Software

The board requires 2 firmwares : one for the PIC, and one for the 68008.

The PIC will be described in another section.

The 68008 monitor code is a modified version of the TUTOR code, made by Motorola in the eighties. I found this page, which shows a picture of the original evaluation board from Motorola (MEX68KECB). The code is pretty well written, and also easy to adapt to any 68k based board. In my case, I had to adapt the input/output routines to talk to the PIC instead of the DUART, and rip the tape load/save commands.

The monitor provides an extensive set of commands, which makes it ideal to learn assembler. The only thing that I found missing was an way to upload binary files to the board, and therefore I added a ZMODEM receive command. I also added 2 commands to work with the FLASH (‘FE’ for Flash Erase, and ‘FC’ for Flash Copy), as well as 2 commands to get/set date and time (‘DA’ and ‘TI’ respectively). The new monitor code source can be found in the download section. Note that I am still actively enhancing this code, so things may change. The zip file contains the original TUTOR code. The Makefile requires ‘unix68k’, the unix version of Professor Chuck Kelly’s easy68k assembler, and srec_cat, a utility to manipulate S-records. The later is part of SRecord-1.4, that can be downloaded at SourceForge.