Hardware
This is a gang programmer which uses a 8039 microcontroller with 2 P8243 “PIO” chips for I/O. It has two HPDL 1414 displays.
Software
I wanted to create software for this programmer so that it could again be used from a PC.
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This worked. It called serial_read_hex_byte, and then called it again to read the high address, the low address, and the record type byte at 0x3197. After its return however it moved to 319b- which means it saw the record type as something else than zero. That is a good reason for a problem 8-(
So, let’s start sending a record with all zeroes:
| Code Block |
|---|
:000000000000000000000000 |
No effect whatsoever. Whatever I do it always does this sadly enough:
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Next try is to ensure that the data on the 8243 port 7 is correct (probe on the 8243 P7 bit 0):
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That really is what I’m sending right now; zero after zero, and still the bloody thing does not see them 8-(
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