Thank you @aBc for responding. I have been working my way through some of that information. Of course I was kind of hoping there might be an answer along the lines of, "90% of the time it such and such dohickus that is bent out of shape." But reality tends more along the lines of fiddling around with a half dozen or so minor hard to see, hard to get right tweeks that are needed to get things working.

I did notice the pictures until I logged in to reply. What is the logic behind requiring a login before displaying pictures? In any event thanks for the suggestions and the pictures.

The drive is working fine and is the one from this PB G4. This unit was a lucky and rare find. From what I can tell from files on the hard drive it was in service for about 6 months before being stuck on a shelf and abandoned. The battery was stone cold dead, but took a full charge having ~80 cycles on it and now with a full charge it gives ~4 hours run time. There is not a scratch or dent on it. There was a missing keycap and the unit was filthy (from sitting for years in an attic?) And now I have been using daily.

Ultra-Fast SCSI (narrow FAST20), with theoretical speeds up to 20 MB/s. However, real-world performance tends to be around:

Read speeds up to ~18 MB/s

Write speeds up to ~11 MB/s

thats even faster than BlueSCSI v2
Supports Ultra‑SCSI FAST20 sync up to 18 MB/s (with overclock)

Pre-release of firmware for BlueSCSIv2 from July 2025 opens up similar opportunities. There is information about the tests here.

i love it, after restoring apple floppy drives, my tibooks need to have their cdroms serviced as well,

they all sort of work mechanically

No dings or external dents in the outer case, especially near the right internal mounting point or along the front of the case where drive ejects? (Had one here with a fairly severe right corner dent that changed the position of that right front mount just enough to interfere with eject.)



Other than that, a very sparse light coating of lithium grease applied to the drive’s internal metal pivot arms and other moving parts can do wonders.

If the keyboard being properly installed interferes -  that suggests the drive is somehow “higher” or otherwise out of normal position (from other possible damage?) for some unknown reason or another.

Is it an original optical drive or a replacement of some sort?

All red-dotted tabs correct and no other obstructions (rubber pads, etc.) to interfere here on the bottom side of the top?

Thanks for the link, J. Great to see (and hear) the “old man” being creative… even if he’s in his pajamas originating from the new Inter-dimensional Retirement Center for Forum Masters.

And yes, an added ripping guitar solo break might have just set the video completely on f-f-fire!

Of course, I’m mostly kidding here. But honestly, big thumbs up!

https://www.youtube.com/watch?v=aevNQBEawPQ

You owe us a guitar solo, DieHard!

Strangest Valls ever!

I have tried editing nvedit but when I start and press ALT, only the OSX partition appears

Code: [Select]

nvedit

Code: [Select]

dev /cpus/PowerPC,G4@0
80010201 encode-int " cpu-version" property
device-end

dev /pci@F2000000/mac-io/i2s/i2s-a
" screamer" encode-string " compatible" property
device-end

Press CTRL + C to exit the NVRAM editor.

Code: [Select]

nvstore
setenv use-nvramrc? true
reset-all

If this works, then copy it into a script.

If you wanted to wait, I might try modifying one of the ROMs tonight (but no promises). I don't currently have any machines to test with right now

Wow, thanks a lot! I'll try, but I don't know if I'll be able to write a script that runs at boot time. I'm not sure how to do this.

If you could make a modified ROM, that would be perfect! I can wait; there's no rush. If I can provide you with any information you need about the iMac, let me know how I can get it and I'll help. I guess using a 7447 instead of a 7445 doesn't change anything.

Thanks!!!

Bump. Again this is free and very close to being taken to e-waste.

Shipping would only be about $20-30 across Australia.

Hi Indibil,

Congrats on the upgrade, that's a fast machine!

I haven't had much to do with the unsupported installations for a while, but from what I remember a lot of the later G4 models have an unsupported sound device, and require the "screamer" fix to trick it into thinking the current device is compatible. This does require using Open Firmware (at least once).

My suggestion would be to follow the steps in that post with the "screamer" fix. When it boots you can write a script so you don't need to deal with Open Firmware every time (guide also referenced in that post). If you write a script with the Open Firmware commands, you only need to set the boot device to the script in OFW and it will run the commands automatically.

I've been planning to look at modifying the Mac OS ROM to run some of these commands, but I haven't had enough time recently.

A while ago I tried messing around with OFW to bring graphics support to the unsupported iMacs but was unsuccessful - a post you may find interesting/might want to do some experimenting with:
https://macos9lives.com/smforum/index.php?topic=7054.msg54720#msg54720



In summary, boot into OFW and enter these commands as a test. It's likely you need to apply the "screamer" fix which I don't think is present in any of the Mac OS ROMs contained in the ISOs.

nvedit
dev /cpus/PowerPC,G4@0
80010201 encode-int " cpu-version" property
device-end

dev /pci@F2000000/mac-io/i2s/i2s-a
" screamer" encode-string " compatible" property
device-end

Press CTRL + C to exit the NVRAM editor.

nvstore
setenv use-nvramrc? true
reset-all

If this works, then copy it into a script.

If you wanted to wait, I might try modifying one of the ROMs tonight (but no promises). I don't currently have any machines to test with right now