PCB in progress

A project log for Merlin

68000 Retro Super Computer

Matthew PearceMatthew Pearce 01/17/2022 at 09:210 Comments

First PCB is in progress. It will all run at 3.3v, breakout the Rosco style 68k bus and also provide an 8 bit RC2014 bus for a Z80 multicomp running at 10mhz which will handle slow retro cards and hardware. It will also move the GD dazzler off the arty to give me access to the chipkit pins as well as the arduino pins - increasing the gpios available, plus breakout the I2C pins from the arty as they have built in Pull-ups on.

I am looking at different level shifting techniques once I get the 3.3v running. This will give me access to 5v TTL and CMOS hardware. 

On the FPGA side - I've added block ram to the map for stack variables to use which should speed up data accesses. I've also started working on code for a l1 cache. The testbench version is working.

On the software side, will now start a text console using the Gameduino and keyboard ps2 integration.