Trouble booting a Classic

[admford]

A couple of years ago I bought a used Classic at a computer expo near my home, but never had enough time to start messing around with it. Anyways, finally today I pulled it out of storage to see if it works, but I only get a gray screen and a mouse cursor on it. I've tried booting via Command-Option-X-O, but it's like it doesn't respond to the keyboard.

I've checked the inside and the mainboard seems to be in good condition and everything is seated nicely. Also noticed it had a 40MB hard drive and 2MB of additonal ram (not bad for 20 euros a couple years ago).

Anyways, I'd like to get this computer working again, but really have no idea where the problem may be. At the least, I think it might be the keyboard that's broken (but the mouse, which is connected to the keyboard's ADP port, works).

 

[MultiFinder]

When are you pressing down Command-Option-X-O? If you haven't already, hold down those keys while the machine is off and, while holding them down, flip it on. You need to be holding those well before the blinking floppy screen. People usually suggest holding them down right after the startup chime, but I've always found it easier just to get them down while the little bugger's off. If it doesn't work, then there probably is something wrong with your keyboard.

 

[Patrickool93]

Just a guess, but try a bootable floppy in there, cause it *might* be finding a corrupt system folder, which it *might* try to boot, possibly stopping booting, and just hanging there.

 

[admford]

Just a guess, but try a bootable floppy in there, cause it *might* be finding a corrupt system folder, which it *might* try to boot, possibly stopping booting, and just hanging there.

Had the notion that that might be a problem, so I checked that the floppy drive doesn't have any disks in it. And also I removed the hard disk just to be doubly sure.

I managed to boot using the command-Option-X-O combination when turning it on (thanks for the tip MultiFinder17). But I wasn't able to do so after I re-installed the hard disk. From the looks of it, it seems that the hard disk might be the culprit, since I hear it running, but I don't think that it's actually functioning correctly. I'll have to find a boot disk for the Classic and try to boot from it (first get a floppy drive for my MacBook to write the disk) to rule out any other components.

 

[equill]

You didn't mention either replacement of the 3.6-V lithium half-AA PRAM battery or starting up with one of the four-fingered salutes. If the battery was already of pensionable status when the Classic went into a cupboard, it is beyond that now. Better no battery than an exhausted battery, and best a new one.

Do you hear or feel the HDD spin up? If it doesn't, you'll need an alternative start up volume with a blest System Folder on it and valid boot blocks pointing to the folder. A Disk Tools floppy, or a full system (say a floppy disk containing System 6.0. 8) , will relieve you of trying to coax 6.0.3 out of ROM. If you haven't such a floppy (and you can download 6.0.8 here), in the meantime you should, if the HDD is spinning up, hold down command-option-p-r immediately after the POST (startup) chime, and release those keys only after the third extra chime.

This will reset the scrambled PRAM settings (which include the advice to Start Manager to look for an HDD at SCSI 0-0-0) resulting from a defective or absent battery, but will profit you only if there is a valid System Folder on an active drive at 0-0-0. The advantage of a boot floppy is that it bypasses possible SCSI woes because the FDD is polled first for a bootable System. A Disk Tools floppy will enable you to run Disk First Aid and HD SC Setup over the HDD, supposing that it can be mounted. If you can mount the HDD, you can check visually for a bootable System Folder.

de

 

[MultiFinder]

Beofre you run off and get a floppy drive for your MacBook, check one thing.

Boot the Classic with the key combination, and then stick a floppy in the drive. If it pops up a little message about the disk being unreadable, go ahead and format the bugger. If it does that and you see the disk pop up on the desktop, then you know that you're floppy drive is working (this is always a good thing to check, because these seem to die off regularly).

Once you have done that, open up the "Boot Disk" (the little floppy icon with a chip on it) and drag the System Folder that you'll find in there onto the floppy that you just formatted. After it's done copying, shut down the Classic. It should spit the floppy out for you. Stick it back in and then flip the machine on. If it boots off the floppy like it should, then this confirms that you have a fully functional floppy drive and should be alright to go ahead and get one for your MacBook so they can talk.

Not only that, but this'll give you the illusive bootable floppy

 

[Patrickool93]

Classics are awesome floppy making machines

 

[admford]

Ok, i've tried to zap the Pram, but it won't do anything. No beep saying that the pram values have been reset (other than the first beep when it turns on).

From that, it seems like it might be a problem with the PRAM battery. Tomorrow i'll probably look to get a new one to replace it, and also try to boot from a floppy that i've got lying around here. I managed to get some software for windows that lets me make a boot disk for my Mac, so I shouldn't have any problems if I write the floppy from my Toshiba Libretto.

 

[bluekatt]

Classics are awesome floppy making machines

..mine isnt

 

[admford]

Well I followed Multifinder17's advice and managed to make a System 6.0.3 boot disk. The good news is that my Classic's ram is 4MB! the bad thing is that the classic won't boot from Rom or floppy with the HD connected to the SCSI port.

I still have to change the battery just to be sure, but it seems more and more that the culprit is the hard disk. I'll be keeping an eye on ebay for some old SCSI hard disks that would work with the Classic. Though, I do kinda wonder what is the largest hard disk size that it can accept (in MB). The current one is the standard 40MB model, but i've found a ton of 40, 80, 480MB SCSI hard drives on say in Germany (through ebay). But they're not verified to work or have a possibility to return them if they don't.

 

[pee-air]

You should be able to get a decent SCSI hard drive for next to nothing. Especially the smaller capacity hard drives. I'd check a couple of things before I give up on the drive though.

Start by making sure that it's not the SCSI cable that is causing you problems. You can do that by trying the drive in another machine. Or, you could simply try a different SCSI cable on your Classic. You might also want to check the SCSI ID setting on your drive to make sure you're not having an ID conflict. Only SCSI ID's 0 through 6 are available for use by devices. Make sure your drive is not set to use ID 7. This is the SCSI ID that your Macintosh computer uses, and will cause conflicts if your drive is configured to use ID 7 as well.

I trust that you've already checked to make sure that the logic board end of the SCSI cable is firmly seated in its 50 pin socket?

Finally, if you determine that the drive is in fact the culprit, I would avoid getting an overly large drive for your Classic. Simple fact of the matter is that a compact Mac with only four megabytes of RAM will not be able to run probably 90% of the Macintosh software that is readily available. So spending a few extra bucks on a drive that will likely never be filled to capacity is probably not worthwhile. You may also have some heat and power issues to contend with if you stuff a large capacity drive in there. Though I'm not entirely certain about that last bit.

 

[equill]

Further caveats about SCSI HDDs and the Plus/SE/Classic 68000 Macs may be found in these threads:

http://68kmla.org/forums/viewtopic.php?t=1606&highlight=interleave

http://68kmla.org/forums/viewtopic.php?t=1485&highlight=interleave

The re-use of the 68000 in the Classic was three years after the SE, and separated by the release of half-a-dozen 68020/68030 Macs. Twenty-odd years later not everyone remembers that even SCSI had its quaint little ways when it was new. The interleave factor of 2:1 for HDDs in the SE was a direct function of its slow SCSI port, which is another argument for not exceeding 120-160MB when you search for another HDD for your thinly-disguised SE called a Classic. It should, however, be using an interleave of 1:1, but only at a blistering 1.25MB/s.

Jumpering of the drive for SCSI ID may not offer much difficulty. Early Quantum HDDs (amongst the commonest, especially in 40-80-120-160-240MB sizes) did not encourage much intervention by users. There was only one ID available, viz 0-0-0, and termination was enabled/disabled with removeable in-line resistor packs. Later Quantums did have the A0-A1-A2 jumper positions for SCSI ID, and a TE (termination enable) jumper position, but termination power still had to come from the SCSI bus.

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[pee-air]

Jumpering of the drive for SCSI ID may not offer much difficulty. Early Quantum HDDs (amongst the commonest, especially in 40-80-120-160-240MB sizes) did not encourage much intervention by users. There was only one ID available, viz 0-0-0, and termination was enabled/disabled with removeable in-line resistor packs. Later Quantums did have the A0-A1-A2 jumper positions for SCSI ID, and a TE (termination enable) jumper position, but termination power still had to come from the SCSI bus.

de

Some of the earlier drives did not use jumpers at all. Instead they had DIP (Dual Inline Package) switches on the drives controller board. The use of jumpers came later. Probably a cost cutting measure, but who really knows? I do find it rather ironic that setting the SCSI ID became more difficult with newer drives though. i.e. jumpers on often poorly labelled pins versus DIP switches which were easily distinguishable and much easier to fiddle with.