Port CP/M-68K to MPU302, part 4

A project log for Reverse Engineering Soneplex SPX-MPU SBC

Reverse engineering logs for salvaged MC68302 based SBC

plasmodePlasmode 12/30/2017 at 16:000 Comments

The compact flash breadboard is turned into a pc board.  I added a 2.5mm power jack for 5V power.  When plugged in, the daughterboard ground one of the discrete inputs on the DIN41612 connector.  During CP/M initialization the BIOS checks the discrete input and automatically adds the CF drives if the daughterboard is detected.  The board also bring out the 2nd serial port to a header as well as the SPI interface of 68302.  This should make experimenting with SPI & serial interface easier.  It is a very simple design and produced by SeeedStudio for 49 cents/pcs (in quantity of 10).  Shipping from China, $20, is by far the most expensive part.

The schematic, Gerber photo plots are uploaded in the Files section.  Below is the picture of CF daughterboard plugged into a MPU302.