Close

AN1015 lives again after 30 years

A project log for Tiny020

A home-brew minimal 68020-based SBC

PlasmodePlasmode 01/14/2018 at 21:250 Comments

Hand wired the schematic into a prototype board and this is what it looks like.
I'm confident about the 68020 and RAM chips since they are new from proven stock so they are soldered directly to the board. I'm not quite sure about the 68681, it was a pulled part from unknown board and the legs were all bent, so I socketed it. I'm also worried about 74LS138 not being fast enough to decode addresses for zero-wait state access, so they are socketed to be replaced with 74FCT138, if necessary. The flash is in a ZIF socket for ease of reprogramming.

Since I've already developed a monitor/debugger for the Tiny302, the 68020 should be able to execute them with a minimal modification, I programmed that into flash and power up. That works, I have a working monitor/debugger to work with. The design works, and I have a whole list of to-do's for the Tiny020. The top of list is a visual indicator to help me with debugging and code development.

Discussions