A very simple 68008 system

I bought a couple of 68008 CPU’s years ago always meaning to make something, as the 68000 series has a great instruction set and is fun to code on! First job was just to verify that I hadn’t been sent a counterfeit or DOA part… sadly something that is always a possibility theses days. As…

Reference counting with C

For the purposes of this post, a very simple scenario is going to be considered. Given a Model structure that holds a pointer to a Mesh structure, the issue to be addressed is to whether or not there are references to a particular Mesh. Once all Models that reference a Mesh have been freed we…

ULX3S – Z80 redux!

While originally waiting for my board to arrive I found and got a Z80 soft core working (in simulation) I was a little disappointed that tri-state logic seems to cause issues with yosys (I think that might be what was causing the logic “loops” later down the toolchain anyhow). Having recently gotten around to soldering…

ULX3S (ECP5 FPGA) first look.

I’ve been wanting to try project Trellis out for a little while now, I was impressed with the open source toolchain for the ICE40, however the ECP5 has everyones favourite feature (MOAR!) it’s basically bigger and faster – what’s not too love. There is a slight issue with the current state of the toolchain, but…