From: [EMAIL PROTECTED] Message-ID: <[EMAIL PROTECTED]> Date: Thu, 11 Sep 2003 12:11:19 EDT Subject: Re: 8500 ROM
Also, I think it is speculation (unproved ?) that a "Tsunami" ROM SIMM, which will physically fit in an Apple Network Server mobo ("Shiner"), will convert that machine into a Mac.
It will not, as the "Shiner" has a PC-type onboard video.
The problem is that the PCI interrupts are wired differently on the ANS/Shiner than they are on the PM9500. Otherwise the system architecture is the same with only minor variations. Since the interrupt arrangement is hardcoded into the firmware (ROM) of these machine rather than determined dynamically, as on later machines, this is a fatal problem.
The on-board video isn't really an issue because it just looks like another PCI card. It does have the problem that the firmware for the onboard video is in the ANS ROM and, naturally the 9500 ROM lacks that firmware, so the onboard video can't function with a 9500 ROM.
The two Fast & Wide SCSI controllers on the ANS have the same issue with the additional issue that they are using a couple of interrupt wires. The 9500 expects those interrupts to be connected to the Bandit chips, so probably when the ANS generates a perfectly normal interrupt from the SCSI chips, the 9500 ROM tells the machine that there's a major problem and the machine hangs. Of course, the 9500 ROM also lacks the firmware driver for the SCSI chips.
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
