Power Mac 7220: Optical Drives
The Power Macintosh 7220 was built cheap and used off-the-shelf PC hardware, including IDE CD and harddrives. Due to this, upgrading the CD drive is relatively easy... or it seems it would've been... when IDE CD drives were popular! Nowadays everything is SATA and so finding a good IDE CD drive can be difficult. You'll find them on eBay, but they'll be marked as vintage and people therefore think they can raise the prices.
Fortunately, in one weekend I managed to acquire a grand total of 6. I bought 2 on eBay (a standard PC version and then another since it was an actual Apple model) as I was sick of not finding any, but then stumbled across another 2 at Trash and Treasure (Australia's version of Flea Markets or Swap meets) the very next morning. The following post is an effort to detail the pain and suffering of finding out how (in)compatible the drives were.
LG CED-8080B
I actually found this at a thrift store last weekend for AUD$5. Initially, installed into the Mac with cables connected, it stopped the entire machine from booting. It was about to be shown the bin... but I chose to test it again, once I'd worked through the rest of the drives, and the bloody thing decided to function.
It wouldn't boot the Mac OS 8.0 CD that I had burned on Windows (but this seems to be a common trend... note that the CD image is now deemed unbootable!) As another test, I installed Toast 4.1.3 and found a blank CD-R. Using Toast's "Disk Copy" method, I created a new temporary CD volume and then dragged the System Folder over from my main startup disk. Toast burnt all this to the CD (with the bootable flag) and the CD booted!
Pioneer DVR-106D
Very plain-looking Pioneer drive. Expecting good things from a quality manufacturer.
Again, it wouldn't boot the image burned via windows. I therefore tried something different: I imaged the burned Mac OS 8.0 CD to the desktop, mounted the image and then attempted to re-burn the image to a new blank CD with the bootable flag set. Unfortunately, I couldn't actually successfully burn a CD with this drive. No configuration or speed setting (buffer-underrun protection included) would work!
Another point: ejecting the tray saw it get sucked straight back in again... a fault of Mac OS or the drive itself? If you were quick you could snatch the disc out.
Pioneer DVR-108
Quite similar to the previous Pioneer, this is a very plain looking drive. Based on the previous drive, my hopes weren't so high!
This drive also failed to burn every CD I tried. Even on standard settings (16x), it threw buffer underruns. Switching on the buffer-underrun protection did nothing to help. Burning at lower speeds (all the way down to 1x) with underrun protection still failed miserably.
Don't use Pioneer drives with old Macintosh machines. Seems that it takes too long to spin up and the machine fails to have the data ready?
At this point I switched back to the LG CED-8080B that I knew worked... just to make sure my process of disk imaging was stable. It happily burnt the disk image! Of course, on reboot the Mac just showed a question mark. It had no intention on booting my 'bootable' copied-twice ISO.
Note that, once back in the OS booted off the HD, I could still happily use the installer on the CD. It just wasn't bootable.
LG GSA-4167B
This one is listed as a Super-Multi. I'd usually be happy with this level of functionality, but the above results indicate that the Power Macintosh itself may not be able to cope with a drive that can spin too fast.
Either way, it still is a really nice drive... smooth, quiet and fast. The best part is that it burned the CD with no issues!... but it proved that my CD burning idea was incorrect. You cannot convert a non-bootable ISO burned under Windows into a bootable ISO this way.
Note that this drive does not open with the case on. The tray face is too large to fit through the space provided in the front panel of a Power Mac 7220 case! This is sad.. it's the best drive of the bunch, and I didn't feel like hacking it to make it fit!
Apple GCC-4480B
Smooth drive. Happily imaged an 8.6 CDR ISO in a matter of minutes. Note that it does not have a drive activity LED on the front.
The image was then burned back to a CDR with the bootable flag and the image booted! The flashing disk with question mark showed up for a split-second and then it convinced itself to boot!
Feeling motivated, I used this drive to try and re-build the Mac OS 8.0 ISO into a bootable CD, but the drive also refused to boot it. Turns out that ISO itself is to blame?
This drive also doesn't fit correctly behind the face of the Power Mac 7220 case. Due to the missing front plate on the drive, the eject button doesn't mate and therefore the drive is rendered useless when the case is put back together.
Apple CR-583-B
This is the original drive that came with the machine. This has a little sticker over the eject button (but the button still works) and an activity light which is obscured by the front case.
This drive happily booted the OS 8.6 ISO that was re-bootable'd using the process above. This contradicts my initial impressions of "not being able to boot a burned CD", as ... well ... it does boot them. You just need to make sure the burned CD is 'correct'.
Of course, this drive is not a recorder... hence why Toast was telling me that no recorder was found. I even rebooted the machine to find the recorder... I can assure you that rebooting did not turn it into a recorder!
Which Drive?
After trying out everything above, I had to settle on a drive. I didn't want the original as it didn't have the 'tabs' to hold a CD in when the drive is mounted vertically. I also wanted to use an Apple drive, but the one's I had wouldn't really work with the case or weren't a burner. Instead I chose the black LG and modified it's tray face-plate to fit through the Power Mac's front fascia. This required a little filing on the ends of the tray.
In the end, it works like a charm!