Michael WesselI fixed a slight firmware stability problem with the Microprofessor. The `CLOCK.RAM` program is a good stability test. It runs for hours now without any glitch / crash, so I am assuming that this problem has been fixed. At first I though it was due to noise or requiring 74F373 instead of the 74LS373, but these were red herrings. In the end, the GPIO slew rate and drive strength, as well as the hysteresis config were causing the problem. Fixed in Version 1.1 of the firmware now. And here is video showing all the machines with the new firmware:
Firmware Update and PicoRAM Ultimate Galore!
A project log for PicoRAM Ultimate Rev. 2
SRAM Emulator and SD Card Interface for Vintage Single Board Computers (such as the Heathkit ET-3400, Lab-Volt 6502, and Microprofessor)
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