1994 Hi Tek 725 / Space Invaders RT 101+Intel Keyboard

hellothere · 16 Nov 2020, 20:47

Really, I wasn't going to do this as a Workshop project. Unfortunately, when I removed some of the switches, I found out that the top of the switch plate had rust, so I had to desolder all the switches to get the plate off.

Spoiler:

All that white is rust. Forgot to mention that the keyboard is PS/2.

The 'board has linear grey switches with a somewhat heavier neon "green" switch for the spacebar.

Spoiler:

The stuff that looks like keyboard chow is rust.

One of the things I found interesting was that the wire stabilizers, except for the ones on the Enter key, are part of the switch itself and the switch has a different housing.

Spoiler:

Left, with the different housing. Right, without.

The switches have four pins and locking tabs. It took me a couple bits of trial and error to figure out how to deal with the tabs.

Spoiler:

The solution: after you've desoldered the pins, push up on the pins with your thumb. You don't need to use a lot of force. Use the pointy part of a plastic spudger to push in a tab in toward the slider (so, left to right or right to left). When it pops, push in the other tab. You can CAREFULLY pull the switch out by its slider. Easy peasy.

I've already ultrasoniced the key caps and retr0brighted the case, which brings me to one other problem: the lock lights sticker was really just a sticker. That and the back sticker that said the part number, etc. wore away into scrap. I picked up a new Model M sticker and it fits almost perfectly.

The final "usability" problem is that one of the stabilizer mounts for the Enter key just wasn't there. Check out my WTB. If you have one, please contact me.

I'm weighing the idea of lubing the switches. I do have a few extras for if I screw up. It's extremely easy to remove the slider. It's difficult to get it back on without damaging the contacts.

The final thing is that the keyboard was missing the screw for the ground, which is about middle left on the keyboard. Surprisingly, the 'board still did work before I found out about that. I'm going to have to search my bucket o' screws to see if I have a screw and nut that are the right size.

More stuff as I go along. As always, if anyone wants to add my pics to the wiki, please go ahead.