Author Archives: Eric

For the RC2016/10 RetroChallenge, my project is to interface some bubble memory to USB, to act as a very low capacity drive. Bubble memory is the future of non-volatile memory.  Or rather, it was the future of non-volatile memory from … Continue reading →

Due to unforeseen circumstances, I have a shift in focus for the RetroChallenge project. While I may yet do some vector graphics work as previously intended, for the first half of the RetroChallenge I’ve been busy writing VHDL code to … Continue reading →

For RC2016/01, I’m going to hook up an old vector display (the retro part) to a modern microcontroller and either write a new game for it or port an old one. Gee, that sounds kinda familiar. Didn’t someone try to … Continue reading →

I’ve added support for formatting double-sided eight-inch floppy disks to the Quay 900 floppy formatter program I wrote as part of my RetroChallenge 2014/07 project. The source code is still provided under the GPL v3.0 license. I still haven’t worked … Continue reading →

I assembled and debugged one channel of my vector generator, and wrote some of the firmware to drive it. I have unfortunately NOT finished building the second channel, though I got <fingers separation=”10mm”>this</fingers> close. Would you believe <fingers separation=”20mm”>this</fingers> close? I’m going to … Continue reading →

After correcting a few wiring errors, the single-channel vector generator works, though it needs some calibration. I have the vector generator on my test bench with the Silicon Labs EFM32WG starter kit (ARM Cortex-M4F microcontroller) running the firmware, and a … Continue reading →

Bench power supply reports 3.3V@3mA, +12V@18mA, -12V@53mA. Found and fixed a wiring error. With DAC output near 0V, output of first opamp, unipolar to bipolar shifter, is -1.0V, as intended. Next step: hook up SPI to microcontroller. I’ll be using … Continue reading →

I’ve wired one of the vector generator channels on a breadboard, and took two photos. It’s ready for testing, but at the moment I can’t find enough test leads to wire up the breadboard to my three-output bench power supply … Continue reading →

Since my HP 1350A and 1351A vector generators are not working, and I don’t have time to fix them for RetroChallenge, I’m building a simple vector generator from scratch. The design is a slightly updated version of Steve Ciarcia’s design … Continue reading →