>From: [EMAIL PROTECTED] >Date: Sat, 5 Oct 2002 19:34:20 EDT
>Therefore, one can power an early Mac PCI mobo (an 8500, e.g.) from an ATX >power supply, in an 8600/9600 case, provided: > >1) an adapter plate is made for the ATX power supply, > >2) the 20-pin ATX power supply cable is ... somehow ... adapted to the 22-pin >and 10-pin power supply cables required by the 8500/7500/7600/7200 mobo >powering system. > >It's an interesting project, and not an impossible one, although I would >classify it as being "very difficult". Hmmm. I may disagree with this assessment, but I guess it depends on who the audience is. I think I could whip one of these up in about two hours with parts on hand. Probably three hours total as I'd need 1/2 hour to make sure I have the pinout listings or get them from XLR8yourmac.com articles. And the soldering pencils take about 30 minutes to warm up satisfactorily. The necessary parts are available from DigiKey. The plastic housings are Molex Mini-Fit Jr. connectors. The Receptacle Housing (which is the part that plugs into the motherboard) is WM3704-ND for the 10 pin, WM3710-ND for the 22 pin and WM3711-ND for the 24 pin. Costs are $.68, $1.87 and $1.24 respectively. The 20 pin Plug Housing to which one connects the ATX supply is more difficult. Digi-Key does not stock it in acceptably small quantities (minimum 100 or 1000 last time I checked.) However, the Mini-Fit BMI mates with the Mini-Fit Jr. and the 20 pin BMI Plug Housing was available the last time I checked as part number WM3616-ND for $2.10. Another possibility is to get an ATX PS extender cable. It will have the 20 pin plug housing at one end, with conveniently attached wires. Just clip off the wires at the motherboard end of the extender and much of the work of building the adapter is done. The pins that go in the Receptacle housings are WM2501-ND and the pins for the Plug Housings are WM2500-ND. There are ridiculously expensive crimping tools, but you can do it with a pliers. That's why it takes a couple of hours. Otherwise it would go much faster. Anyway, the only other trick is that one must run the Power-On wire through an inverter (methods described in articles on XLR8yourmac.com about ATX to 8500 and 9600 PS conversions) so that the soft power on will work. Don't worry about running one ground, 5V or 3.3V line from the ATX supply connector to two pins on the motherboard end, if you run short of the needed connections. All the 5V connect to each other on the MB. Similarly for GND and 3.3V. Obviously, some connections must double up if you're going from 20 wires to 32 or 34 wires. Here's an article on doing a similar conversion for the Umax S900/J700. It's at http://www.io.com/~trag and then look for a file called something like Umax_ATX_PS.sea or some such. Once you get it expanded it's SimpleText. Jeff Walther -- PCI-PowerMacs is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Refurbished Drives | -- Sonnet & PowerLogix Upgrades - start at $169 | & CDRWs on Sale! | Support Low End Mac <http://lowendmac.com/lists/support.html> PCI-PowerMacs list info: <http://lowendmac.com/lists/pci-powermacs.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/pci-powermacs%40mail.maclaunch.com/> Using a Mac? Free email & more at Applelinks! http://www.applelinks.com
