Can Color Classic I & II boot from SCSI CD-ROM?

[ried]

I have a Color Classic with an Apple 300E Plus SCSI CD-ROM drive, which is set to device ID #3 and has active termination on the lower SCSI port.

I can not get the Color Classic to boot from a CD (System 7.6 or 7.6.1 Installer CDs) and am puzzled. Behavior is the same with both the original Color Classic logic board and the Color Classic II logic board. Just a flashing question mark on the floppy disk image at startup.

I've tried Command + Option + Shift + Delete + 3 at startup, but that doesn't seem to have any effect.

The Apple 300E is confirmed working on another Mac. Any ideas?

 

[jajan547]

Try taking the jumper off of the cd rom.

 

[MacKilRoy]

You can boot almost every Mac from a compatible CDROM drive.

Did you verify you have it hooked up correctly and the drive is properly terminated (ie: do you know the terminator works)? Also, are you booting a PowerPC system CD or one that you made ?

 

[CTB]

Try holding down the “c” key straight after the startup chime.

 

[MacKilRoy]

Just thinking here: MacOS 7.6 and above requires 32 bit addressing to be enabled. If the PRAM battery isn’t present the system defaults to 24 bit, which isn’t compatible. On a hard drive when you boot 7.6 and above it starts, enables 32 bit memory, and reboots. Would it do that with a CD (non writable volume)?

 

[ried]

Thanks guys. My suspicion is that the SCSI2SD inside with a 32GB SD card is causing problems on the SCSI bus. I'm going to swap it out for a 2GB card and continue investigating. 68k Macs are new to me, and I'm probably making a bunch of mistakes here.

Will report back.

 

[ried]

It works. I'll be damned. It's really amazing just how different these 68k Macs are compared to the PowerPC G3 & G4 machines that I'm used to. SCSI termination and quirks, System 7, HFS (rather than HFS+) and how it's impossible for a modern Mac to read/write that format. My brain is tired but I learned a lot.

The reason mine would not boot is because I erased the SCSI2SD's memory card and thereby its SCSI configuration. Took that out, reset it. Used the "dd" utility to write a 2GB SD card in the appropriate format, reinstalled. Booted into the 7.5.5 minimal system, installed the Apple CD-ROM driver, then rebooted and tried to install 7.6.1 from the CD. Enabled 32-bit memory addressing. Discovered that the 7.5.5 image uses a Mac Plus Gestalt ID, so had to reset that to Color Classic II and reboot to begin the 7.6.1 install process. Now it's underway.

Fun to learn how to use these old machines 30 years after they were new. This is a lot less intuitive that anything Apple made post-1997, IMHO.

Last mystery to solve: I bought an "Atari tt co-processor motorola mc 68882 fn33 - 33 mhz fpu arithmetic processor" on eBay, hoping it could plug into the Color Classic II motherboard and pair with its 33 MHz 68030. It physically fits, but the machine will not start when it is present. No chime, nothing. I assume that's because it was made for Atari and the Mac part is somehow different?

 

[ried]

Well, shoot. Yes, the CD-ROM works when it boots from the internal hard drive and the CD-ROM driver has been installed.

I can not, however, get the machine to boot from the CD-ROM drive itself. Same SCSI ID and everything, but the Mac doesn't want to talk to the Apple 300E Plus unless and until the OS boots and the driver is loaded.

What am I doing wrong? I'd really like to boot this thing up from a CD.

 

[Johnnya101]

I know for a fact a CC I can boot from a CD drive, I have done it before. Hold down the C key when you start it. Shouldn't the ID be #2, unless you have other things chained up? HDD #1, CD #2?

 

[mdeverhart]

It doesn’t matter what ID the devices have, as long as none of them conflict (remembering that the Mac is ID 7). It’s pretty typical for Macs to use 0 for the internal HD and 3 for a CD-ROM (either internal or external), though that’s just convention.

 

[ried]

Internal HD is using 0, while the CD-ROM is using 3, and the Mac ID is 7. Still trying.

 

[mdeverhart]

How did you burn the CD? And what image did you use? It’s possible it wasn’t burned in a way that is bootable.

 

[mikes-macs]

I have best luck using Toast to make burnable CDs from Mac Volume.

 

[Johnnya101]

I rarely do anything SCSI, didn't know that info, thanks for sharing.

OP, IF you did burn the CD yourself, my Apple 600e will only read up to a disc burned at 4x speed or less. Not sure how the 300 is. Of course, if it's an original it will just work.

Also, when booting and holding c down, does the drive making any sounds like it's searching?

 

[ried]

I'm using this 7.6 toast image (among others), which was burned to CD using toast on my Mac Pro with no errors and verification checked out. It looks normal, and shows up in Finder after booting into the Mac OS 7.5.5 minimal drive after the CD-ROM driver is installed. It should boot, but the Mac doesn't want to talk to this drive unless it's already booted into the minimal system and the driver loaded.

When holding c down during startup, the 300e's LED indicator will briefly flicker from green to orange to indicate it's attempting to read the CD-ROM, but it quickly gives up and boots from the SCSI2SD in the hard drive bay anyway.

 

[mikes-macs]

Look to see if the System Folder is blessed on the CD just for the heck of it.

 

[MacKilRoy]

I'm using this 7.6 toast image (among others), which was burned to CD using toast on my Mac Pro with no errors and verification checked out. It looks normal, and shows up in Finder after booting into the Mac OS 7.5.5 minimal drive after the CD-ROM driver is installed. It should boot, but the Mac doesn't want to talk to this drive unless it's already booted into the minimal system and the driver loaded.

When holding c down during startup, the 300e's LED indicator will briefly flicker from green to orange to indicate it's attempting to read the CD-ROM, but it quickly gives up and boots from the SCSI2SD in the hard drive bay anyway.

I have a theory: files uploaded to Macintosh Repository get modified upon upload by their system, and comments are added that attribute the file to Mac Repository. I suggest you try and download this same image from another site, and then burn it and try again. I know it might waste a CD but it could be what's preventing it from booting. If the Iso was modified, the boot sector may have been stripped out.

 

[ried]

I think you may be right. After burning several 7.6 and 7.6.1 CD image files and failing, I went ahead and purchased an original 7.6 retail CD on eBay.

In the meantime, I ran a SCSI chain of Mac > ZIP 100 > 300E Plus CD-ROM. Booted into the Mac, ran the CD's 7.6 Installer and installed 7.6 onto the ZIP disk.

Then replaced the CD-ROM with a SCSI2SD v5.5, so it was Mac > ZIP 100 > SCSI2SD v5.5. Copied the ZIP disks content to the SCSI v5.5. Then removed the ZIP 100, so it was Mac > SCSI2SD v5.5.

Booted using SCSI2SD v5.5 and copied its System folder to the Mac's internal SCSI2SD v6. Removed the SCSI2SD v5.5 and now it's booting 7.6 from the internal SCSI2SD v6.

What a pain

 

[Johnnya101]

What speed did you burn it at?

 

[ried]

It burned at whatever the Mac Pro's variable drive burns at. If Toast verifies the burn at the end of the session, and it's therefore bit-for-bit perfect, why does the write speed matter?