Well, I went ahead with this project, and for the most part I would say it was a great success. I’m typing on it right now, in fact. There were a few hurdles to overcome.
First, I had to desolder all of the original switches (keeping the good ones to use as spares for other boards). This was a real pain, and I ended up ripping up the pads on the PCB in a couple of places, but luckily it was nothing that couldn’t be fixed.
I then had to add extension wires to all of the pins on the modern switches I would be using. In the end I went with Gateron browns. Not the most exiting choice, I know, but I had them on hand and I wasn’t really sure this would even work so I was reluctant to use something too expensive.
The issue is that the ALPS switches that were originally in the board are a lot taller than modern Cherry MX switches, so the pins won’t reach. Plus the ALPS pins are in different positions. So I decided to solder on short lengths of wire to allow the pins to reach the holes. Maybe there is a better way to do this, but this is my first time doing anything like this.
For the most post, these just worked after soldering them to the PCB, although I did have a couple of scary moments when it seemed like the entire board had stopped working, but apparently I had shorted something, and moving a solder joint away from a particular trace seemed to fix the problem.
Finding caps that fit this layout may actually be the biggest problem. I had to substitute a couple of keys and also a couple are the wrong profile. Amazingly the spacebar was not really an issue at all. I was able to use an Xacto knife to slightly shave down the little inserts that originally came with the board, and that let me use a 7u spacebar. Unfortunately, the original spacebar was 7.5u, so there is a bit of a space to either side, but I don’t really think it looks bad. I could theoretically alter the plate and use bigger keys to the left and right to fill the space, but that seems like a lot of work for a minor issue.
It feels really good to type on in comparison to the original switches, at least in my opinion. The pinging is also not nearly as bad. Right now I’m using it with a USB convertor to allow me to use the original Macintosh cable on a modern computer, but I think I will actually mostly be using this as a way to use a modern-feeling mechanical keyboard with a classic Mac.
I’m considering doing some aggressive retrobrighting to make the case more of a white, instead of this beige/yellow.