PowerMac 7600 and SCSI2SD issues

[nymunariya]

I've had a 7600 for a little over a year now. It was a steal at 36€ and in great condition, only downside is it had very little ram, only standard vram the 604 processor, and a 300MB harddrive that was repartitioned to around 150MB (other partitions are MIA at the moment).

I've already spent more money upgrading the darn thing (NewTec G3, SCSI2SD v6, ram). I don't know if it's related, but I found out one of the ram slots don't work. I've moved the ram to another slot, and it's recognised.  I haven't done any ram tests (is there even a mac equivelant to memtest?)

Anyway, I got a SCSI2SD. Typically I've been using two paritions (or two "separate" drives), one with 7.6(.1?) and one with 8.6.  (I grew up with System 7, that's a classic look) But somehowever, the 7600 is never really happy with the SCSI2SD.  There are two problems that keep happening:

1. While I'm booted into 7.6 (SCSI2SD or internal HD) every now and then something on the 8.6 partition gets corrupted, preventing me from booting into it anymore. Over the weekend I got the error that the 8.6 system was not compatible with my system. Since I can't troubleshoot the HFS+ drive from 7, I have to plug the SCSI2SD into my Pismo, format the drive, and copy over everything again.  One time, despite the drive being formatted as HFS+, all the files became visible on 7 as it somehow *lost* the HFS+ formatting. (it was amazing.  If only I get 7 to read HFS+ more)
   
2. When copying files to or from the internal HD to a SCSI2SD partition, the files get corrupted. Doesn't matter if I'm copying HFS to HFS or HFS to HFS+, programmes refuse to start, documents won't open.
   

Does that sound like a SCSI2SD configuration error? Or could I have bad ram?

I don't have a second SCSI HD or SCSI2SD to test.  I have tested various SD cards from 4GB in size to 32GB, with partitions from 2GB (for HFS) up to 32GB (for HFS+). While the 7600 has a second SCSI bus (I believe) I could try, I do not have a second SCSI cable lying around.

I don't know if it's relevant, but as far as SCSI2SD formatting goes, while I can initialise in 7.6 (with patched drive setup) I cannot format them in 7 (at least not from internal SCSI HD).

I have also never been able to install 7 (or 8 ) to the SCSI2SD.  7 times out--even when booting from a 7.5.3 install cd.  And I can't get a burned install cd of 8.5 to boot.  So far my only success was copying over systems I prepared on Sheepshaver with 7.6 and 8.6.  And as I discovered this weekend, my 8.6 install doesn't appear to have any AppleShare installed, so I can't connect to any other computers over the network.  And trying a fresh install is currently a nightmare--but I might be able to make a fake CD install partition on the SCSI2SD.

Here's what I posted on reddit in January while I was having SCSI2SD setup woes.

Any thoughts or recommendations?

 

[nymunariya]

it was blind writes. 

The 6.2.3 version notes of the SCSI2SD util says:

• Add new config option to enable blind writes to improve SD card write performance. This was option was previously enabled default but causes problems with some SCSI hosts. This option must be disabled on 68K Macs if there are errors when writing data.
  

And yup, that was it.  I mean, I also updated the firmware and disabled the blind writes and it's like I have new computer.  Finder doesn't complain about the drive. 8.5 was able to install correctly (which was super stressfull), but everything else seems to run perfectly.  Copying is painless.  No corruptions.  Just Adobe Reader 3 didn't spazzed out and wouldn't install.

 

[LaPorta]

Thank you for this. I had the exact same corruption issue with a v6, and gave up. Now maybe I can install it back into something else.