Cuda

[Mr Magoo]

In an attempt to revive my Power Mac I've been advised to reset the CUDA switch in my PowerMac 8500 with a Sonnet G4 card installed several years ago..

What's CUDA?

How do I reset this switch. Is it like a light switch i flip up to turn on or flip down to switch off ?

Any special or extra advice about resetting and the after affects of such action.


OK guys please stop laughing MR MAGOO is very new to try this DIY computer repairs.

[rwm]

The CUDA will be a small button that you press - it will be on the motherboard. It's been so long since I've seen the inside I'm not sure an an 8500.

Here is an Apple Document it talks about CUDA reset.

Also right here is a discussion of how to get to it. It's tough I think on these.

There should be some good info buried on the MacGuru's forums in the Vintage area. I'll search it some and post any relevant information.

All of the Threads here will have talk of the CUDA look for an 8500. Right here might have an 8500.

Here is a Google search with many topics re 8500's and PCI PPC's of that generation.

Good luck, post back any questions. Attached is a drawing of an 8500 mobo the CUDA is in bottom left corner a square looking button.

[Mr Magoo]

Many thanks. Very helpful. With your information found the CUDA switch and actually it's not that difficult to get to it. You don't have to take the mother board off.

1. Lower the processor card retainer by squeezing together the two holding clamps to release the retainer and lower it away from the logic board.

2. Lay the computer on its side so that may gain access to the interior of the computer.

3. Remove the current processor card from the Processor Card Slot.

4. The CUDA switch is located directly inline with Processor Card Slot. In my 8500 the switch is an orange colour. I used the rubber end of a pencil to press on that switch. I could not hear or feel any movement. Assumed i had reset it.

5. Reinstall the processor card.

6. Move the processor card retainer back into place: it snaps into place.

7. Replace the case cover and tighten the four security screws.



It's not all that difficult once you understand where it is and how to easily get at it.

[rwm]

Did it help the situation?

If not what's happening with it now.

[Mr Magoo]

Resetting the cuda was not the answer.

The original Apple hard drive was a 2 GB scsi'd. A PC tech guy friend said he may have an old SCSI 2 GB hard drive.

Or on the other hand he also thought that with the Mac SCSI drive setup for this machine he could try removing the dead drive and attach the connector of the ribbon cable to the second drive and see if it will boot.

Here's hoping...

[rwm]

Or on the other hand he also thought that with the Mac SCSI drive setup for this machine he could try removing the dead drive and attach the connector of the ribbon cable to the second drive and see if it will boot.

I'm remembering something about SSCI that is making me think you need to have a drive on the last spot on that ribbon your talking about. - could be wrong there

I do know you need something at the end to set your ID and termination right. When I first learned about SSCI over 12 years ago it made no sense to me why I could not pull a good working hard drive from one computer and put it into another machine and nothing. I'm like why won't this work.

It took me forever to learn or understand SSCI ID and termination. I thought I had a page of "SSCI do's and don't's" but I can't find it or it in an AppleWorks format and that will not help. I'll look here on the Guru's threads and I'll post it here if I find some thing that might be of help.

[rwm]

ID:
First each device must be assigned an ID usually 0-7, with the startup or boot drive being 0, the CD ROM is usually 3, and the computer it self may use 7. The ID is changed by changing the little jumper pins on the hard drive.

Look on the drive it self some have diagrams or go to the vendors web site for a diagram. You can post your info and we?Äôll be Glad to help.

So decide which drive you want set as your boot drive and set it to zero 0. Set any other to something other than 0,3,7

Termination:

1: All SCSI chains MUST end on either a terminator or a terminated device.

2: No device other than the end device can have termination enabled.

3: No device should have termination power jumpers installed.

4: If you have an 80 to 50 pin non-termination capable adapter that drive MUST NOT be on the end of a SCSI chain since it cannot terminate the chain.

Termination is often set by jumper too.

Here are some good definitions and basic info on Apples site.

There are also some good tips, definitions right here.

I've got some company here now. I know theres are better posts or threads out there I'll search further if needed. What's your knowledge on SCSI ID and termination? Do you understand it or is it a confusion?

[Mr Magoo]

What's your knowledge on SCSI ID and termination? Do you understand it or is it a confusion?

zilch understanding and huge confusion at this time !

I;ve only worked with SCSI ID and termination by following manufacturers road map directions for connection of my Castlewood ORB and Syquest EZflyer external hard drives.

I still have both although the ORB is not working correctly as it used to. Today found this web info that may help me: http://www.macease.com/updated_info_on_using_the_.html .

Once again i really appreciate your efforts to help me by providing information and urls that help Mr Magoo and his friend All Thumbs.

[rwm]

Any luck with those links? Did you try your friends drive? If your friends drive has an operating system on it... it might work better at the end of the cable than that 2nd open spot.

Feel free to ask away anything... nothing a stupid question. What's happening with the computer now.

[Mr Magoo]

The 8500 still has a dead hard drive.

The ORB and Syqest ( EZflyer ) external SCSI hard drives are flaky these days at best. They worked great in their day but slowly they became unstable. However not sure they will help now because as best as i understand this I have to install a "driver" before a computer ( running OS 9 or less ) can "see" the drive. Since the 8500's main hard drive is dead that idea is out the window.

At this time I'm researching your information and trying to understand the instructions to disconnect the original 2 GB apple hard drive.

No word from my tech friend about locating a 2 GB hard drive although I have some concerns about his knowledge with Mac computers. His full time business is working with PC's.

[Damien]

SCSI hard drives should not need a driver though they will need formatted if they haven't been already. Not sure what an Orb drive is though. I had a Syquest drive back in the day and I don't remember it needing a driver but that's been a long time ago

[Mr Magoo]

Damien,


My mistake, it's actually called Castlewood Orb Drive and the drivers have to be installed in the host drive.

http://en.wikipedia.org/wiki/Castlewood_Orb_Drive

In your 8500 Damien is the original 2 GB hard drive still working ?

[yeungfeng]

As I recall there are two types of SCSI, with different numbers of pins. Plus I don't believe all SCSI Drives will work with a Mac, might run that past your PC buddy. A quick check of ebay shows there are some SCSI drive still out there. The Syquest drives are 135mb and I'll bet OS 9 won't fit on them. Here's a link to Low End Mac and they have lots of resources that you might find useful.

Good Luck!

[Mr Magoo]

The Castlewood ORB and Syquest EZfloyer (230 MB) both worked with my 8500 a long long time ago ( in the last century ).

I'm working on creating my own pruned down OS 9 or even OS 8 startup disk using the Syquest 230 MB cartridge. I believe it is doable because I have OS 9 and OS 8 startup floppy disks which are only 1.4 MB.

Thank you very much for the link to the Low End Mac. I never heard of that group. It looks very interesting and promising for my interests and requirements at this time.

I have a small collection of power macs and am going back into time by working again with pre Mac OS X. It would be great if I could revive this 8500/G4 ( Sonnet processor ), with USB ports and FireWire ports installed, and RW CD burner internally installed.

[yeungfeng]

Oh I have an earlier model of the Syquest that is 135mb. I had forgotten that they made another model. I did a little search and found this page, finally, on OS 9. But back then one could fiddle with the OS and make in take up less space.

Gosh it's been so long since I've addressed these kinds of things, I kinda forget. I'll keep thinking on it.

[Mr Magoo]

Gosh it's been so long since I've addressed these kinds of things, I kinda forget.

That is partially my reason for going back in time as i refer to going into OS 9 and prior.

That Apple page on OS 9 makes me wonder if perhaps i should remove the Sonnet G4 card and replace it with the original process card. Perhaps that's the main reason it will not boot up from an apple install CD.

What say? Remove the Sonnet G4 card and replace the original card ?

[yeungfeng]

As I recall if you press the CUDA switch it will revert the Mac to the original firmware and thus the Sonnet's firmware will be gone. So I would say yes and reinstall the original processor. In theory you should be able to boot from your external drives and or your install CD.

Once you get it up to 9.1 you could download the drivers for your Sonnet G4 from their web site and reinstall the processor. If you have any other cards in the 8500 you should remove them as well and follow the same process of installing the drivers.

I'd also suggest changing the battery as it is surely dead. It keeps all the information, like date and time, and is a real pain if it doesn't work.

[Damien]

I don't think the cuda changes any firmware. Only a firmware updater will do that and it's very difficult to go backwards on firmware, in fact I don't think I have ever seen one go backwards.

As always though I could be wrong, lets ask Rick... Rick? RICK! (dangit will someone wake him up..)

[yeungfeng]

Damien you are most likely right on the CUDA. There's a great deal of information, from long ago that seems to be pretty vague for me. I might need my brain defragmented.

Sssssssshhhhh, don't wake him. He REALLY needs his beauty sleep.

[ricks]

He woke me….

CUDA removes battery power from the PRAMs and NVRAM and allows them to go back to default settings. Does not rewrite firmware, although the PRAM and NVRAM modify the behavior of the firmware as they are accessed to set up boot behaviors.

R