Thursday, 4 February 2016
VIC20 IEEE-488 Cartridge
I have been working on various VIC20 cartridges recently. One that I was interested in building was an IEEE-488 cartridge. I had previously tried out the PET microSD with a VIC20 IEEE-488 cartridge, and found it worked well.
IEEE-488 diagnostics board confirmed the problem, comparing the outputs on the LEDs when sending the same commands to the 6522 on the Stack and my new board showed the outputs were inverted. Sending 00 turned all the LEDs on the databus off on the my board. Sending FF turned them all on.