Keyboard foam discs (WAS: Re: Advice on Lisa 2 restoration)

--- On Sun, 4/3/11, Mike Loewen <mloewen at cpumagic.scol.pa.us> wrote: I used a roll of foam rubber weatherstripping from the hardware store - I found one that was the correct thickness, I'll have to look for the brand name and part number. For the conductive side, I used a cut-up antistatic bag, and for the plastic side, I used some thin flexible plastic I found somewhere - but I'm sure a transparency film or similar would work - the stuff I had was only slightly thicker.

The foam I used was self-adhesive, so I stuck that to the plastic backing first. Then I used 3M spray adhesive to coat the top of the foam (it's only self-adhesive on one side), and glued down the anti-static bag. After that, let it dry thoroughly (otherwise, the glue sticks the foam together and holds it compressed). Once dry, I punched out lots of little foam discs and populated the keyboard. Tedious, but not too bad. I had better results punching if I punched from the mylar side than from the plastic side - but it could have just been my punch/material combination. It takes a couple hours, but it's worth it to have a functional keyboard. Again, the foam I used was slightly stiffer than the original stuff, but it worked great. The keyboard I rebuilt in this manner was for a Franklin Ace 1000, but I've tested the discs in other keyboards and they work fine. The Keytronic mechanism seems to be the same across the various keyboards.