Archiving old floppy disks with the Greaseweasel

Posted on by

My Christmas wish list was very short this year, and a bit nerdy. (well ok… really nerdy) One of the things I had on my list was an oddly named open source bit of hardware called a Greaseweazel. This tiny little circuit board is a powerful tool that makes it possible

Greaseweazel circuit board
Greaseweazel v4.1

…to archive just about any type of floppy disk on a PC. You can build it yourself as a DiY kit, or order one pre-assembled. (I’d recommend ordering it pre-built unless you have a hot air rework station and are good with SMD soldering) When complete, the board connects to your computer via USB-C and to a floppy drive via a standard PC floppy ribbon cable. (you’ll also need a standalone power brick with a molex output, or a spare PC power supply for the floppy drive itself)

What makes the Greaseweazel so powerful is that it doesn’t really care about the format of the disk as it just reads the raw magnetic flux transitions straight from the read heads on the drive. (basically the raw analog signals recorded on the magnetic media itself) This can make it possible to extract data from disks that would otherwise be completely unusable. It also gives you the potential to make copies of damaged disks and potentially repair them at a later time digitally.

In addition to the native Greaseweazle software, there are several other open source toolkits that support the hardware and make working with certain types of disks easier. I’ve mostly been using FluxEngine and a windows tool called FluxMyFluffyFloppy which gives the native software a graphical interface. Another useful tool is HxC Floppy Emulator. (if you’ve ever seen tech youtubers working with graphical representations of floppy images, you’ve probably seen this)

My initial setup with a 1.2M high density 5.25in drive

One of the first priorities I had for the Greaseweazle was backing up some of the quickly deteriorating Apple II disks in my collection. Many of them were too far gone to bring back, but I’m hopeful that some of the flux images I made can be reconstructed. I also 3D printed a case for the device to give it a little

…protection and make it easier to handle. I also tried working with some 3.5in Apple Macintosh floppies, in both 800k and 1.44M varieties, but found this to be trickier than the older Apple II format. Unfortunately I also discovered some of these disks were also starting to deteriorate. Now that I’ve restored the Macintosh IIfx, I may just use it to make some disk images.

Visual Floppy Render
using HxC to visualize the data captured in a flux image

Macintosh IIfx – history & restoration

Posted on by

Restoring the Macintosh IIfx actually started with a desire to run A/UX on the machine. When I found out just how badly degraded my IIfx had become, I set out to preserve it… hopefully for a long time to come.

Macintosh II reference image from Wikipedia

The Macintosh II was released to the public in March of 1987. It was based on a Motorolla 68020 CPU running at 16Mhz paired with a 68881 math co-processor. This beast of a machine (by 1980’s standards) was a departure from the original monochrome Macintosh line resembling something more like the PCs and workstations of the era.

Like those machines, the Mac II was expandable with add-in cards and required both a display card and separate monitor. Apple would update the design twice, first with the Macintosh IIx which upgraded the CPU and co-processor to the 68030/68882 respectively, and lastly the Macintosh IIfx. The Macintosh IIfx was released 2 years after the IIx in 1990 and was Apple’s attempt to see just how much performance they could squeeze out of the Motorolla 68030-based Macintosh IIx platform.

The Macintosh IIfx was still based on the 68030, but ran at over twice the speed of the IIx clocking in at 40Mhz. Apple didn’t stop there though. 72-pin SIMMs weren’t quite ready in time, so Apple crafted bespoke 64-pin SIMMs that were essentially DIMMs in the shape of a 32-pin SIMM module. This gave the Mac IIfx much faster memory speeds than could be achieved with standard memory of the time, but they didn’t stop there either. The Mac IIfx supported anywhere from 4MB to 128MB of RAM, an eye-watering amount in those days. The downside was it had a price to match these specs, coming with a base price of $9k up to $12k depending on the configuration. (that’s in 1990 dollars… what would cost roughly between $22k and $29k in today’s money) That’s solidly in serious workstation territory, and the IIfx would be used as such for graphics work in the television and movie industry.

My example was given to me by a colleague who was cleaning out some of their things and asked if I wanted any of this old computer junk. It was a Macintosh II and I was happy to have it. What I didn’t know at the time was how special this machine was. While it had originally been sold as a Macintosh II, Apple reused the same case and power supply for the IIx and later IIfx. After the release of the IIfx, Apple offered the bare IIfx logic board as an upgrade path for Macintosh II and IIx customers. This Macintosh II was one of those machines that had been upgraded and came complete with 16MB of RAM installed, a pair of floppy drives and a couple of external SCSI hard disks. (something common with these machines at the time)

As detailed in my last post, the logic board and both floppy drives needed repair. The logic board wouldn’t even power up initially, but that was easily resolved by replacing 2 failed SMD capacitors and a little board cleaning. With that out of the way, I attempted to boot from a MacOS 7.5.0 install disk. This worked, but I noticed that not only did the auto-eject feature of the Superdrive (Apple’s name for the 1.44MB floppy) no longer function, but the drive mechanism wasn’t working entirely as it should either.

leaky 47uF 16v cap caused some minor corrosion

A later boot on the disk utility floppy revealed the older 800k floppy drive wasn’t working at all. Adrian Black covered the entire process of repairing the 800k drives in this video, so I won’t go through all the details. However, the 2 main problems are accumulated dust/lack of lubrication and a separate issue with degrading plastic gears in the eject motor assembly.

booting up after initial remediation of the logic board

Another issue that can be seen here appears to be a problem with the graphics card. There are white vertical lines at specific intervals that may indicate a fault. So far this old NEC Multisync display is the only VGA monitor I have that will work with the older macs. I’ve ordered a display output adapter that may help, but I’m not confident that it will resolve the issue.

I’ve ordered some replacement parts and have begun the process of disassembling some of the other Macs in my collection as well. All of the floppy drives, even into the PowerPC era are breaking down, likely due to the same issues. Hopefully I’ll be able to get the IIfx back up and in good working condition. To be continued…

All of the classic Macs are falling apart

Posted on by

Somehow over the years, I collected a number of Apple Macintosh machines. One I’d been meaning to get back to was a legend in it’s time, the Macintosh IIfx. This machine was a powerful workstation for the day and I was interested in seeing if it would be up to the task of running a period correct copy of A/UX. (Apple’s UNIX distribution) I pride myself on keeping all of my collection in working order, but I hadn’t used any of the classics in a couple of years and probably hadn’t touched this one in at least 4 or 5 years. I got the IIfx down from the shelf and set it up, but it wouldn’t even turn on. Strange I thought… I hadn’t used this one in a while and I’d even removed the batteries recently to keep them from leaking and damaging anything. What else could be wrong I wondered. As it turns out, quite a bit.

I knew of a range of common issues that seem to have occurred to many of these machines in the community, but mine had always worked flawlessly, so I’d assumed just taking good care of them had been enough. The Macintosh II came out in 1987 and the IIfx followed 3 years later. Mine was originally purchased as a Mac II, but has the IIfx logic board upgrade fitted. At 35yrs old, this machine is now starting to show it’s age, and as I’d find out, so are many others of this vintage and beyond. The primary issue plaguing my machine was a pair of surface mount capacitors that failed and leaked onto the logic board. This was resolved easily enough by removing them, cleaning the board and then soldering on a new set. Once it was all back together, I whipped out a set of MacOS install disks and found the next problem. While the machine did start up, the floppy drive wasn’t working quite right. The disks didn’t go in the way they were supposed to and the drives no longer even attempted to eject the disks. (one of the coolest features back in the day that made the Macs feel so special)

As it turns out, there are multiple reasons for these issues. Some are related to material science issues as the polymers used in the casing and some internal parts have destabilized and are starting to degrade. (the source of the eject issue is a plastic gear that becomes brittle and crumbles away) Others are due to electrical components that have passed their shelf life and are starting to give out. 2 of my other Macs, a Performa 550 and a PowerMac 5500/225 (both all-in-one machines) have cases that have become brittle to the point I hesitate to work on them. The Performa is severely yellowed over the entire case and is only held together with a few screws. (the mounting posts for most of them have disintegrated on the inside) The PowerMac isn’t as bad, but the floppy drive just broke and I’m hesitant to remove the front cover to extract it because it’s also in the same condition. It’s too bad really because they are interesting and unique machines that I’d really like to keep in good condition.

One good thing that’s come of all this is I’m nearly done with repairing the IIfx I initially set out to restore, but it’s also made me realize that my Mac gear and software is living on borrowed time. I’ve started disassembling several other machines and all of them are showing the same symptoms or worse. I’m also starting to archive as much of the software as I can, but some of this will have to wait until I have at least one of these Macs fully restored. (GCR encoded 800k floppies are a strange beast and archiving them on anything but a Mac is a dark art I haven’t quite mastered) These and more deserve an entry of their own, so I’ll come back and do that another time.