MOS KIM-1 Reproduction – Retro Computing

Dave Williams designed, build and sells MOS KIM-1 Reproduction boards. A real KIM-1 clone! The goal was to reproduce a KIM-1 as exact as possible.

So the MOS KIM-1 Reproduction board has the same dimensions, same connectors and as much as possible the same components, including the audio cassette interface, 1K RAM with 8 2102 RTAM ICs. The keyboard is reproduced with the same layout and looks and feels quite identical. Components types are chosen close the the originals (though the KIM-1s went to many revisions with varying looking components) and placed on the same location. The CPU is of course a 6502 at 1 MHz crystal clock frequency. The edge (Application and expansion) connectors are physically and logical identical.

Since 6530 RRIOT ICs (the 002 and 003 variant) are not available anymore, the same solution as in the other clones is chosen: a 6532 RIOT with a 2K EEPROM and some logic ICs (3) to get a hardware solution that makes it look exactly the same for the KIM-1 ROM software. The PCB is a new design, not the typical 70ties curved PCB lines hand layout design.

The result is great: it feels, looks and operates as an original KIM-1. First Book of KIM programs run, MICROCHESS runs. Even Microsoft KIM-1 Basic run, when additional RAM is connected.

I now (Januari 2023) have two of the MOS KIM-1 Reproduction boards. Dave Williams did a new version, with a white PCB. And the new I/O card has a TTY swicth and a serial DB-9 connector (with a MAX3232 interface, so true RS232 levels).

Documents (thanks to Dave Williams!) to download

	MOS KIM-1 Reproduction Board Layout
	MOS KIM-1 Reproduction Schematic
	MOS KIM-1 Reproduction BOM

I added the Corsham Technologies KIM-1 60K RAM/ROM board and the KIM I/O board, which makes it a great system!

With the MOS KIM-1 Reproduction comes a small edge connector PCB for audio and power connections. Alas no TTY connections and keyboard/TTY switch. On an USB stick the well known KIM-1 documentation (all also found on this site!) and the First Book of KIM programs, as typed in by Jeff Tranter in papertape format, also found here. But as extra the programs as KIM-1 audio files are provided, as WAV files, ready to load into the KIM-1.




MOS KIM-1 Reproduction	Original KIM-1 rev F
MOS KIM-1 Reproduction	Original KIM-1 rev F

Some photos from Dave Williams, showing the KIM-1 Reproduction connected to an audio cassette recorder, a KIM-1 S-100 Motherboard with a RAM card, running Microsoft Basic KB9 and a production line of KIM-1 Reproduction (with a real KIM-1 in the top row!)