Category Archives: RetroChallenge

In a GPIO initialization function I’d written, I was passing a pin number as an argument to a vendor function that expected a mask. Changed it to 1 << pin, fixing both the LED and USB problems. Windows 10 isn’t … Continue reading →

I’ve continued working on the firmware, and have run into two problems: I can only turn on one of the four LEDs on the Tiva board. The other three obstinately remain off. I don’t really need any LEDs, but this … Continue reading →

I’ve started writing the firmware for my Retrochallenge project. For the USB to bubble memory interface, I’m using a Texas Instruments EK-TM4C1294XL “Tiva™ C Series TM4C1294 Connected LaunchPad Evaluation Kit”, which is based on the Tiva TM4C1294NCPDT microcontroller. This has a … Continue reading →

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 →