For debugging power supplies, a 'load module' (a card with only a bunch of resistors on it) is invaluable. No trying to figure out where/how to connect a large load resistor - just plug the board in. DEC made several: M7556 dual - +5V 1A -15V 375mA M9049 M9060-YA quad - +5V 5A M9713-AA dual - +5V 2.75A -15V .75A The M7556 (at least) can be used on both QBUS and UNIBUS backplanes (since they share the same pins for +5 and -12V (QBUS) and -15V (UNIBUS). Probably all the others can be used on both buses, too, but check the pins they draw The M7556 can be easily modified (with a few etch cuts) into a +5/+12V load module, but the resultant board can _only_be used in a QBUS. If you can't find any of these (there are none left on eBay, but other suppliers still seem to have them), another alternative is to get a blank prototyping board from Douglas Electronics (http://www.douglas.com/), and add your own resistors. Noel