I was just looking at the schematics for the
display/control
board
for the Altair 8800 and saw that there is a 1702 EPROM
on the board.
The
lowest 4-bits of the EPROM's address bus are
connected to a 7493
binary
counter and the highest 4-bits are connected directly
to the address
bus.
What's the purpose of the EPROM? Did the front panel have some
intelligence?
I'm pretty sure that you're looking at an Altair 8800B front panel
schematic. I believe those were software controlled front panels. The
8800 and 8800a had no EPROMs on the front panel - just TTL and the
switches, LEDs, etc.
Erik Klein
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