KIM-1 for me!

I remember doing the noob thing, keying in a short machine-language program from the excellent manuals by Chuck Peddle. It added together two 8-bit values held in zero-page and stored the result back in zero-page. The program worked -- behaved as the manual said it should -- but it was a struggle for me to grasp what had occurred. That's because I had no previous computer background, and elementary concepts such as "address" were new to me.

This was also a time when I was teaching myself about gates, flipflops and so on. The KIM-1 became my canvas! I boosted the RAM from 1K to 5K to 9K, and added a pair of VIA's and a Cheap Video display a la Don Lancaster. The VIA's let me talk to an ASCII keyboard, a paper-tape reader (!) and other delights such as a homebrew programmer for 2716 EPROMs (2 Kbyte capacity)! What a triumph it was to achieve non-volatile storage -- other than audio cassette, I mean. And the video display + ascii keyboard opened the door to FIG Forth -- the object-code for which I had keyed in by hand and stored on cassette (later replaced by a homebrew floppy system).

The poor KIM-1 endured a long series of hacks perpetrated by a beginner, and its appearance became more and more... unconventional! The crowning touch came a while later : a 128K DRAM board which I purchased on the surplus market. Yes, 128K bytes! -- I could scarcely believe it.

To manage this un-dreamt-of expanse, I invented a Don Lancaster-esque scheme that recognized undefined NOP's as prefix instructions. The scheme gave them a time-bomb effect which toggled the state of a newly-minted A16 output, typically just as the CPU reached the data access cycle(s) of the instruction following the prefix. The pre-toggle delay (which you'd specify by selecting among the various NOP instructions) was variable to accommodate faster and slower address modes such as Absolute and (indirect),Y. Typically A16 would invert back to its original state after one cycle, but you could also specify 3 cycles if you wanted to do a Read-Modify-Write. Or, if you intended to JMP, JSR or RTS, there were patterns that didn't return A16 to its original state. The essence of the prefix logic was pretty simple -- just a shift register that'd get loaded with a pattern from a 32-byte lookup ROM. The bits got trotted out of the shift reg at a rate of one per cycle, and every "1" cued an inversion of A16.

Almost by accident, I had begun expanding the 6502 instruction set. I knew those same ideas could be developed further, but the KIM-1 "canvas" was filled to overflowing. I needed a fresh start -- a new computer.

I dubbed the new machine Kim Klone because I liked the corny name and because the new machine and its predecessor both expand the 65xx envelope. But, to avoid implying a broader similarity to the KIM-1, nowadays I just use the moniker "KK Computer."

-- Jeff

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In 1988 my 65C02 got six new registers and 44 new full-speed instructions!
https://laughtonelectronics.com/Arcana/ ... mmary.html

My first Computer was a TRS-80 so I played around with Basic and z80 assembly programming. But within a few years I ended up with an Apple ][ + and moved on to programming in 6502 assembly. For me it just seemed easier and quicker to think like a 6502.

I understood that after a fairly embarrassing initial exposure:

So I was 6 or 7 years old, and we got a VIC-20. Before actually learning what was what, I started typing in all the sample programs from the user's manual, and saw the REM statements stating what the program was doing. Sure, there was all this complex gobbledegook inbetween, but I had no clue what that was for. Thinking I understood enough about what was going on, my first attempt at writing a game in BASIC was a list of 4 or 5 lines of REM statements, roughly describing how the screen should be drawn and what the player should do. Naturally, it didn't do anything when RUN. I learned better after that.

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WFDis Interactive 6502 Disassembler
AcheronVM: A Reconfigurable 16-bit Virtual CPU for the 6502 Microprocessor

The first 8-bit microcomputer I got my hands on (bought it as a kit) was a Z80 Nascom-1. But before I got around to actually use it a new schoolyear started, and the microprocessor lessons were based on AIM-65 which the school had lots of. Somehow they had managed to get a batch of them the same year they came on the market. I started out with the R6500 manuals by Rockwell and later bought "Programming the 6502" by Zaks which I still think is a great book.
Later when I had finished school and military service and got a job one of the first things I was set to do was to write software for a programmed-tracking satellite antenna. That was done on an Apple II clone, and I wrote the code mainly in 6502 assembly but also a bit of UCSD Pascal IIRC. There were other 6502-based projects later. I also came back to the Z80 around that time, some years after my Nascom-1. That was all via CP/M.

-Tor

That's why Transactor magazine was so important. All of the serious technical stuff was there.

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

For me it is (and still is!) the KIM-1.

I still have it, it does work and is original.

Expanded with 32KRAM, serial and parallel I/O, two cassette recorders, 2 MDCR recorders. a Heathkit H14 printer and a selfbuilt 32x20 b/w ascii video display. Published many articles about the KIM-1 in the dutch magazine Radio Bulletin
http://retro.hansotten.nl/index.php?page=radiobulletin.

I sold the other KIMs (still one to go) but will always keep this one!

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http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

The KIM-1 has 40K SRAM, made up of 4 boards with 2K (16x 2102) and 8 with 4k (8x 2114). Eurocard format, 31 pin DIN connectors the BEM/Radio Bulletin bus standard (all cards were designed and published by me and my colleques from the Radio Bulletin magazine).
The power sucked by those IC's is enormous (most ICs were not even LP versions) and the power supplies are simple lineair 7805 based, so lots of heat to loose. It worked well, the machine never got very hot.
It has two serial interfaces (6850) and two PIA/VIA boards, total of 4.

The first computer I encountered was a small mini-computer at a local high-school about 1969/1970. I thought it was one of the coolest machines I'd ever seen. (I was about five).

The first computer I spent a lot of time at was a Commodore PET at high-school. The first computer I "owned" was a VIC20, the first computer I bought myself was an IBM clone. I first got into assembly language programming about 1980 trying to get better performance out of the PET. With the VIC20 I built my own 256k dynamic RAM expansion unit. It was bank switched with the VIC able to access 32k at a time.

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http://www.finitron.ca

For me , I started on the Netronics ELF II at age 14. I soldered it up and was like a new Dad when I powered it up the first time. It only had 256 bytes of RAM, and a 256 byte ROM, but I spent hours entering hex opcoded into that thing and learning assembly programming. I had a cassette tape to save and restore programs.

I then moved up to an Apple II at school and played with BASIC and assembly. By my senior year, I was teaching our teacher assembly.

I purchase a C-64 and used it in college and took it with me when I went in the Air Force. It wasn't until 1989 that I bought my first PC clone.

I still have the 18xx chips from that ELF. Someday, I may rebuild it, just for kicks!

Daryl

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Please visit my website -> https://sbc.rictor.org/

Great stories everyone! This page from July 1984 (indexed here) has a lot of parallels with my own story: I got into electronics by reading the monthly magazine Practical Electronics, and distinctly remember a Master Mind (cows and bulls) game in TTL one month followed closely by a microprocessor version in a later issue. The micro - might have been the CHAMP based on SC/MP - was much the simpler design and yet a very general system. So I kept my eye on the adverts for the various NASCOM and Mk14 and AIM65 products (I may have my chronology wrong here) and loitered around any computer shops which I could find and even went so far as to hire a PET for a single day by clubbing together with a couple of friends. That was a silly idea! We couldn't realistically stay up all night, we had no plan as to what to do, and the fumes from the coal fire got to me too. You need oxygen to program.



But my first owned machine was a Compukit UK101 - a single-board 6502-based kit, pretty much an Ohio Superboard clone - apparently came out in '79. Also my first real soldering experience - I had to solder it twice, but it did then work. Cassette storage, of course, and display with a UHF modulator to one of a series of refurbished ex-rental monochrome televisions. Probably quite the fire risk, and of course my PSU construction didn't feature any insulation. I would have bought my Zaks book at that time.

.
Slideshow here - this was the second case, the first being a diagonally sawed-off drawer from home with a plexiglass cover. I'm sure I didn't ask for permission to saw that drawer.

(I'd already been fascinated by computers for some time: I'd lapped up one or two books - one of the first being the How and Why Wonder Book of The Computer and another being Alan Wilkinson's homebrew CPU book mentioned in this thread.)

I had had access to a local university computer (an ICL? don't know) via a link from school, and also a weekly card deck shuttle - but that was BASIC, so no CPU exposure. I'd also gone through quite a number of calculators, sometimes taking advantage of no-quibble money-back guarantees (Sinclair Programmable was one - one memory and just 36 keystroke program capacity) but I was out-manouevred by one salesman and actually bought a TI-57, my first programmable calculator. Much less capable than Garth's but the same general architecture. I think it had just 50 steps, and no storage peripheral or even non-volatile memory. The TI-59 was the top-line model but much too expensive.

A few years after the Compukit I got a BBC Micro - probably 1982 - an excellent hardware and software architecture, if a little low on RAM by C64 standards. I think that was mostly funded from excess cash from my student grant - those were the days, but as I don't drink I had a lot of beer money left over. (The Compukit was funded from paper round, pocket money, birthday and Christmas money and, I think, a parental subsidy.)

The Beeb of course has a two-pass assembler built into the BASIC, whereas the Compukit had only a one-line monitor to offer. So that was a much more comfortable machine to work with, even still with only cassette tape, until eventually I bought a (double density!) disk interface and dual drive. I bought a RAM disk at some point too, or a sideways RAM expansion as it was known.

At Uni there was a short course using a 6800 dev board - very disorientating to have two accumulators and a single but wide index register.

At some point I got interested enough in the idea of the Archimedes (and the ARM) to buy the manuals for the machine and the book on assembly language programming the ARM, but the machine itself remained priced out of reach.

After that I went for Amiga rather than Atari, and eventually got a 16Mbyte P75 PC when I heard about Linux - although we also ran Windows on it for some particular purpose. That was in '95. Since when it's been mostly x86, and no assembly for me, until emulators popped up and ARM dev kits became cheap. I did once patch a byte or two of an x86 binary, and I once did a course on 8051, but mostly I've remained a 6er not an 8er.

Here's my Beeb, or maybe not mine, from our 65816 upgrade adventures of 2009.

Oh, I should mention my Transputer accumulation! I did a course on that around '89, and indeed worked at Inmos for some time, but no assembly.

Cheers
Ed

[Edit: fix broken links]

Au contraire! The program did do something when you ran it. It quietly said to itself "Who's the dummy that wrote this program?"

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

Cool! It looks like it never lacked for use.

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

Home made computers look so wonderful! I'll post some pics later of my Orwell machine which is migrating from breadboard to Veroboard to, eventually, PCB. My construction technique are equally as, err rustic, shall we say!

My first machine was a Vic20 I got when I was 10. Before getting it I remember reading every 80s Usborne computer book I could get my hands on and I was writing my own little Basic programs before I even got the machine. I am now recollecting all those books by the way and reviewing them using my Orwell computer. That's its purpose I guess. Been meaning to post a link to them here: http://www.asciimation.co.nz/bb/category/usborne I am sure others here remember those books as fondly as I do.

I then moved on to an Apple 2+ shortly replaced by a 2e my father was able to get with an educators discount. I recently found the original receipt and it was a lot of money when he bought it for me back in 86. I never really appreciated how much. It paid off though as computers have done me well career wise since. From there I went to Amigas which proved handy when I was at Uni where they used Macs and I was able to run an emulator on the Amiga at home. From there I went to PCs (which I am still on now).

I didn't really get into assembly language until much later when I started playing with PIC microcontrollers. My first 6502 assembler was only fairly recently when I build my beer brewing Bender and of course had to build him a functional 6502 brain. Basically a cut down version of a 1541 Commodore drive for hardware and some (very) simple software to play audio samples.

Orwell was the desire to build a complete 6502 machine with BASIC that could actually be useful for something. I still find it amazing though that now I can build a machine myself that is basically equivalent to the machine I started with 30 years ago and understand exactly how it all works. Back then it was all such a mystery!

Simon

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My 6502 related blog: http://www.asciimation.co.nz/bb/category/6502-computer

I wanted to see Bender, but he's not immediately obvious when you follow the link Simon provided. However, in Simon's "About" section there is a link to several other links, including Bender. Apparently the About section is for "projects and hobbies that don’t quite deserve their own page on my main site."

You're too modest, Simon. Bender is magnificent!

-- Jeff

_________________
In 1988 my 65C02 got six new registers and 44 new full-speed instructions!
https://laughtonelectronics.com/Arcana/ ... mmary.html