BDC-6500: ROMs and other information gathered from a customized KIM-1
I purchased this customized KIM-1 computer from an estate sale, and have since been documenting it and trying to get it working again.
In the handmade enclosure, I found a Rev D KIM-1, a 16K memory board, an 8K "Visable memory" board, and finally a hand-wired ROM board. The 4 1k ROMs were labelled KVOS.
The only documentation I've found of KVOS is a single ad announcing its availability as a 6502 OS available from CGRS Microtech, in the December 1978 issue of Popular Electronics: http://www.classiccmp.org/cini/pdf/pe/1978/PE1978-Dec-pg90.pdf#page=2
I was able to dump the ROMs with a handmade board (see https://github.com/option8/ROMbie) though the dumps seem to be corrupted in places. I'm not sure yet if it's the ROMs themselves or the reader.
update: The latest dumps from my rebuilt reader are cleaner and more consistent. Any weirdness that remains is likely in the ROM itself, and not a result of a bad read.
This repo is to document the disassembly of the ROMs and other findings as I get deeper into rehabbing the original BDC-6500.
I'm using da65 with the info.txt file in the main directory. Since the ROMs seem to be corrupted, I've made some modifications to the complete dump, in the file F000-FFFF-combined-modified.rom. The original dump can be found, unmodified, as well. As I update my reader, I will replace the dumps, if they end up being cleaner.
Photos of the enclosure, boards and wiring here: http://retroconnector.com/bdc-6500-computer-kim-1/
I've recreated the KVOS font from the character section of the ROM. Bitmaps of the full ASCII set are in the "Character ROM" directory.
A quick presentation on my findings and the background on KVOS, presented at KansasFest 2017, is available here: https://archive.org/details/2017_Kfest_Disassembling_KVOS