Got it cleaned up, plugged in, powered on fine.
Run a DB25M-Db25F cable, then a DB25-DB9f adapter to the PC.
Nada.
Zip.
Zilch.
"Error communicating with programmer - waiting for response"
Fought with cables for about 2 hours.
Went looking in the garage for another db9-dv25 adapter, and I actually found my RS232 breakout box!
Hook that puppy up, and low and behold, looks like the EPROM programmer wants a null-modem cable!
Flip the 2 switches on the breakout box which swap 2<->3 and 3<->2, and
BOOM! Software finds the programmer!
Man - what an exercise in wasted time.
There REALLY is NOTHING like having the right tools sometimes...
Reminds me of Tuesday - went to get front brakes changed on my '05 Tundra, fraking Midas wants *$250* to change *ONLY* the front brakes!
$135 labor, $60 to turn rotors, $50 for the pads!
Bought the pads at AUtoZone on the way home for $20, busted out the impact wrench and sockets, and did 'em in about 90 minutes.
As I said - nothing like having the right tools for the job - whether iit's an air compressor and impact wrench to change brakes, or a digital voltmeter and breakout box to troubleshoot serial comms.
I do NOT have, at least within seeing range, a null-modem adapter. I *DID* locate a LapLink-style null-modem cable, but I need male on one end which it didn;t have, and I didn't have a M-M adapter.
Who knows how much longer I woulda' been playing cable-shuffle without the breakout box!
Tony