while I give those drives a workout. Writing the exerciser routines is going to be pretty esoteric stuff. But it helps if you're there to listen."
She smiled a sad, slightly ironic smile. "You're going to be a hard man to live with. It's hard to keep up with you."
I did a rolling stop at the Polyantha Park intersection at 31st Street, since there was no traffic.
"Tell me about Mike sometime?"
She turned to face the window and leaned across the gap between the bucket seats against my shoulder. Working the transmission didn't leave an arm free to wrap around her shoulder because we were in the back streets, but we were already approaching 36th Street. So I leaned my head against hers and satisfied myself with that for the last two streets home.
*****
Julia ate dinner with us, and then she dug out her homework, and I dug out mine, and we sat together on the living room couch to work. I set up my computer on the magazine table, and we took turns using Tiny BASIC as a calculator and using the text editor.
"Magazine table?"
"Tea table, coffee table, same thing. No tea or coffee in our house. Sometimes we emphasize that fact by calling the coffee table a magazine table."
Julia laughed quietly.
Dad and Giselle were taking turns with Giselle's computer in her room, and Mom was busy getting an early start on the taxes.
When I finished my homework, I read through the datasheets and other information on the 9900 and 9940 that I had received from Jayne and Dave.
"Now where is that?" I thumbed through a datasheet.
"Where is what?"
"The description of the instruction to call a subroutine. I found the return instruction, but not the call, and I want to get a look at it."
Julia gave me a blank look.
"It's actually a full context switch on this processor."
She raised her hands with a smile that said, "I have no idea what you are talking about."
I grinned back. "Just pretend like your listening to something that makes sense."
"Hah."
"I'm going to pretend I'm explaining it to you, but I'm explaining it to myself."
"Uh, huh." She snickered.
"The TMS 9900 has a really unusual register scheme. All the computational registers are actually in memory, pointed to by the working set register."
"I was lost when you said scheme. Or register."
"Registers are where the calculations occur, and RAM is where you store results, and the 9900 uses RAM for registers. It calls the RAM it uses the working set."
"I can pretend I might understand that someday."
We both laughed. "Thank you. Now you have to know where your registers are, so the 9900 has one real register that points to the working set. It's called WP."
"Working set pointer?"
"Careful. You might actually understand this."
"Hah."
"You also have to know where the instructions are, so the 9900 has a register for that. It's called IP."
"Instruction pointer."
"Nice. Anyway, when you call a new procedure or routine, you usually want to know how to get back to where you were."
"I could see that."
"So the 9900's call instruction holds onto the old IP and WP, loads a new WP to point to a new working set, and stores the old ones in the top of the new working set."
Julia frowned. "You know that almost makes sense."
"It does. I haven't mentioned the status register. I think it's the status register. But it saves that, too."
"Now I'm lost again."
"That's okay. I want to see how the new WP is specified, so I'm looking for the instruction, and I can't find it. I can find the return, but not the call. It's called BLWP, for branch and link WP."
I thumbed through the datasheet pages again, with Julia looking over my shoulder.
"These are jumps?" She said.
"Yeah. Conditional jumps. It's not there."
I thumbed back and forth a bit more.
"Single operand instructions. How many operands does this branch and link, uhm, WP instruction have?"
"That's actually what I want to find out."
"B for branch."
"Yeah."
"BL."
"Branch and link, but without WP."
"BLWP," we said in unison.
"Op code 17."
"Where? I don't see seventeen."
"Binary." I pointed to it. "One zero zero zero one."
"I'll take your word for it."
I gave her a sideways hug.
Julia continued watching me.
"What?"
"So you found it. When are you going to look in those packages. I'm interested in those packages."
"Packages. Heh." I went into my room and brought out the two thick envelopes that had come the day before. "Which is most interesting?" I raised my eyebrows and sat back down.
"She gave me a sly grin. "I'm going to say disk operating system, and you're going to make me wait."
"Now why would I do that? Flex is the TSC package. Why don't you open that, and I'll open the Mountain View package."
The energy dropped from her shoulders. "What will I know by opening them?"
I grinned, "More than if you don't." I picked up the TSC envelope and handed it to her. She looked at it curiously, then proceeded to open it while I opened the other.
The Mountain View Press envelope had two thick photocopied manuals, about two hundred pages total, and a cassette. One manual, with a kind of baby blue cover, was titled, APPLE II fig-FORTH INSTALLATION MANUAL AND ASSEMBLY SOURCE LISTING WITH GLOSSARY, and the other was the baby-pink covered fig-FORTH FOR 6800 ASSEMBLY SOURCE LISTING. The cassette was labeled fig-FORTH FOR 6800 ASSEMBLY SOURCE.
Julia held four diskettes and several photocopied manuals out to me. "Like I say," she said with a lopsided smile. "They don't look very interesting, and I suppose they won't run tonight."
The diskettes were the FLEX Operating System itself, a diskette of utilities, and the Pascal and C compilers. The manuals were user's manuals for each of the compilers and for the operating system, and one labelled "Installation Hints". The former three manuals were a bit more nicely produced than the Forth Interest Group manuals.
"That's probably true about anything running tonight."
"Can I claim my first kiss from you?"
All the energy drained out of me and I wrapped my arms around her and gave her a hug. As my energy returned, I nuzzled her neck gently before drawing back to search for her lips with mine. For someone who had no idea what he was doing, it sure came naturally.
"Ahem." Giselle's voice broke through the fog. "Sorry to interrupt, but I need some help."
We both drew back.
"Thank's 'Zelle," Julia said quietly, with a shy smile, without breaking eye contact with me.
"Uh, uhm, I'm sorry. I, erm, didn't mean to interrupt."
"Nah. It's okay. I think." I'm not sure what my expression looked like.
Julia blinked first. Maybe. Then we leaned against each other, our foreheads touching, and she whispered. "Thank heavens. That was a lot of passion in a kiss. You'd better help her."
We both went into Giselle's room and helped work out some problem she was having with a saved file that she couldn't get to read back in, then went back to the living room.
(Just as a reminder, Julia, in this story, is a composite of several of the important women in my life from when I was single. Yes, that first kiss comes about five years earlier than for the real me.)
That was an experiment we didn't dare repeat that night, nor for some time after.
Instead, Julia listened patiently while I explained the program I needed to write, to generate generate a lot of pseudo-random data that would exercise the dark corners of my controller. Since the data produced by the program was deterministic, but with a distribution of values that resembled theoretical randomness, it could be recreated in the read pass, allowing me to test several times that what was written was the same as what the controller read back, without having to have a known good controller and a known good disk to compare with.
The program was done by the time I finished explaining it.
Then I borrowed Giselle's computer just long enough to write the initial read test disk on the CoCo. That took about ten minutes, and Giselle and Julia and Dad and Mom chatted in the kitchen while I worked.
I got the Micro Chroma 68 set up to read and check what it read in an endless cycle, counting the number of errors. I set it up to retry on errors, and to count the number of retries, and the number of times a retry did not get a good read.
With the exerciser routine started, we had a little scripture study, chasing down the concept of stewardship relative to revelation and commandments.
Then I drove Julia home. And we kissed each other on the cheeks, because we didn't want to risk anything more.
*****
When I got back, I worked out a program to test both reads and writes.
I stopped the read tests after the hundredth full-disk pass and checked the counts. There were seven errors, none of them recurring, a number compatible with the amount of dust in the air.
Before I went to bed, I got it started on the read/write tests.
In the morning, after delivering the newspapers, I checked the error count and found the results similar to those for the read passes. Julia came over soon after.
"So how much remains to do before Flex runs?"
I held up the porting hints manual and we started reading through it.
I worked out the disk I/O, keyboard input, and display output routines, and Julia pretended to understand my explanations, working on homework when I was deep down the rabbit hole.
The morning sun was on my back when I rang the doorbell and Mrs. Cisneros let me in.
"Kind of early, isn't it? Wouldn't it have been less hassle for Julia to have just slept over in your sister's room?"
"Mom. Behave yourself."
I wasn't quite sure how to respond. I understood that she was giving me her approval in a sort of back-handed way, but I knew that neither Julia nor I were ready for that kind of pressure.
It had been two weeks since the visit from the corporate contingents, and
Even news of the shuttle test failure
Wedding announcement from Satomi and Teruo Fukumasa.
Idea to travel to Japan.
targets:
Motorola tries to squelch the 2800 and 3800 discussion, esp. with TI, but I mention 25 students who are moving and shaking, who will be upset at Motorola if Motorola comes down on them.
Add concept that registers are working set cache to discussion to initial discussion of 2800.
communication with Motorola about advanced 8-bit CPUs, 2801 and 3801, also 2809 and 3809, 21609 and 31609.
communication with TI about splitting and caching the 9900's stack
Mike's 68008 is interesting to IBM. Help Mike do it with 68000 instead, since 68008 is still coming.
spring break -- when is it? article on Micro Chroma 68+daughterboard, Julia and Joe write it. Series planned.
Meeting with Mr. Wells and Megabyte to discuss my safety -- plot to have megabyte turn me, she doesn't want to split Julia and me up, Julia and Mike, me apparently sidetracked in segmented 8 and 16 bit archs.-- With Megan out to do something, Wells asks me to promise not to divulge, tells me about 8088 skunkworks project, false competition with 68000 blocked with the excuse that it would compete with their system 32/4/6/8, but real reason is that there is a group that does not want the real power of computers in the hands of the common person.
Forth as library, 6801, 6809, 9900, 8080, Z-80, 8086, 68000, etc.
Motorola's 2801 and 3801 as SOC cores with MUL and I/FDIV (integer whole/fractional divide); optional 6829 style MMUs integrated with eight bits of address extension: code, direct, extended, user/sys data, user/sys stack, extra segment; optional 6844 style DMACs, etc. 2809 as corrected 6809 (direct page, repeat prefix, bit mul/div primitives, 24-bit segment/limit registers) and SOC core. 31609 as 16/32 bit version of 6809 model. 68008 canceled. Revised 68K model without complex 68020 instructions.
Common OS
Jeff & Mark's Micro Chroma 68+6809
Mike's Micro Chroma 68+68000 using external multiplexor instead of 68008.
TI makes improved dev tools, docs, plans 9941 as 64 pin 9940 with 512 bytes of fast internal RAM and ROM/EPROM, capable of separating register space from general space.
TI also plans series with split stack and implicit register cache.
Micro Chroma 6801, Micro Chroma 6809, Micro Chroma 68001/6845
Disk controllers -- WD versions and 6801 versions, 6801 versions with buffering and (eventually) higher-level stuff
IBM adopts Common OS for PC future OS.
TSC and Digital Research pick up Common OS for their future directions.
Is trip to Japan for Mike and Julia's honeymoon? Or group vacation?
Chapter 13: what?
[Backed up at https://joel-rees-economics.blogspot.com/2020/05/bk-33209-storms.html.]
