Off-Market MEGA65 Devkit

The MEGA65 booted
Booting the latest MEGA65 bitstream on the Nexys A7100T FPGA development board.

Recently the MEGA65 project began selling their first batch of official development kits. Naturally, they sold out before I could get my hands on one; luckily for me (and many others), the latest bitstreams are still being built for the off-the-shelf Nexys A7100T/Nexys 4-DDR FPGA development boards!

The FPGA development board itself
The Nexys A7100T development board that I’m using for the core of my MEGA65.

Now, by using an off-the-shelf FPGA development board in place of one of the custom designed MEGA65 r3 devkits, you’re obviously going to be missing a lot of the peripheral features right out of the gate (such as the injection molded keyboard + housing, expansion port, joyports, IEC, second SDcard, etc). However, with a little bit of luck and a lot of fudging, you can find substitute parts for all of these to wire into the IO expansion headers on the Nexys A7:

I’ve already decided on parts for the chassis and keyboard (pictured in the gallery above). I knew I was going to end up using one of my spare Commodore 64C shells for this, and since the MEGA65/C65 uses an extended keyboard layout similar to the PC/AT, i couldn’t just use a standard C64 keyboard assembly. I thought finding a fitting keyboard was going to be tough, but pretty quickly i managed to find a donor Thinkpad matrix that covers the c64c faceplate perfectly!

There’s still a lot that seperates this from a ‘complete’ devkit, but what I have working now is all I really need for a bare-minimum development platform!