At 11:37 AM -0400 4/9/2009, insightinmind wrote: > >I read in another G3-G5 thread, that really the only time you need >to do "cmd/opt/p/r", is when you change the mobo makeup (excluding >the PCI slots). For example, adding/removing RAM, changing the CPU, >and possibly changing a video AGP card. Is there a possibility that >doing so, could mess up a certain multi-PCI card arrangement, that >was built up, one card at a time, without resetting PRAM each time?
What? sigh. cmd-opt-p-r restores the parameter ram to its default values. Pressing the CUDA button resets (reboots) the Power Management Unit (PMU). IF you remove the Backup Battery (PRAM Battery) while the machine is unplugged, then the parameter ram is reset to its default values AND the PMU is rebooted, when power is restored. IFF the hardware you're fooling with has associated information in the PRAM, then resetting it can help with configuration. Otherwise it's wasted effort. (IFF == IF and ONLY if)! IOW... Most pci card changes can be made without resetting either the PRAM or PMU. It is often recommended that you reset the PMU simply to make it build a new/clean device tree. When changing the rest of the motherboard configuration (cpu etc), always hit the CUDA. Nothing need be reset when adding or removing RAM. Use caution when resetting the PMU. It's twitchy. With the mac plugged in, press the CUDA button ONLY ONCE then wait about 30 seconds before booting the Mac. This gives the PMU time to complete its boot sequence and sniff all the hardware. DO NOT press the CUDA button repeatedly! Interrupting the PMU's boot sequence can result in a mess - the backup battery will then be drained in a matter of days. >My 2 video cards I'm changing back and forth: testing the hardware >setup with the natively supplied GeForce4 MX, and ending up with my >ATI Radeon 9800Pro ME, which, if it doesn't function well in the >GeForce4 MX Hardware tested arena, I need to return to AMD/ATI in a >few weeks for replacement. We often recommend resetting the PRAM when swapping video cards because the default resolution is stored therein. >Let's say I build up my native GeForce4 MX system to include all 3 >PCI cards and it works well. Then, I need to change video cards to >the ATI Radeon 9800Pro ME requiring cmd/opt/p/r. Would it be better >to rebuild the ATI system the same way I built the GeForce system >... adding 1 PCI card at a time, after getting the ATI card to run >alone? It is always better to add things one at a time, just to ensure that each is working. Makes debugging simpler. - Dan. -- - Psychoceramic Emeritus; South Jersey, USA, Earth --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed Low End Mac's G3-5 List, a group for those using G3, G4, and G5 desktop Macs - with a particular focus on Power Macs. The list FAQ is at http://lowendmac.com/lists/g-list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/g3-5-list?hl=en Low End Mac RSS feed at feed://lowendmac.com/feed.xml -~----------~----~----~----~------~----~------~--~---
