Hi Guys, While we are on this topic, may I know how do I 'switch on' the ATX PS directly and independently ? Ie. the ATX PSU is not connected to the Mobo. Just FYI, my PC died recently and I have switched to Notebook as a desktop replacement. However, storage is a problem (too little on a NB). Hence, I am reusing my 3.5" hard-disk and DVD Writer by placing them into external casing. The problem is, each external casing comes with its own PSU. This mean, I have to remember to switch on each one of them everytime when I want to use them and 'off' when I am not using them. Imagine, what if I have 4 such external devices (2 hard-disks, 1 DVD Rom and 1 DVD Writer). I thought why not make use of a typical ATX PSU which has ample number of PS cable that is used by Hard-disk and CDRom drives anyway. If I can 'feed' each external device with a PS cable from the ATX PSU, I just have to switch just the ATX PSU on/ off only !! Thanks in advance for the help. cheers, Davis Peter van Hoof wrote: Hi Marc, Go to: atx12v power supply guide http://formfactors.org/developer/specs/ATX12V%20PSDG2.01.pdf section 3.3.2 and see the specs. I'm not sure if this is the way to go because you will have to maintain low level to keep the supply turned on i am not sure if after an initial low the motherboard will take over. It would be annoying if the motherboard cannot switch the supply off. A better solution is probably interfacing the case switch side of the motherboard Peter van Hoof ----- Original Message ----- From: "Marc" To: Sent: Wednesday, July 14, 2004 6:15 PM Subject: [EE]: ATX power on? > Hi all... > > Best I can make out, to trigger power-on on an ATX motherboard, you need > to pull to TTL low momentarily? Anyone vouch for this? > > Is decoupling or anything else required on this signal path? My goal is > to control on/off of an ATX PC (and power supply) via a PIC and IR. > > TIA, > > -marc > > -- > http://www.piclist.com hint: To leave the PICList > mailto:piclist-unsubscribe-request@mitvma.mit.edu > -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu --------------------------------- Do you Yahoo!? Yahoo! Mail - 50x more storage than other providers! -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu