With a scan of manuals by Gerben Voort, and a third photo of a cassette with KB-9, time to refresh the KB-9 pages.

Thanks Gerben Voort

The KIM-1 monitor surprises me every time I dive into it.
The KIM-1 Explained is nearing completion. The KIM-1 explained

There is a bug in the TTY CLI, it accepts characters as ‘;’ and ‘:’ as valid hex and translates to A..F.

KIM
0200 A9 ;;
00BB 00 ::
00AA 00 ????
FFFF 1C

More about this innocent feature here: PRTBYT, GETBYT and PACK

The hardware and the software in the KIM-1 work closely together. The tiny program, less than 2KB in the two ROMs, together with the simple hardware, is very clever designed.
The KIM-1 is a complete computer with two user interfaces and data storage with a simple namespace. It is one of the first 6502 computers, and many clones or derived 6502 SBC systems are designed with more or less KIM-1 copied parts of the software and hardware. On this site you can find many examples!

On these pages I will try to explain how all this is working together. It will not be a rewrite of the KIM-1 user manual, read that first, but more a deeper personal dive into the software and hardware of what the makes the KIM-1 tick. It also expects a basic knowledge of the 6502 and digital electronics.

Based upon my experience and study of the KIM-1 since 1979. The first years to learn the 6502 CPU and the 6530 RRIOTs. The next time when I wrote the KIM-1 Simulator (2015 to now). Many notes on paper and files everywhere. Now consolidated in a lot of pages.

Work in Progress July 6-13, 2026