Q: PowerMac 7500/100 Boot Errors
| I have a PowerMac 7500/100 that I am trying to boot with Mac OS 8.0 to recover files. The system folder on the internal SCSI hard drive is corrupted due to partial drive failure, but most of the files are accessible. I have an ATA hard drive connected through a PCI ATA controller that I am trying to copy files to. I do not have a recovery CD, but I have a recovery ZIP disk. I had been able to boot from the ZIP disk, but recently there have been problems and I no longer can boot from it. |
There are two problem scenarios. These happen when I try to boot from the recovery ZIP disk. The most common is that it will boot completely, but as Finder is loading a dialog will appear saying "System Error 41 has occurred. Please try restarting with extensions disabled." System Error 41 seems to be a memory full error, but I am unclear as to whether it is referring to drive space or to RAM. I tried restarting with extensions disabled, but the same error appeared. I also tried installing a 64MB stick of RAM in an empty slot to see if there was too little RAM, but it had no effect. The second scenario is that it will boot until about half of the extensions have loaded, and then a dialog will appear saying "System Error 10 has occurred. Please restart." This error occurs less often than the first.
If I try to boot from either hard drive, I get an error dialog that says that System 7.1 is not compatible with my computer. I do not have System 7.1 on the computer, I have OS 8.0 with a corrupted system folder.
I tried reseting PRAM and NVRAM, but there was no effect. I tried to rebuild the desktop, just to see if it had any effect, but it showed the same system error 41 before anything happened. I tried booting with an OS 9.2 recovery CD, but it was not compatible with the hardware. I have an ATA to USB adapter that I tried to connect the ATA hard drive to another computer running Windows 8.1, but the filesystem was not compatible, and I could not read disk. I do not have any adapter for the SCSI disk, and the ones I have found online are too expensive. The SCSI disk is the one that I am trying to recover files from. The hard drives do not make any noises that would indicate serious failure (ie. click of death). I have a firewire PCI card that I have considered installing to see if I can get it to boot over firewire, but the only other macs I have that have firewire are an iMac G3 and a mid 2010 Mac Mini, so I do not expect that that could work.
The problem started while I was copying files between the hard drives. Finder crashed when a disk error occurred in the copy process, so I restarted the computer and the errors began and have been happening since.
I have tried everything I can think of and Google returns nothing helpful. Hopefully my description of the situation is not to confusing. Any advice would be appreciated. Thank you!
PowerMac 7500/100, Mac OS 8.6 or Earlier
Posted on Jan 20, 2016 6:19 PM
Keep in mind that it's possible for electronic component failure to occur on the hard drive's logic board, that would have no effect on the motor spinning the platter normally and producing no abnormal sounds. If the onboard SCSI CD-ROM drive is functional, why don't you check ebay for a compatible Mac OS retail version (universal) installer disk of Mac 8.0, 8.1, 8.5, 8.5.1, 8.6, 9.0, or 9.1, to boot the computer? If successful, you could transfer the files to the SCSI Zip drive. What brand of ATA controller card were you using - Sonnet, Acard, or SIIG? A compatible ATA PCI controller card (in Macs that support it) must have Mac firmware in order to boot the computer. A bootable controller card cannot be driver-based — it must be firmware-based. An ATA controller card designed for use in PCs will not function correctly in your 7500, and leaving it installed in the PCI slot may cause problems booting it. The same problem applies to booting from a FireWire PCI card. Because the 7500 doesn't have onboard FireWire, its programmed ROM code doesn't include support for FireWire booting. Support for using (but not booting from) a device connected to a FireWire PCI card would be driver-based, with the extensions installed on the boot drive. How full is the Zip disk from which you're trying to boot? If there are any thrift stores or computer resellers/recyclers in your area that sell older computers and related peripherals, your other option would be to look for an inexpensive, working Power Mac that has onboard SCSI, even something as new as a beige G3 desktop/mini-tower. You could transfer the 7500's SCSI drive and ribbon cable to the onboard SCSI bus on the G3's motherboard and transfer the files to the G3's boot drive or another IDE drive connected to the second ATA bus. Other good models would be a Power Mac 7300, 7600, 8500, 8600, or 9600, as each has (2) onboard SCSI buses. Obviously, you'd be spending money to buy ad hoc hardware, that will be useless to you after accomplishing your file transfers. I'd recommend finding a compatible Mac OS installer disk.
Posted on Jan 21, 2016 9:10 AM