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Close but no cigar

June 4, 2014

I’m using the original olduino board to exercise the cpu card so I can see what it reads and writes.  I have a little routine loaded in the avr that resets the 1802, switches to load, puts 0x55 on the bus, and loops pressing ‘IN’. Before I fixed this last issue I was consistently reading FFs.  Now I get a hodgepodge of values probably indicating that my writes to memory aren’t working so i’m reading back whatever was there before.  Still, mustn’t grumble.

ok, ok, wait. I hadn’t clipped the trace from pin 9 of the 4093 to pin 5 of the 4013. I bet *that’s* it!

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