Adapting P70 Keyboard to PS/2
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- Location: United States
- Main keyboard: AEK II Mitsumi (rotating)
- Main mouse: G203
- Favorite switch: Orange Alps
- DT Pro Member: -
Hello.
Recently I came across a P70 keyboard which I hoped to easily convert to PS/2. However, it turns out to not be as easy as is reported by every single post on here.
I spliced up a Fellowes Keypad, which had wires of orange, red, brown, and black color. My friend tested for continuity, and two led to pins reported as "n/c" or not connected. We assumed that the pins were for split PS/2, and coded the orange as data and the brown as clock.
Orange matched up to pin 2 on the ps/2 pinout. Brown matched up to pin 6.
We used jumpers to match as follows:
Fellowes Keypad - P70
Orange ("Data") - Red
Brown ("Clock") - Green
Red ("VCC") - Yellow
Black *"GND") - Black
However nothing happened when we plugged it in. No light or any response from the keyboard whatsoever.
Any help would be appreciated.
Here is the photo I used to attempt the first wiring:
Recently I came across a P70 keyboard which I hoped to easily convert to PS/2. However, it turns out to not be as easy as is reported by every single post on here.
I spliced up a Fellowes Keypad, which had wires of orange, red, brown, and black color. My friend tested for continuity, and two led to pins reported as "n/c" or not connected. We assumed that the pins were for split PS/2, and coded the orange as data and the brown as clock.
Orange matched up to pin 2 on the ps/2 pinout. Brown matched up to pin 6.
We used jumpers to match as follows:
Fellowes Keypad - P70
Orange ("Data") - Red
Brown ("Clock") - Green
Red ("VCC") - Yellow
Black *"GND") - Black
However nothing happened when we plugged it in. No light or any response from the keyboard whatsoever.
Any help would be appreciated.
Here is the photo I used to attempt the first wiring:
Last edited by consideringquiet on 18 May 2019, 22:23, edited 2 times in total.
- snacksthecat
- ✶✶✶✶
- Location: USA
- Main keyboard: SSK
- Main mouse: BenQ ZOWIE EC1-A
- DT Pro Member: 0205
- Contact:
The first thing to check would be is it getting (enough) power?
Do you have a multimeter?
Open up the keyboard and look for all of the ICs (chips).
Use your multimeter to measure the voltage by touching the probes to the pins indicated in the picture.
Each one should measure close to 5v (probably like 4.6-4.8 in reality).
Note: these aren't always the Vcc and Gnd pins, just very frequently. If you google the number written on each chip, you can usually find the datasheet which will tell you the exact pinout of the chip.
Do you have a multimeter?
Open up the keyboard and look for all of the ICs (chips).
Use your multimeter to measure the voltage by touching the probes to the pins indicated in the picture.
Each one should measure close to 5v (probably like 4.6-4.8 in reality).
Note: these aren't always the Vcc and Gnd pins, just very frequently. If you google the number written on each chip, you can usually find the datasheet which will tell you the exact pinout of the chip.
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- Location: United States
- Main keyboard: AEK II Mitsumi (rotating)
- Main mouse: G203
- Favorite switch: Orange Alps
- DT Pro Member: -
I'm not certain it's possible for me to disassemble it, just due to the sheer number of clips the keyboard uses to stay together. I do not wish to damage the board further than I already have.snacksthecat wrote: ↑18 May 2019, 22:12The first thing to check would be is it getting (enough) power?
Do you have a multimeter?
Open up the keyboard and look for all of the ICs (chips).
Use your multimeter to measure the voltage by touching the probes to the pins indicated in the picture.
Each one should measure close to 5v (probably like 4.6-4.8 in reality).
Note: these aren't always the Vcc and Gnd pins, just very frequently. If you google the number written on each chip, you can usually find the datasheet which will tell you the exact pinout of the chip.
Is there any other way I can attempt to solve this externally? I fear I may have permanently damaged the board through attempting to test it.
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- Location: United States
- Main keyboard: AEK II Mitsumi (rotating)
- Main mouse: G203
- Favorite switch: Orange Alps
- DT Pro Member: -
Also, I saw a comment online instructing not to join the two shield grounds. Is there any reasoning for this?
- snacksthecat
- ✶✶✶✶
- Location: USA
- Main keyboard: SSK
- Main mouse: BenQ ZOWIE EC1-A
- DT Pro Member: 0205
- Contact:
Can you post the ps2 pinout picture you referred to in the OP?
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- Location: United States
- Main keyboard: AEK II Mitsumi (rotating)
- Main mouse: G203
- Favorite switch: Orange Alps
- DT Pro Member: -
Sure:snacksthecat wrote: ↑18 May 2019, 22:21Can you post the ps2 pinout picture you referred to in the OP?
- snacksthecat
- ✶✶✶✶
- Location: USA
- Main keyboard: SSK
- Main mouse: BenQ ZOWIE EC1-A
- DT Pro Member: 0205
- Contact:
You confirmed with the continuity tester that each of the colors from the keypad cord correspond with those positions in your ps2 pinout image?
I'll keep thinking but nothing is jumping out at me immediately. Do you have a teensy? Soarer's simple logic analyzer would be a good tool to test with if you do have a teensy or promicro board laying around.
I'll keep thinking but nothing is jumping out at me immediately. Do you have a teensy? Soarer's simple logic analyzer would be a good tool to test with if you do have a teensy or promicro board laying around.
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- Location: United States
- Main keyboard: AEK II Mitsumi (rotating)
- Main mouse: G203
- Favorite switch: Orange Alps
- DT Pro Member: -
I did, however, two cables led to pins that are supposedly not supposed to be connected as per the image.snacksthecat wrote: ↑18 May 2019, 22:29You confirmed with the continuity tester that each of the colors from the keypad cord correspond with those positions in your ps2 pinout image?
I'll keep thinking but nothing is jumping out at me immediately. Do you have a teensy? Soarer's simple logic analyzer would be a good tool to test with if you do have a teensy or promicro board laying around.
I do have a teensy, but its not really usable right now. Still sitting in my failed NCR 4950 project. I can't seem to catch a break here.
-
- Location: United States
- Main keyboard: AEK II Mitsumi (rotating)
- Main mouse: G203
- Favorite switch: Orange Alps
- DT Pro Member: -
-
- Location: United States
- Main keyboard: AEK II Mitsumi (rotating)
- Main mouse: G203
- Favorite switch: Orange Alps
- DT Pro Member: -
Has anyone done this conversion before?
- Chyros
- Location: The Netherlands
- Main keyboard: whatever I'm reviewing next :p
- Main mouse: a cheap Logitech
- Favorite switch: Alps SKCM Blue
- DT Pro Member: -
I literally just connected the wires from the PS/2 cable to those from the P70's; twisted them together and then joined by soldering. I can't remember the details anymore unfortunately; it's been a while. If you want I can unscrew my converter box and look inside at what I did .