[sebhc] H8 memory test in H17 boot ROM

[Jack Rubin]

The infamous memory test presented in the Heath H8 memory board manuals
is incorporated into the H17 ROM. Normal boot entry is at 030 000, but
the memory test is found at 030 003. 

The procedure is outlined on page 4 of the H17 manual - load the jump
address into PC, read the top of memory value from 050 000 and run the
test (key sequence - REG, PC ALTER, 030 000, ALTER, MEM, 050 000,GO,GO
[yes, GO x 2]). 

The data register should start counting up from 000 to 377 and then
repeat until you reset the machine. For most of us, the count will fail
somewhere along the line and then the bad memory location will need to
be decoded from the info in HL as per the memory manuals. Or just swap
boards/chips/addresses until the damn thing boots and worry about the
bad chip(s) later when your programs won't run.

Jack

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