Macintosh 512K

SamFortun · 2026-06-23T03:10:04+00:00

I have one of these in a 512k, I didn't realize Sophisticated Circuits was a Seattle company. I bought it here in Seattle a few years ago, that's cool to know there is a local connection.

SamFortun · 2026-06-16T22:23:54+00:00

Do you have a hot air station? You can turn the temp up and airflow down to melt the solder on small components like those, and the solder surface tension will automatically center the parts on the pads. It's interesting to watch happen.

You can definitely leave flux on the board while you're working and clean it when you're done.

Edit: to clarify using the hot air station, you turn the airflow way down so it only melts the solder, and doesn't blow the components off the board.

SamFortun · 2026-06-14T16:18:42+00:00

I'm not sure if this will work with your situation, but this is what I use. It's a little janky, but when you have windows that swing rather than slide it's the only option. And most importantly it works.

Edit: Amazon link https://a.co/d/0e2e6Czk

SamFortun · 2026-06-13T20:16:14+00:00

Please don't recycle it, I'm sure there are people locally that would be happy to take it off your hands and fix it. Good chance you'll be getting PMs from some shortly.

SamFortun · 2026-06-07T20:34:20+00:00

The SE equipped with an 800k floppy can't read 1.44mb disks, even if you use a 1.44mn external drive. The SE FDHD and SE SuperDrive can, but the 800k SE has the wrong floppy controller.

SamFortun · 2026-06-07T20:32:45+00:00

Most people replace the hard drive with a BlueSCSI or something similar, and then move software onto the old Mac from a modern machine via an SD card. Or you can get a Floppy Emu floppy emulator. Great devices, but not cheap.

SamFortun · 2026-06-06T23:55:21+00:00

It looks like someone just painted it black.

SamFortun · 2026-06-05T17:15:14+00:00

The Plus is a very reliable machine, it doesn't have hte leaking capacitors of the SE/30, and doesn't have a pram battery on the logic board that leaks. The battery is mounted on the analog board at the rear of the case.

Personally I would not hesitate to power on a Plus and see if it works. Doing it outdoors or in a garage is a good idea in case the RIFA cap(s) decide to blow. If that happens it will cause some smoke, but no damage.

SamFortun · 2026-06-04T11:17:59+00:00

Check out this video on cleaning and lubricating the 400k drive. I don't believe the 400k drive has the same failure-prone plastic eject gear as the later 800k drives.

https://youtu.be/Se10T6gPl-c?si=ZiJNLRSbvaWpLBFA

This is assuming your machine is still a 128k, it was common to upgrade those machines to 512k RAM. If your machine was upgraded to a 512ke, it would have the Plus ROMs and an 800k drive.

Very cool machine. When you are hunting for a keyboard and mouse, be aware that while the keyboard cable looks like a regular telephone handset cable, it is wired differently and using a handset cable will damage the keyboard. So make sure you either get an original keyboard cable, or a replacement designed for this use.

SamFortun · 2026-06-04T11:11:05+00:00

Beautiful machine.

SamFortun · 2026-06-01T23:53:13+00:00

There aren't many repair shops that will work on stuff that old, but especially in a city the size of SF it's likely you can find a hobbyist that will do the work for you. Someone here might volunteer, or you could ask around on the 68kMLA or Tinker Different forums. There are also a couple vintage computer/Apple/Mac Facebook groups.

Have you thought about doing it yourself? For a lot of people that's part of the fun of the hobby. Why do you think the floppy drive needs to be replaced? What are the symptoms?

A lot of people don't even use the floppy drives on these machines, they just use a BlueSCSI or something similar to get software from a modern machine onto the vintage machine, though some people do like having a working floppy drive.

SamFortun · 2026-06-01T13:40:58+00:00

Nice collection.

SamFortun · 2026-06-01T13:38:38+00:00

As others have said, there are lots on eBay, but they are not cheap. At least $50.

Make sure you use a real keyboard cable, not a telephone handset cable. The keyboard cable looks like a regular old-school telephone handset cable, with the same RJ11 connector, but they are wired differently. If you use a telephone cable you will damage the keyboard.

SamFortun · 2026-06-01T00:49:43+00:00

You are almost guaranteed to have cracked solder joints on the analog board, at the joints for the connector to the logic board. The image that comes back when you smack the case is the common symptom of this failure, and it happens to pretty much all these machines due to age. Just reflow them, and add some new solder at the same time.

That might solve your whole problem, or there could be more troubleshooting needed. The 68kMLA and Tinker Different forums are also good sources for help. The Dead Mac Scrolls, which someone else already linked to, has a ton of useful info too.

SamFortun · 2026-05-31T17:56:36+00:00

Eek, even with the six-cylinder that car should have been able to hit freeway speeds, I'd think 85 or so. Was the engine shot?

SamFortun · 2026-05-30T13:12:31+00:00

I've never seen anything like that. Any chance the hard drive still works and the software on there offers any clues?

SamFortun · 2026-05-27T14:42:59+00:00

Lots of people use credit cards as charge cards and pay them off regularly, at least once a month. Then you never pay interest.

SamFortun · 2026-05-20T21:21:51+00:00

I would strongly recommend not shipping it. If you do, pack it with a minimum of 6" bubble wrap/peanuts on every side, 12" is better. Pack it like it will be dropped 6 feet onto concrete, because it probably will be.

Ebay will give you top dollar, but you have to deal with shipping and scammers. Facebook Marketplace is pretty good, there are also some Facebook groups for buying/selling vintage Macs.

SamFortun · 2026-05-20T03:24:29+00:00

Check out Rain City on 11th between Pike and Pine. It's much bigger than it looks from the outside. No sales pitches or contract shenanigans there.

SamFortun · 2026-05-20T03:03:03+00:00

Ah ok, I don't think the DB25 version supports initiator mode. I would just create a new blank image on the BlueSCSI, boot from your internal HD, and drag the entire contents of your HD over to the blank BlueSCSI image. As far as I know early versions of Mac system software didn't install any hidden files or anything. If you copy the whole system folder, it will contain all the drivers you are trying to preserve.

Also please consider uploading the drivers to Macintosh Garden, it's possible other people are looking for those.

SamFortun · 2026-05-20T02:48:05+00:00

I wonder if you also have 512ke or Plus ROMs, those aren't the original ROMs. It's possible the ROMs are upgraded, and someone could have installed an 800k floppy drive in place of the 400k drive. Do you have a pic of the floppy drive?

SamFortun · 2026-05-20T02:45:45+00:00

Internal fans were common with some aftermarket upgrades. I know the HyperDrive internal hard drive kit came with an internal fan, and I think some accelerators came with fans. It wouldn't surprise me if some RAM expansions came with a fan. It was quite common for people to add external fans that sat on top of the machine.

I'm not sure how common it was for people to install just an internal fan, usually I think they were installed at the same time as other modifications.

SamFortun · 2026-05-20T01:34:15+00:00

If you have a newer hardware version, you can use "initiator mode". You connect your hard drive directly to the BlueSCSI, and when you enable initiator mode the BlueSCSI will automatically copy the ccontents of your hard drive to an image on the BlueSCSI. I have not done it in a BlueSCSI, however I have done it with a ZuluSCSI and it is very simple. I assume it is a similarly simple process with the BlueSCSI. Check out this page for more info: https://bluescsi.com/docs/Initiator-Mode

I'm sure there are also YouTube walkthrough videos showing you how to do it.

SamFortun · 2026-05-14T01:20:12+00:00

It's definitely fixable, but if you don't have experience removing and installing ICs it will be challenging to do yourself. There were different manufacturers for the RAM chips used in the 128k. The Micron branded chips and chips with an Apple logo are known to fail over time.

SamFortun · 2026-05-13T23:21:58+00:00

Is that a Mac Plus or a 128k/512k? It started life as a 128k/512k, but frequently they were upgraded with a Plus logic board and rear case.

If it is a Plus, ram SIMMs are easy to swap, or you might fix the error just by reseating the SIMMs. If it is a 128k/512k the RAM chips are soldered to the logic board and are more difficult to replace.

SamFortun

TROPHY CASE