Loudest EVER Model F XT Proof of Concept with Xwhatsit Controller

[orihalcon]

I've always thought it should be possible to install an Xwhatsit controller into an IBM Model F XT if the original controller was cut off and directly wired to the existing traces. This is the proof of concept and it works great! To make the video more interesting, I hooked up an old solenoid driven bell from an IBM typewriter that I had laying around. Makes for the loudest USB powered keyboard I've ever experienced!

Story behind this one is that I came across some Model F XT's that had some sort of third-party-modification to the original controllers and they do not work with modern converters because of this. It was either junk the PCB or test out my old theory. Basically just cut the original controller off with a Dremel. Upside down mounting of the Xwhatsit made more sense since this was the orientation of the traces and it happens to divert the USB cable in the direction where there is more free space in the case anyway. The assembly does fit in the case just fine as pictured without any issues, just couldn't fit the bell in there!

Close up of Xwhatsit for wiring purposes should you want to try this at home:

IMG_3089.JPG (2.94 MiB) Viewed 6600 times

[PlacaFromHell]

Amazing! How did you performed such a clean cut over the areas with the copper mask?

[xxhellfirexx]

How does it sound when you hold a key or a bunch of keys down? Does it sound like an old phone?

[depletedvespene]

The assembly does fit in the case just fine as pictured without any issues, just couldn't fit the bell in there!

GET. A SMALLER. BELL. NOW!

I absolutely love this. Would the pictured bell fit on an F122, though?

[green-squid]

Now imagine using a big School bell!
That would have to run on 120V though

[tigpha]

Hilarious! Love it. Just the thing to use in a open plan office full of folks on the phone Revenge!

[zrrion]

This is something I've wanted to try myself. It turned out incredible BTW!

[digital_matthew]

I'd love a separate bell solenoid to go off whenever I hit the Enter key, like an old-school typewriter.

[depletedvespene]

I'd love a separate bell solenoid to go off whenever I hit the Enter key, like an old-school typewriter.

How... how did I not think of this before? Matthew, this is BRILLIANT.

[orihalcon]

Amazing! How did you performed such a clean cut over the areas with the copper mask?

Just used a Dremel with a cutting wheel attachment actually. I think you could probably also use a bench grinder, but grinding the entire controller off would probably make a lot more potentially harmful dust

[rhaberkorn]

Wouldn't it be possible to simply desolder two ICs from the original PCB and attach the wires via their former pins? (Perhaps you'll need to kill a few more ICs to make sure the old controller is electronically dead.)

I've also got a faulty XT. It's not completely dead but sometimes produces ghostly keypresses. (Needless to say, I excluded all possible converter faults.)
If I won't succeed in repairing the original electronics, I will consider building a TH-xwhatsit on a custom prototyping-PCB with pin headers at the exact positions of the original controller's ICs. This board could then either be soldered to the original controller or plugged into it using male-female pin headers, ensuring easy maintenance.