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A project log for WICE-4M

Leap Electronics WICE-4M EPROM Emulator Reverse Engineered

forthnutterforthnutter 09/27/2019 at 22:561 Comment

I did not do much research on the TXB0108 series of level shifters, the output pins do not have enough drive to switch a Parallel port with pull up resistors with 1K on the WICE, My bad, a redesign is on the way.


Dave's Dev Lab wrote 09/27/2019 at 23:16 point

yes the entire TXA, TXB and TXS series were specifically designed for low power embedded devices such as terminals and cell phones. good ol' 7400 is the best choice... one thing you could considering is using an ISA 8-bit parallel power card or at least duplicating the schematic/design. the full schematic of the parallel printer adapter card is available in the IBM 5150/5150 technical manual, and you can pick one of the cards up on ebay...

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