Mac Classic spawned to life #marchintosh 2021

Check out the video on YouTube: https://youtu.be/5vdGbsNMdXM

I was encouraged to attend the #marchintosh 2021 tag on YouTube which is about Apple Macintosh in March. I don’t have much experience with the old Apple computers, but I have one 1990 model Macintosh Classic that I’ve had for several years, that did not work. It produced an image (floppy icon) on the CRT, so I knew the motherboard and the logic board worked somewhat.

I have made a couple of attempt to make it boot from the HD or floppy drive before with no luck, but now I wanted to give it another go.

This time I took out the HD and the floppy drive and inspected both. The HD was gone. It was worn, and had leaked something inside so I considered it a no-go, but I still tried to make it work by cleaning everything and tested it. But no luck with that.

Then I went on with servicing the floppy drive. Apple used special floppy drives with eject mechanism, not common in other machines at that time like the Commodore and Atari’s which had manual eject mechanism.

So I cleaned it really good with alcohol and then lubricated the moving parts.

This was obviously what was needed because when I connected the floppy drive to the mac, it actually was able to boot from the System 6 floppy diskette I had 🙂

This was of course a happy moment because I had never seen this machine booting since I got it 6-7 years ago. So I tested it a bit. Unfortunately there was no sound from the machine. I tested also the 3.5mm audio output jack, but no luck. That will be a task for next time.

Then it was time to try out another HD since the one in the machine was gone.

I got hold of a 1Gb SCSI harddisk with the correct 50-pin connector and the correct molex power connector. The original was a 40 Mb drive, so it was a big difference. It was all looking good, but the HD SC Tool on the system 6 floppy I have, would not even detect there was a SCSI drive connected. So I researched a bit and found that Apple did some clever stuff to only allow Apple’s own drives to be used, so only drives with an Apple specific ID is detected by the HD SC Setup Tool.

So what to do then ? The chance of finding a genuine Apple 40Mb SCSI HD is slim now. But there is always a solution. I found a “hacked” (patched) version of the Macintosh HD SC Setup program. This will allow for installing non-Apple HD drives. Just search for HD_SC_Setup_7.3.5_Patched.bin if you want to find this tool.

I used the MacDisk program on my Windows 10 computer with a “modern” UBS-based floppy drive that I have. This program lets you format floppy disks as mac-disks, and then copy files or disk-images to the floppy. You can find it here: https://www.macdisk.com/

Versions 7 et 8 of MacDisk

The MacDisk program has some issues, but it worked out OK. I could copy games and disk images to floppies and they worked on my Mac Classic.

Then I ran the patched HD SC Setup from the floppy.

Then to my surprise the program actually detected the drive

My hopes where high now. I ran the Test and it completed successfully, and I could hear the drive was working. Then I ran Initialize, but the initialize failed.

After that I tried several things. I changed the SCSI device ID with the jumpers on the drive, and other different jumper settings. The program would see that it got another id, but still would not initialize the disk.

So eventually I gave up and called it a fail. Maybe the 1 Gb drive is too large, maybe it is faulty, maybe the machine is faulty, I don’t know.

One thing I do know, I learnt a lot from this. Maybe the next time I pull this machine out I can get it to work with a harddisk.

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