Author Archives: Eric

As seems to be usual, my stated plans for Retrochallenge didn’t come to fruition.  Several times I’ve planned to do vector graphics stuff, and not done it, so this time I planned to do something else, USB bubble memory. Of … Continue reading →

Some years ago I obtained a few Data Check 5045 digital vector displays from HSC Electronic Supply. Data Check bought the product line from HP, where this model had been the HP 1345A. HP used these in some of their … Continue reading →

Some years ago I obtained a few Data Check 5045 digital vector displays from HSC Electronic Supply. Data Check bought the product line from HP, where it had been the 1345A. HP used these in some of their own test … Continue reading →

I’ve made a small amount of progress on the code, but nothing particularly noteworthy. I’ve given some thought to the design of a 3D-printable enclosure. I’m not sure whether I’ll end up needing a fan. I’ll put ventilation holes in … Continue reading →

My GPIO fix for pin numbers vs. masks needed to be made in a few more places, so I’ve done that now. The Intel D7220-1, like many peripheral chips, uses a chip select input (CS) for programmed I/O, but a … Continue reading →

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 →