Repurposing a Psion MC400 keyboard
- scottc
- ☃
- Location: Remote locations in Europe
- Main keyboard: GH60-HASRO 62g Nixies, HHKB Pro1 HS, Novatouch
- Main mouse: Steelseries Rival 300
- Favorite switch: Nixdorf 'Soft Touch' MX Black
- DT Pro Member: -
Hello everyone!
As I mentioned in the "stuff you just bought" thread, I recently got a nice, but very broken Psion MC400 laptop. Fortunately, the keyboard is absolutely pristine and feels fantastic. This thread will be an interactive exhibit of a strange man trying to reverse-engineer a keyboard for the first time.
The Psion MC400 is a British-made laptop from 1989. With apparently less than 1000 units made, this is a really cool collection piece. Of course, since it was 1989, no expense was spared and the keyboard is a G80-1600 manufactured by Cherry.
The keyboard is beautiful. It looks like the original MX 60%, and even has arrow keys! The keycaps are nice, thick Cherry doubleshot, but more grey than the normal Cherry keycaps so they can't really be mixed-and-matched with them. The switches are vintage MX clears -- which, I have to say, are really quite nice. I don't even normally like MX clears very much!
Here's a shot of it alongside my blue Alps Alps64 board:
It's basically an ISO HHKB with arrow keys, guys! How cool is that?!
Since the laptop itself is probably beyond my repair skills, I've decided to repurpose the keyboard.
Step 1: Exposing the matrix!
Thankfully, the keyboard is connected to the mainboard via an 18-pin ribbon cable. This should make accessing the matrix pretty easy, and I don't need to reverse-engineer any weird 1989 protocols.
Here's a close-up of the ribbon:
The ribbon is connected to the keyboard's PCB via a ribbon connector, meaning that this ribbon should hopefully be pretty easy to replace with something that gives me access to the pins for reverse-engineering the matrix (wow, that last part sounds really cool without context).
This cable looks like a good fit, but I have yet to check pitch etc:
http://www.aliexpress.com/item/39240900 ... 4495b56aa0
More info as I have time to do it!
As I mentioned in the "stuff you just bought" thread, I recently got a nice, but very broken Psion MC400 laptop. Fortunately, the keyboard is absolutely pristine and feels fantastic. This thread will be an interactive exhibit of a strange man trying to reverse-engineer a keyboard for the first time.
The Psion MC400 is a British-made laptop from 1989. With apparently less than 1000 units made, this is a really cool collection piece. Of course, since it was 1989, no expense was spared and the keyboard is a G80-1600 manufactured by Cherry.
The keyboard is beautiful. It looks like the original MX 60%, and even has arrow keys! The keycaps are nice, thick Cherry doubleshot, but more grey than the normal Cherry keycaps so they can't really be mixed-and-matched with them. The switches are vintage MX clears -- which, I have to say, are really quite nice. I don't even normally like MX clears very much!
Here's a shot of it alongside my blue Alps Alps64 board:
It's basically an ISO HHKB with arrow keys, guys! How cool is that?!
Since the laptop itself is probably beyond my repair skills, I've decided to repurpose the keyboard.
Step 1: Exposing the matrix!
Thankfully, the keyboard is connected to the mainboard via an 18-pin ribbon cable. This should make accessing the matrix pretty easy, and I don't need to reverse-engineer any weird 1989 protocols.
Here's a close-up of the ribbon:
The ribbon is connected to the keyboard's PCB via a ribbon connector, meaning that this ribbon should hopefully be pretty easy to replace with something that gives me access to the pins for reverse-engineering the matrix (wow, that last part sounds really cool without context).
This cable looks like a good fit, but I have yet to check pitch etc:
http://www.aliexpress.com/item/39240900 ... 4495b56aa0
More info as I have time to do it!
- Stabilized
- Location: Edinburgh
- DT Pro Member: -
Are you planning to design a case for it if you get it working?
- scottc
- ☃
- Location: Remote locations in Europe
- Main keyboard: GH60-HASRO 62g Nixies, HHKB Pro1 HS, Novatouch
- Main mouse: Steelseries Rival 300
- Favorite switch: Nixdorf 'Soft Touch' MX Black
- DT Pro Member: -
I'm going to design a new case. It won't fit in a normal 60% case, the PCB is too big! I'd rather not modify the original PCB and I have no idea how I'd route the ribbon cable from the front of the PCB and still fit it in a case.
Plus, I want a nice HHKB-style case covering the places without switches!
Plus, I want a nice HHKB-style case covering the places without switches!
- HzFaq
- Location: Windsor, UK
- Main keyboard: Phantom
- Main mouse: CST L-Trac
- Favorite switch: MX Clears
- DT Pro Member: -
Nice work, looking forward to seeing how this turns out.
I was thinking of doing something similar but the up arrow/right shift position drove me up the wall (plus, my unit works and I didn't really want to kill it) so decided to keep the unit whole and just use the caps on my GH60.
edit - Actually, looking at it I think that's the FaceU I sold...
What sort of condition is the rest of the case in? Mine has a chunk out of it, if you're willing to let it go I might try and use it to repair mine .
I was thinking of doing something similar but the up arrow/right shift position drove me up the wall (plus, my unit works and I didn't really want to kill it) so decided to keep the unit whole and just use the caps on my GH60.
edit - Actually, looking at it I think that's the FaceU I sold...
What sort of condition is the rest of the case in? Mine has a chunk out of it, if you're willing to let it go I might try and use it to repair mine .
- scottc
- ☃
- Location: Remote locations in Europe
- Main keyboard: GH60-HASRO 62g Nixies, HHKB Pro1 HS, Novatouch
- Main mouse: Steelseries Rival 300
- Favorite switch: Nixdorf 'Soft Touch' MX Black
- DT Pro Member: -
That looks so nice! If all else fails, I'll just do what you did. I'm keen to give the arrows a go, I think they look really cool where they are, especially with the up arrow bump... we'll have to see how usable it is though.
- scottc
- ☃
- Location: Remote locations in Europe
- Main keyboard: GH60-HASRO 62g Nixies, HHKB Pro1 HS, Novatouch
- Main mouse: Steelseries Rival 300
- Favorite switch: Nixdorf 'Soft Touch' MX Black
- DT Pro Member: -
Anyone have any idea about the connector?
I completely missed your comment about the case, Hz. If I can't get the laptop working I'll gladly give you whatever parts you need.
I completely missed your comment about the case, Hz. If I can't get the laptop working I'll gladly give you whatever parts you need.
- zedstarr
- Location: NWest England
- Main keyboard: Keychron K6
- Contact:
just managed to get a USB-MC400 keyboard working thanks to Frank Adams' Teensyduino sketch - the MC400 keyboard matrix is unique in that the On/Esc key has 2 dedicated lines (i.e. not shared with any other keys) to ASIC2 which is the custom chip that handles power on/off for the MC. Of the 18 pins in the connector it's a 9x9 matrix but with 2 pins dedicated to On/Esc it's 8x8 for the other 60 keys. This confused Marcel's python so I had to hack it around considerably to get it working!
video of USB-MC400 keyboard in action!
(Apologies, slow one-handed typing whilst holding the phone in the other hand )
. .
My Teensy LC sketch is here.
.
Full keyboard matrix, including the case-mounted supplementary buttons (Task/Del/Home/End/PgUp/PgDn/LCD/Rec):
video of USB-MC400 keyboard in action!
(Apologies, slow one-handed typing whilst holding the phone in the other hand )
. .
My Teensy LC sketch is here.
.
Full keyboard matrix, including the case-mounted supplementary buttons (Task/Del/Home/End/PgUp/PgDn/LCD/Rec):