The Plus Project: Part 1

Restoring the Macintosh Plus to working order!
Classic Mac Repair Notes

Finding the Plus

So I’ve had this old broken Macintosh Plus collecting dust underneath my bed for a couple years now. I’ve always wanted to work on it, but never really had the time. Something always came up for one reason or another. Anyway, the days are longer and it’s almost too hot to step outside. Figured I had some time to kill before school starts back up. By the way, this will probably be a multi-part series. I can’t fit all my research/work into one post.

Funny story. So… this Macintosh Plus isn’t actually mine. I first came across it at a local Maker Faire during my junior year of high school. Being part of a Robotics Team, we were regularly invited to the faire in NYC to showcase the robot we had built. Overall, it usually turned out to be a fun weekend. We got free tickets, saw some amazing DIY Projects, and best of all, we got to show off our robot.

Anyway, walking around the fair, I noticed this table cluttered with vintage computers. That’s where I found the Plus. I thought it looked cool and the man responsible said all the stuff on the table was free in hopes that someone would get a use out of them. I told him I would try to get the Plus to boot up again. He said it was only missing a few components and to contact him when I got it working. I had that conversation about 5 years ago… Hopefully, it’s not too late to get in touch with him…

Inside the Vintage Computer

Now Apple first introduced the Macintosh Plus in January of 1986. Following their original Macintosh line, the Plus started with a price tag of $2599 and was largely seen as an upgrade, shipping with 1MB of RAM, a SCSI (“scuzzy”) bus, and other smaller improvements. They discontinued it in 1990, but the long production life was due to the fact that as computers got faster, Apple lowered the price and started offering the Plus as a cheaper alternative to modern units.

Using this online decoder with the Plus’s serial number (F629063M0001A) I found at the bottom, this computer was the 207th manufactured one on the 29th week of 1986 (~August) in Fremont, CA. Almost 7 months after it debuted!

Opening the case was a huge hassle. For some reason, Apple opted in to using these special Torx T15 screws instead of standard flatheads. Even then, most standard T15 screwdrivers wouldn’t have worked because to access the deeply recessed screws in the case, the screwdriver also had to be long and thin in diameter. Several hardware stores and bike shops later, I had given up and decided to just buy it from Amazon.

With the case open and the CRT monitor discharged, the first thing I did was take a picture of Steve Jobs’ signature. According to a blog post by Andy Hertzfeld, in the early days of Apple, Steve Jobs encouraged the design team to consider themselves as artists building the Macintosh; and with any artist, it was only appropriate for them to sign their work which eventually got engraved into the final plastic molding of the case.

Looking inside, the computer seemed mostly intact. Despite some rust/corrosion near the PRAM battery slot, dust, and spider webs(?), the Plus was in fairly good shape.

From here, I decided to disassemble the entire unit so I could get rid the dust that had collected over the years. I read somewhere online that soaking the entire board in soapy water and then giving it time to properly dry worked well, and in some cases, even helped fix computer glitches. I ended up soaking the power supply, internal metal casing, and logic board (making sure to take out any removable IC’s/wires). The floppy drive was cleaned using a can of compressed air and I ended up wiping down the CRT monitor and case with a wet paper towel.

The Components

Feel free to skip over this section. This part is mostly for me to fanboy over some of the older chipsets. Some of the components are labeled in the picture.

The Logic Board
The Power Supply
CRT Monitor
The Floppy Drive

Decisions, Decisions

Moving forward, I essentially had 3 options of what I could do for this project. Restoring the Plus to its original condition, upgrading it with new parts, or selling it as is.

The Plus had been in my possession for several years now and if I wanted to sell it, I would have. Looking on eBay, the maximum price for a broken Plus price revolved around < $100 so it didn’t make sense to sell.

Restoring it seemed like an obvious choice at first until I started looking into the cost of repair. Assuming all the existing components worked properly, I was still looking at $200 in repair costs. This included buying a keyboard and mouse compatible with the Plus, finding a working SCSI HD since the Plus had no permanent storage, and getting a copy of the original operating system on a double density floppy disk. The Plus’s floppy drive reads only double density disks which are grossly outdated and obsolete. If an issue did come up, however, with the logic/power board, that price could range anywhere from $300 to $400. It just didn’t make sense, in the end, to spend all that money working on something that could only run the Macintosh OS.

I finally arrived at my last choice, upgrading it with new parts. Looking online, I ended up finding several projects that focused on dumping the decade-old electronics of the Plus for a Raspberry PI or other SCB, but keeping the original case and running the system with an emulator. Overall, this seemed like a good idea to me. I would still be able to keep the look of the old system while turning it into a modern computer. I ended up deciding on upgrading the Plus.

The Project (so far)

That’s pretty much it for now. I’ll add new posts as I go about working on this project. So excited to see how it ends up turning out!