Produced corrupt graphics when diagnostic cart was inserted, as shown in the pictures above. Machine was still operating, only the graphics were incorrect. Regular basic boot-up exhibited similar symptoms. The 74LS373 chip (U26) for this machine was received from a faulty supplier, tested with a T48 programmer to be only partially working. It was suspected to be a fake, rebadged chip.
Contributed by Yan Lauzon
Bad U26 (Logic)
