Apple was not the only company. Iomega used it on the SCSI ZIP drives, and there were quite a few other peripheral makers that used it.
I think I even had a Compaq with one back in the late '80s or early '90s; but I may be remembering wrong.
To be accurate, GAP should have phrased it as "DB-25 port", yes. (P.S. I don't see you correcting people who improperly use "DB-xx" to refer to ports other than the width of the DB-25 port.
-- For those who don't know, only the DB-25-width port is properly "DB". The port width that is used for older 9-pin serial, or 15-pin VGA, usually called "DB-9" or "DB-15" is actually "DE-9", or "DE-15", (ports with two rows of pins are 'normal', ports with three rows are sometimes appended "HD", so VGA may be called "DE-15HD"; except the "DD" size, for which three rows are normal, and four are "HD",) and the port that is used for Apple's older 15-pin Apple video plug, doing double duty as the PC "joystick" port, is properly "DA-15". The second letter refers to the width of the plug, where certain letters are defined for certain widths. See http://en.wikipedia.org/wiki/D-subminiature.)So, back to the question at hand.
The original poster is looking for the pinout of the DB-25 port that does duty as both SCSI passthrough and power. And, yes, he is saying that he has the PowerCD unit, plus a DB-25 cable (or at least an end) to sacrifice to turn into a power connector. He just needs to know the pinout to make his custom power cable.
I offered to help him over at The Vintage Computer Forums, but my PowerCD and base appear to be firmly in storage, out of easy reach; so I referred him here.