Handwired Apple AEK2 (M3501)

[TomahawkLabs]

I have been a big Alps fan for a while now and am finally getting around to sharing my work keeb. It's a 1990 Apple M3501 (AEK 2) that originally came with Damped Creams. These Damped Creams are the most common switches found in these keyboards. Some users may find Salmons or Damped Whites. The Damped Whites are largely identical to the Damped Creams but with a white stem.

I am using an out of production Teensy++ 2. I used this simply because it allowed for 27 usable GPIO. This allowed me to use a 6x21 matrix making this infinitely easier to wire as all the runs are largely straight shots to the next switch in the column and every row has it's own pin. Finding a microcontroller with that many GPIO is hard to come by these days. It was programed by flashing the hex created from an online firmware creation site.

I am more than happy to answer any questions regarding the handwired build. Happy Clacking!

[Rob27shred]

Very nice, I've been wanting to handwire a board just to do it really for awhile now. This gives me some inspiration for using the left over parts I have from harvesting ALPS switches or this might actually be the way I could get one of my Videowriters to work with a modern PC!

[wjrii]

Nice!  Having just rewired a 98-key with a microcontroller that only barely had enough keys (and then an 83 that still needed some contortions), tracking down an MCU with enough pins to do a clean matrix was a very good idea. 

I know it's controversial in some quarters, but would you consider retrobright on your spacebar and top case? 

Lastly, what technique did you use on the insulation on your matrix?  I find managing the insulation is the most tedious part of a handwire, trying to trim in the right places, slide it back and forth, burning it off when necessary, etc.  All very annoying.   I'm thinking of just using bare bus wire and heatshrink for my next project.

[TomahawkLabs]

Nice!  Having just rewired a 98-key with a microcontroller that only barely had enough keys (and then an 83 that still needed some contortions), tracking down an MCU with enough pins to do a clean matrix was a very good idea. 

I know it's controversial in some quarters, but would you consider retrobright on your spacebar and top case? 

Lastly, what technique did you use on the insulation on your matrix?  I find managing the insulation is the most tedious part of a handwire, trying to trim in the right places, slide it back and forth, burning it off when necessary, etc.  All very annoying.   I'm thinking of just using bare bus wire and heatshrink for my next project.

I have some Retrobrite in the closet, I just need to figure out which case out of the 4 I have is in the best condition. I think I would do the case, but for some reason I like the spacebar "road worn" so to speak.

The best tool for the job is a wire stripper like this. it grips the wire and pulls the desired length of sheathing off. Trying to grip the wire with a more traditional pliers style is possible, but would be a pin in the rear. Solid core wire is also a must. You want the wire to hold it's form so you can solder it without supporting the wire. I also used the tails of the diodes to wrap around the two leads so I had a slight mechanical hold and could more easily solder.

Bare bus wire would work great with MX style switches as the two pins are offset, but with Alps switches they are near parallel.

[wjrii]

The one I mostly use is this one, available from a dozen different brands.  It works reasonably well on solid core wire, brilliantly for it's intended purpose in fact, but it's just not very precise for this kind of work, and while it's not too bad to move short lengths of insulation up and down to the exact spot they're needed, long runs are less cooperative.  I have seen some very elegant keyboards wired with bare rod or bus wire for MX rows.  I was thinking more of using the heatshrink as diy insulation between each key (saw that somewhere on GH too, IIRC).

Full respect for a time-darkened ABS spacebar.  Enjoy!