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I got a keyboard recently, and it connects in the standard way, using two male PS/2 connectors, one female PS/2 connectors, and a parallel connector. You know, the usual.
So it turns out this keyboard is very weird.
it has two cables coming out of it, one of which is just a male PS/2 connector, and the other is the parallel + male/female PS/2.
it has two cables coming out of it, one of which is just a male PS/2 connector, and the other is the parallel + male/female PS/2.
And it turns out this is because this keyboard has a device in it that needs power.
So where do you get the power? From a PS/2 port!
Why is it not the one it already uses?
Shut up, that's why.
So where do you get the power? From a PS/2 port!
Why is it not the one it already uses?
Shut up, that's why.
So, it's a Key Tronic keyboard. That's nothing special, really.
And the layout is pretty standard
SURPRISE! It's a fingerprint reader.
So it's the Key Tronic F-SCAN-K001US. At least, that's what it says. The stuff that comes with it suggests that it's not really that...
It's an Identicator Technology BioLogin.
And here's the bit from the manual which explains everything about it:
August, 1998.
This was designed for Windows NT and Windows 95, neither of which had decent USB support.
August, 1998.
This was designed for Windows NT and Windows 95, neither of which had decent USB support.
The little catalog's entry on it.
They also made a mouse equivalent, which was somewhat disturbing in shape.
Looking at the bottom of the keyboard, you can see that they built this VERY MUCH on top of an existing Key Tronic keyboard.
It seems to be the back plate + mechanism of another keyboard, with a reader part jammed on the side, and a new top-mold to hold it all together.
It seems to be the back plate + mechanism of another keyboard, with a reader part jammed on the side, and a new top-mold to hold it all together.
Let's open up the scanner.
Amusingly it has a little strain-relief built into the cable, despite not needing it at all.
They clearly just used the same internals as a stand-alone fingerprint scanner
Amusingly it has a little strain-relief built into the cable, despite not needing it at all.
They clearly just used the same internals as a stand-alone fingerprint scanner
The scanner seems to be glued in. It looks like it's got some lights (one may be a photodiode?), a mirror, and a CCD camera.
Doesn't look like there's any smarts on this module.
If there are any, they'll be on the other side, I guess.
If there are any, they'll be on the other side, I guess.
Opening up the main keyboard part, it's got a metal backplate! I wouldn't have guessed that, I thought it would be cheaper than that.
And yep: it turns out the cable from the fingerprint reader doesn't interact with the main keyboard at all. They're two entirely separate modules shoved in the same shell.
The keyboard itself is rubber dome over membrane
And there's a bit of plastic on top of the rubber domes that holds onto the keys. Usually this is just integrated into the main keyboard's shell.
The main PCB is over here, and has no components on this side.
It's using one of those awful pressure-fit connectors to talk to the membrane
It's using one of those awful pressure-fit connectors to talk to the membrane
Other side is... stickery.
It's a Key Tronic PCB 63772-6, and I don't know why there's a 65105-5 sticker on top of the microcontroller
It's a Key Tronic PCB 63772-6, and I don't know why there's a 65105-5 sticker on top of the microcontroller
So the microcontroller is a Zilog part! A Z86C1505PSC
Turns out that's a Z8-based 8-bit microcontroller.
4 kilobytes of ROM, 236 entire bytes of RAM, 32 I/O lines, runs at 5mhz, can directly control 4 LEDs.
Perfect for a keyboard... Which is on purpose: it's a keyboard controller!
4 kilobytes of ROM, 236 entire bytes of RAM, 32 I/O lines, runs at 5mhz, can directly control 4 LEDs.
Perfect for a keyboard... Which is on purpose: it's a keyboard controller!
fun fact: The Z8 line started in 1979, and Zilog is still making them today.
they're much more powerful now.
Instead of 236 bytes of ram, they now have 256 bytes of ram!
Instead of 236 bytes of ram, they now have 256 bytes of ram!
Put it back together and it still works.
I know because I'm typing on it now!
It's a bit mushy (as you'd expect from a rubber-dome-membrane keyboard) but not too bad.
I know because I'm typing on it now!
It's a bit mushy (as you'd expect from a rubber-dome-membrane keyboard) but not too bad.
It's got shitty rollover as you'd expect from a diodeless membrane keyboard.
You can hit 7 keys at once if you're lucky, but shift+m+y doesn't work.
You can hit 7 keys at once if you're lucky, but shift+m+y doesn't work.
>maagllv15mv515151151mccm1v11vlv155 ESI% YVEK
Sorry, my keyboard randomly switched into VERTICAL QWERTY mode. see here: https://twitter.com/Foone/status/1261467973136470019
but yeah. the fingerprint module wasn't glued in, it uses DOUBLE SIDED TAPE! that's amazing.
it also has what look like screw holes, like this is a module they were supposed to screw in and didn't for whatever reason
Unscrewed the filter on the camera: It's a little red filter. Interesting.
It screws into this bit
Under that, there's this lovely looking IC.
It has to be transparent on top because it's a CCD, but I think this is a hybrid chip, with the middle bits being CCD and the bits around the outside being logic
It has to be transparent on top because it's a CCD, but I think this is a hybrid chip, with the middle bits being CCD and the bits around the outside being logic
I should get out my microscope for this
bit closer
Here's some closer ones
Rotated 90 degrees left. I'm not sure what this array of lines is.
reposting this one because I messed up the threading
oh no, one of the LED cables detached when I was reassembling it!
I'll have to resolder that later and pull out a win95 machine and see if I can fingerprint login with it
