George,
I fully agree. To date, with some probing, it looks like the RSRS board may be at fault, but I don't have a board pinout to be sure. I can see some 232 activity on a resistor on the board, but not much more after that. If I knew the I/O connector pinouts, I could scope it out and be sure. I was able to find info on the 286 WD motherboard (WD286-WDM20) but no pinout info on the serial ports J19 and J20. Are they doing a loop using both serial ports? Anybody know why they are using both serial ports? Is one for the external loop on the outside box? I can try to get a pinout on the IC, but a board level schematic would certainally more useful. I would hate to create more problems from shorting adjacent pins during probing. 1 step forward with 3 backwards is not a good way to go.
Anybody got any info on the RSRS board?
Thanks to anyone who can help!
bryan |