This was rather unexpected, but this auction for a loaded Macintosh Plus had shown up, and it was shipping local, and very cheap for what it was. It included the larger keyboard, original mouse, and an external 20MB hard disk.

Sadly, the hard disk is dead. And not like dead dead, but dead dead dead! After I freed the disk from the external enclosure, and tried to power it on, stand alone, the PSU refused to start as the disk has a hard short in the board somewhere. And I can’t say that I’m all that surprised that a hard disk from 1989 is broken. I’m more surprised that someone was using this in 1989 and didn’t take the plunge and upgrade the machine to the full 4Mb of ram.

Anyways I have this chunk of plastic and glass on a desk, but I can’t do a thing with it. I’ve heard of various SCSI emulators out there, and decided to go with a bluescsi v1 with a DB25 interface as they are generally cheaper, and the Macintosh Plus isn’t exactly all that fast so the effort of the v2 is mostly lost.

Documentation on the bluescsi is scant, but it seems that a diode needs to be soldered onto the Macintosh Plus motherboard to enable bus power, so you don’t need an external USB power source. I’m a bit worried about opening up this thing as I’ms suspecting the plastics are a log weaker than they look, so I opted for just using a USB cable to power the device.

Anyways let me cut to the chase, I have an 8Gb Micro SD card that I formatted ExFAT (the documentation says Fat32 will work, but I found it might work once, but it’ll definitely never work after a reboot), with a single file emulating a 100Mb hard disk (Luxurious!). I named the file simply ‘HD10_512.hda’ which specifies it’s a hard disk, SCSI ID 1, target 0, 512 bytes/sector and it’s a ‘hda’ image. It’s what the Bluescsi want’s so don’t fight it!

To prepare the virtual hard disk, I used Cockatrice III, since the Macintosh Quadra 800 emulation includes SCSI, which let me create a raw disk image, partition it, and format it under MacOS 8.1. The real trick was installing the operating system.

I first tried MacOS 7.0.1, but it would boot up greeting me with the error that needs more than 1Mb of ram. I tried installing a MacOS 6.0.8 manually, but it crashed saying the system folder was corrupt, and then it just went empty disk mac on further boots.

I’m not sure what the problem was, it’s possible it was the filesystem on the card, or some other issued with the Macintosh, I have no idea.

So I broke down and ordered a pre-installed diskette with MacOS 6.08.

I booted off the diskette, and amazingly the floppy drive worked! And in about a minute I had booted up, and it saw the hard disk! I dragged the System folder over the hard disk, and rebooted, and yeah it booted right up!

Obviously, the next step will be to get a proper screwdriver to open this thing, figure out how to discharge the CRT so I don’t kill myself, and add some additional RAM. I know it’ll be slow but I do want to see MacMiNT run on this thing! Maybe I’ll find/order the needed diode and make the DB25 bus powered eliminating one cable.

A long long long time ago I did own a Macintosh Plus, with 4Mb of RAM, although I mostly used it as a terminal, since it powered up quickly (it was the mid 90s!) and doesn’t take up that much space, so maybe I can slave it to an ESP32?

**UPDATE

I had been using some generic 8GB microSD card on this, and while it seemed mostly fine on the Macintosh Plus, I had since managed to score a Performa 6400. I had been using this Kingston generic 8GB card, and it had frequent timeouts writing/reading on the Performa. As a matter of fact if the SD card was plugged in at powerup with an ISO image it would crash the Mac.

Kingston SDC10/8GB 015FCT C08G… no good!

I scored this SanDisk Extreme 32GB for £15. A bit pricy but it turns out totally worth it!

£15 SanDisk Extreme!

Not only does the Performa not crash with an ISO image but it’s pretty darn quick! Well worth the purchase as all my weird issues seemingly just disappear!

So yeah, lesson learned, don’t go cheap on flash.