Getting the KIM-1 to talk to my Mac
6 comments
·July 25, 2025JKCalhoun
reaperducer
Before anyone runs out and buys a modern-day KIM-1, be sure you know what you're getting.
I got one based on an Arduino (also hooked up to my Mac), and it's more of a simulator than a re-creation. It works fine if you want to play MicroChess and a few little loops and subroutine things in the assembler, but once you get beyond what's in the PDF you find out quickly that you're in a sandbox.
tonyarkles
Huh, that record format on the paper tape is almost identical to the Intel Hex format that still unfortunately gets used a bunch in embedded systems. All it's missing is a 1-byte "record type" field and it uses ";" instead of ":".
Also while confirming that I discovered that the Intel Hex format was standardized in 1973... so right around the same time as this KIM-1.
criddell
This is really cool.
My first computer was a TI-99/4a but the computer I really wanted was an Atari 800. Years later I finally got an Atari, an Atari ST, and I loved that machine.
So many times I've had eBay open with some vintage computer on the screen and my mouse hovering over buy-it-now, but I just can't do it. Most recently it was a TI-99/4a with a fully loaded peripheral expansion box that I couldn't afford in 1983.
I'm not into retro gaming (they are unforgiving and often not very fun) and I can't think of anything else to do with it. I've thought about some basic home automation tasks, but these old machines draw so much power it feels bad. So I know it would become décor (or as my grandmother would say - just another damned thing to dust. She wasn't into tchotchkes).
I sometimes think about how wonderful it would have been if Atari, and Be, and Amiga, and all the other 80s machines had survived and we had a diverse market of computing ideas. I suspect though that the end would have been the same. The Electron people would have showed up and paved over everything unique and interesting in each of these machines.
flyinghamster
> I'm not into retro gaming (they are unforgiving and often not very fun) and I can't think of anything else to do with it. I've thought about some basic home automation tasks, but these old machines draw so much power it feels bad.
That's what dissuaded me from ever attempting to resurrect overly-old hardware, although at least a KIM-1 isn't going to be a power hog. On the other hand, something like a PDP-11/70 would suck down a ridiculous amount of juice for much less computing power than a modern microcontroller.
Then there's the whole parts problem. Tracking down boards and components that will never be made again is another nightmare. Emulators make far more sense when you don't want to be your own component-level repair tech.
alnwlsn
Then there are the lonely few of us who get the most enjoyment from being your own component-level repair tech.
Yeah, I don't know why either.
If you wanted to play around with retro hardware the KIM-1 is a fine machine. Actual KIM-1's go for $1K or so on eBay, but fortunately there are a few clone kits out there. For the most part too they use the same chip set as the original.
I have both the PAL-1 [1] and PAL-2 [2] kits and enjoy them both. (For the price difference, I would recommend the PAL-1 if you are just wanting to play around with a retro 6502 computer.)
There are even online KIM-1 emulators if you can figure them out [3][4].
The best jumping off point though is probably Hans' report computer pages [5].
[1] https://www.tindie.com/products/kim1/pal-1-a-mos-6502-powere...
[2] https://www.tindie.com/products/kim1/pal-2-a-mos-6502-powere...
[3] https://maksimkorzh.github.io/KIM-1/
[4] https://maksimkorzh.github.io/KIM-1/
[5] http://retro.hansotten.nl/6502-sbc/kim-1-manuals-and-softwar...