> But, I have some 3.25" drives that use same connectors as "standard" 3.5" > drives, ("4 pin Berg"?) EXCEPT 5V and 12V are swapped in their positions > in the coneectors!
I have an Archive Sidewinder tape drive on one of my PERQs. The power connector is the same as a 5.25" floppy drive power connector but the 2 voltages are +5V and +24V. At least the +5V pin is where you expect it. I am told some Sun workstations (Sun 2's???) had a power harness to feed both 5.25" drives and a Sidewinder. The only dfference between the connectors was the colours of the wires going to them. Of course plugging an RS232 cable (DB25, none of this DE9 nonsense!) into a PC printer port (or a PC printer cable into an RS232 port) is a good way to let magic smoke out of some TTL chips... It didn't let any magic smoke out, but I once had to sort out a 10base2 ethernet system that was behaving very oddly. Putting a 'scope on the cable showed a signal the likes of which I'd never seen on ethernet before. I cranked the timebase down and recognised it. Composite video (RS170-like). Some 'genius' had plugged an unused ethernet T-piece into the BNC connector on the back of a VT220... -tony