Tiny302 is alive!

A project log for Tiny302

A homebrew minimal 68302-based SBC

PlasmodePlasmode 01/09/2018 at 14:340 Comments

The board grew larger.  I've had memory diagnostic errors and I thought it may due to noisy 5V so I added a 5V power plane to beef up the 5V power.  It turned out it was due to a faulty documentation of the 128K static RAM. Two of the pin assignments were incorrect! Once that was corrected, the memory diagnostic passed. I also added a RS232 transceivers to interface with the serial port--the funny looking connector at the right edge of the board mates with pin 2, 3, and 7 of a serial cable.

The software development went well. It currently is running a monitor/debugger of my own design. It does the basic file load, memory read & write, breakpoint and trace functions. It also has a RAM/Flash remap command so Flash is mapped to high memory while RAM mapped to $0. With that I'm able to load a modified Tutor v1.3 and see it running. So I guess I'm done with the board. I'll pour epoxy over the surface mount parts to keep them from shorting.

Below is a screen shot of Tiny302 booting up; a help menu of the monitor/debugger; remap command ('sw') to swap RAM and Flash; load the modified Tutor; and Tutor help output.