I’ve slowly been working on writing an extended KIM-1 monitor program and getting the SD card interface running on it. Here is the latest version showing the KIM prompt right after a reset, followed by a call to my new monitor at address E000:
All of the commands listed are working. The L command is handy because a standard Intel HEX format file can be downloaded from the terminal emulator. The SD Card interface is also working, using the two unused I/O ports on the KIM. The other end is our standard Arduino based SD card system, exactly the same one used for the 6800 and 6809 versions of FLEX. No changes are needed to work on the KIM.
This is the adapter for connecting the standard SD Card System to the KIM’s parallel ports using our I/O Card:
This is the collection of boards. Upper left is the SD card system, next to it is the RAM/ROM board, below that is the I/O card and the parallel adapter is facing straight up, making it hard to see:
There was no standard DOS for the KIM, so in the mean time I’m just adding a few commands to do disk directories (example above, being the program Farmer Brown from The First Book of KIM). Next step is to allow the L command to load from a file on the SD.
The extended monitor is on an EPROM on the new RAM/ROM board and currently consumes a tad over 1.5K of the 8K EPROM, which includes the command interpreter, help, and the SD functions. Someone could easily put a Tiny BASIC into the EPROM.