Joe wrote: Not sure exactly what the ROM chip does on a mac? David wrote: >The short answer is: it tells your Mac that it's a Mac and allows it to >"be". That fuzzy enough for ya?
The slightly longer answer is that ROM (read only memory) is an IC (integrated circuit aka chip) than has information burned into it that a computer needs to get the startup process going, among other things. When you press the 'on' button, the different components have to recognize each otherand begin to interact, and the ROM provides this service. Apple ROM is typically 4 MB these days, a far cry from the original Mac which had 64 k of ROM. Other functions built into ROM since the introduction of the PPC chips is the emulation code that allows later model Macs to 'emulate' pre PPC Macs and so read and write to Applications that aren't 'native' PPC code. Unfortunately, ROM also contributes to a computers obsolescence, as later software may not be recognized by ROM built into earlier machines. Many early Macs (eg 2Si) have a ROM slot left empty for future ROM upgrades, but the speed of change in computing has meant this feature has never been used. Recently, I was able to get a Mac SE/30 to recognize OS 8.1 by substituting the original SE/30 ROM simm with one from a 2Fx, which was kinda neat. I'd be really surprized if the ROM simm from a Nubus based Mac 7100 would even fit the ROM slot of the PCI based PowerCenterPro. What you might try is the oft mentioned workaround of connecting your PCP Hard drive to the 7100, doing the OS 9 install, then putting it back in the PCP. Only the Power 18 / 100 / 120 's were Nubus based PowerComputing units. They were essentially Mac 8100's without the AV feature. The PowerWave, PCC's flagship unit before the PowerTowerPro, had an optional 'Stargate' card available that allowed Nubus cards to be used in that PCI based computer, an important consideration for folks who had laid out $3000 - $4000 for a high end video card like the Radius 1600 GX. Over to you RHB. You can tell the folk about simmtrees which (theoretically) allowed the 16 mB 30 pins simms from your 2Vx to be used in 72 pin models...=) Cheers...Michael -- Power Computing is sponsored by <http://lowendmac.com/> and... 123Inkjets.com <http://lowendmac.com/ad/123inkjets.html> Support Low End Mac <http://lowendmac.com/lists/support.html> Power Computing list info: <http://lowendmac.com/power/list.html> --> 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]> List archive: <http://www.mail-archive.com/powercomputing%40mail.maclaunch.com/> Using a Mac? Free email & more at Applelinks! http://www.applelinks.com
