GC-1000 Clock uPs

[Terry Perdue]

I have about a dozen microprocessors for the GC-1000 available. These are
not the masked parts used in production, but prototyping chips with a socket
on the top for an eprom. The 444-200 p/n contains code for the serial
interface option as well as the clock; the uP can be used either place.
There are two things to be aware of when using this chip: (1) I believe that
the 444-200 code was revised at some point for some reason (anyone know for
sure?), although there are countless clocks still running fine on this code
and, (2) you may need to add 10K pullup resistors from pins 38 (external
interrupt) and 39 (reset) to pin 40 (+5V), as these were provided internally
in the production part. (If you check your schematic, you may find they're
already on the board.)

I'm asking $50 each for the uP plus eprom, programmed for 444-200, postaid.
I don't have a GC-1000 to test them in, so I'll offer a refund for any that
is found defective and returned within one month. Anyone interested?

Terry Perdue K8TP

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