Got a digital talkpath (the blue box) with no power supply. What are its power specs (side of the unit says 18 volts, but makes no mention of amperege). Trying to find a suitable replacement.

It depends upon the processor. There was one power supply for the 386/486 units and another for the 586 units. You'll need to find out which one you have. I do know that Novus (866-331-1112) stocks them for a reasonable price.

The 18 volt unit is 2.0 amps output AC. Since it is AC, the plug isn't polarity-sensitive.

Any way of figuring out which processor I have without booting up?

The 386 and 486 units have a label on the motherboard. I've never opened up a 586 unit.

The model number for the 386 is 303-0X (X=number of ports. The 304-0X is a 486 and so on.