The Apple 1 monitor (Wozmon) to be included in the empty space in the KIM-1 tape ROM
The Apple 1 and the KIM-1 are some of the earliest 6502 systems made.
Both are desirable, Apple 1’s sell for lots of $$$ and KIM-1s are getting more expensive.
Luckily we can build a KIM-1 clone that is either cheap and compatible, like the PAL-1, or a bit more authentic as the various KIM-1 boards.
Anyway, a clone has the KIM ROMs, in an E(E)PROM, to make it a KIM-1 clone. Altering is not done, you loose that unique spartan user interface!
The Apple 1 has also a monitor program, often called Wozmon to honor the genius of Steve Wozniak.
And you can combine both user interfaces on a not expanded KIM-1 clone!
Ronny Ribeiro, a user of a PAL-1, saw that the KIM tape ROM has quite some unused space. In a real KIM-1 that is wasted, you cannot program the ROM.
In a clone you can. He saw that that free space is large enough to hold the Wozmon, adapted a bit for the KIM-1 TTY I/O.
He offers a ROM image for a clone, with the Wozmon built in at 1AA0. And added a command to go back to the KIM-1 monitor.
He also replaced the ‘KIM’ prompt in hi system with ‘PAL.
Two versions here, original KIM ROMs in 2K image (00 filler bytes!) with Wozmon in tape ROM empty space (and no change to text in the KIM ROMs)
– wozmon kim rom zp24.bin with zeropage used from $24 as original Wozmon
– wozmon kim rom zpe5.bin with zeropage used from $E5 just below start of KIM-1 monitor zeropage
Start Wozmom at $1AA0, used buffer at $0300
Based upon the ideas and work of Ronny Ribeiro.
Source included. Standard 6502 assembler, I used TASM32
The KIM-1 Simulator is used to test this. And this Wozmon is now available in Settings!
Here I offer you that ROM. I reconstructed the source and added the result to the KIM-1 ROM image. WIthout the KIM prompt change!
In the archive you find source etc of the Wozmon for KIM, the binary ROM image to load in the KIM clone rom, the original Wozmon source and a small userguide by San Bergmans.