Oh, good grief! Did I say -12V!?! I MEANT -5V! They all have a -12V connector, but only the SE has a -5V connector. Sorry.
Either way, the -5V serial power is converted on the 128k-Plus logic board from the -12V supplied by the analogue board. This must also be the case on the Classic series as well (if at all). On the SE, the -5V for the serial bus might be supplied directly by the analogue board. But I have a different theory after looking at the SE's pin-outs. It would seem that the SE PDS slot, which is the only B&W compact to have a PDS device expansion slot, has a -5V pinout as well as offering the other voltages. Rather than re-design the serial interface for the SE only since no other of the Mac II family has a -5V power connector, my guess is the -5V is specifically intended to supply the SE PDS connectors only. The -12V to -5V serial power conversion, if any, still occurs on the logic board just as it did for the 128k-Plus. So the only thing that can't be used with the SE series logic boards when used in another Mac is the PDS slot (at least for any cards that use the -5V pin). Then again, you'd have to modify the rear case of any foreign Mac you move the logic board to permanently. And if you're doing that, I guess you could rig a -5V output too. But that's not really the point (lest we make a nifty wind chime out of Grandpa's bones). Thoughts? > From: Doug McNutt <[EMAIL PROTECTED]> > > At 10:34 -0700 6/20/05, <[EMAIL PROTECTED]> wrote: >> The SE series is the only one that has a -12V connector. What if anything >> can expect to happen if I do not connect this to a 128k-Plus or Classic, or >> supply it to the SE, logic board? > > The negative power supply is most importantly used to support RS 232 > compatibility in the serial ports. It may have no other function and it may be > -5 volts rather than -12 volts on some Macs. > -- Compact Macs is sponsored by <http://lowendmac.com/>. Support Low End Mac <http://lowendmac.com/lists/support.html> Compact Macs list info: <http://lowendmac.com/lists/compact.shtml> --> AOL users, remove "mailto:"; Send list messages to: <mailto:[email protected]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive:<http://www.mail-archive.com/compact.macs%40mail.maclaunch.com/> --------------------------------------------------------------- iPod Accessories for Less at 1-800-iPOD.COM Fast Delivery, Low Price, Good Deal www.1800ipod.com ---------------------------------------------------------------
