Retro Ramblings

This week I was asked to help prepare artwork for a commercial print job.

Some months ago I had the idea of improving the prefetch on the TG68K soft CPU in order to reduce the amount of time it spent waiting for the cache / SDRAM.

Those of us still developing cores for devices containing Cyclone III chips are stuck with an ancient version of Quartus II, namely version 13.1.

I recently bought a Tang Nano 20K FPGA board, due to my interest being piqued by the Nanomig project.

This is my first blog post in more than eighteen months, and while I’ve not been nearly as active tech-wise as previously, I am still porting cores to the Turbo Chameleon 64 (see https://www.patreon.com/coresforchameleon), and more recently I was kindly ……

I recently came across some very interesting one-line programs, which generate some primitive music from simple logic expressions – a genre which has come to be known as “bytebeat”.

I’ve been exploring Yosys / NextPnR / Project Trellis on some Lattice ECP5-based boards recently, and I’ve been very impressed and enthused by what I’ve seen.

2022-05-14 Continuing my experiments with the IceSugar-Pro board, building cores using Yosys and friends, I now have EightThirtyTwoDemos running, using PMODs to provide VGA out, I2S audio out, PS/2 keyboard and mouse, and SD card.

Coping without SignalTap – Part 3 – 2022-04-28 I’ve found the bug which was preventing interrupts from working with the EightThirtyTwo CPU, at least in the EightThirtyTwoDemos projects… … and of course, it was something simple and blindingly obvious.

Coping without Signaltap – Part 2 – 2022-04-26 By the end of part 1 I was able to communicate over JTAG with a design running on the IceSugarPro, remotely control the LEDs on the board and read the contents of … Continue reading →