Dolch keyboard adapter RJ11-type to PS/2 or USB?

[Hypersphere]

I have acquired a Dolch PAC 64 keyboard that has a RJ11-type connector to the Dolch computer. I know that there  have been previous posts on GH about how to make an adapter to convert the cable to PS/2. However, I thought I would reopen the issue to see if there have been any new developments. Are there off-the-shelf adapters for this type of connector to convert it to PS/2 or even directly to USB, so that the Dolch keyboard could be used with a modern computer? My understanding is that the keyboard "speaks" the PS/2 protocol, and the RJ11-type connector pins are GND, +5V, Kb data, and Kb clock. If possible, I would like to avoid soldering on the keyboard PCB, in part so that I could keep the original connector for use with Dolch computer and to simplify making a connection with a contemporary computer. Thanks for suggestions that you might have.

[rootwyrm]

I have acquired a Dolch PAC 64 keyboard that has a RJ11-type connector to the Dolch computer. I know that there  have been previous posts on GH about how to make an adapter to convert the cable to PS/2. However, I thought I would reopen the issue to see if there have been any new developments. Are there off-the-shelf adapters for this type of connector to convert it to PS/2 or even directly to USB, so that the Dolch keyboard could be used with a modern computer? My understanding is that the keyboard "speaks" the PS/2 protocol, and the RJ11-type connector pins are GND, +5V, Kb data, and Kb clock. If possible, I would like to avoid soldering on the keyboard PCB, in part so that I could keep the original connector for use with Dolch computer and to simplify making a connection with a contemporary computer. Thanks for suggestions that you might have.

Yes, it does wire adapt to PS/2 for the PAC64 and later models. All you need is an RJ11 socket and a male PS/2 and some wire. Somebody else should be along shortly with the pin-out I'm sure - I can't find it at the moment.

[Hypersphere]

I have acquired a Dolch PAC 64 keyboard that has a RJ11-type connector to the Dolch computer. I know that there  have been previous posts on GH about how to make an adapter to convert the cable to PS/2. However, I thought I would reopen the issue to see if there have been any new developments. Are there off-the-shelf adapters for this type of connector to convert it to PS/2 or even directly to USB, so that the Dolch keyboard could be used with a modern computer? My understanding is that the keyboard "speaks" the PS/2 protocol, and the RJ11-type connector pins are GND, +5V, Kb data, and Kb clock. If possible, I would like to avoid soldering on the keyboard PCB, in part so that I could keep the original connector for use with Dolch computer and to simplify making a connection with a contemporary computer. Thanks for suggestions that you might have.

Yes, it does wire adapt to PS/2 for the PAC64 and later models. All you need is an RJ11 socket and a male PS/2 and some wire. Somebody else should be along shortly with the pin-out I'm sure - I can't find it at the moment.

Thanks -- good to know this. Eager to give it a try. I recall seeing pin-outs on GH and Deskthority; I will search for them. In the meantime, if anyone else has any tips, I look forward to seeing these as well.

[Soarer]

Pinout, for 6P6C (RJ11) or 8P6C. I think the comment about the 4P4C (RJ9/RJ10/RJ22?) being the same as the middle 4 pins of the 6P6C is correct, but I haven't verified it.

Which one have you got? 6P6C or 4P4C?

If it's 6P6C, then an ADSL adapter might be a nice way to build it - could probably fit a Teensy in there to go to USB. Or find a telephone extension cable and replace its plug with a PS/2 connector.

If it's 4P4C, that's the same as a telephone handset, and extension cables aren't common - search for that and you get cables with plugs on both ends! Searching for RJ22 female (or RJ10 female, or RJ9 female) seems to find things that might be useful.

(nPmC simply means n positions, m connections).

[Hypersphere]

Thanks, Soarer! This looks like very helpful information. I don't have the Dolch yet; expecting delivery next week.

[Hypersphere]

Oops! I just opened the pinout diagram. This is a PAC65 with 6 wires. The Dolch I have ordered is a PAC64 with 4 wires. However, the principle is the same and the 4 wires should correspond to Clock, Data, +5V, and Ground. Thanks.

[Soarer]

I've got a 4p one... I'll check later.

[Tarzan]

I just opened the Dolch Pac64 keyboard case I acquired, and I think it uses an actual phone cable connector.  The connecting cable RJ11 out to the PAC unit, and inside the keyboard it terminates in a little RJ9, female jack right zip-tied to a daughter board in the case.  I guess this way a field tech could easily replace the cable if it got damaged.



I've got a RJxx crimping tool, so I'm going to try making a PS2 to RJ9 cable, to keep it as stock as possible.  I'll post pics once I get it put together and tested.

[On a related note; is there actually a screw under the Dolch logo itself?  What a complete PITA!]
 

[Tarzan]

No joy with the Dolch keyboard. 

I've tried every combination of wires from the RJ9 to a PS2 cable, even tried the PS2/USB adapters from the GeekHack store, but the keyboard remains non-functional.  I get a flash from the indicator LEDs when I plug it in or reboot (using either the keyboard or the mouse PS2 ports), but that's the extent of it.

Tested connectivity through the modded cable using a multimeter, and I seem to have all the right connections going to the matching PS2 pins, perhaps the board itself is shorted somewhere... 

[Hypersphere]

If you have the Dolch computer, does it boot, and does the keyboard work with the Dolch computer?

[Tarzan]

If you have the Dolch computer, does it boot, and does the keyboard work with the Dolch computer?

Excellent suggestion!  Let me give that a try....

[Tarzan]

If you have the Dolch computer, does it boot, and does the keyboard work with the Dolch computer?

Excellent suggestion!  Let me give that a try....

Huh.  The Pac boots, and does work with the stock keyboard cable. 

So that means somethings wrong with my wiring...  Crap.

Back to the test bench.   

[Hypersphere]

The good news is that the keyboard and Dolch computer haven't been fried.

[Tarzan]

The good news is that the keyboard and Dolch computer haven't been fried.

That's true.  It sure brings me back to see "Processor: Pentium-S" and the memory test upon boot.   

I'm sure I've got my wires crossed somewhere.

[Tarzan]

Got it to work, finally.  Issue turned out to be the length of the PS2 cable I was attempting to use.  Must have been too long for the voltage to register properly, cutting it down to a more reasonable 6' and it works just fine.

Just a hasty soldering job at the moment, going to do a more permanent fix once I get a new PS2 cable.

Huge relief, thought I'd terminally borked something.  Thanks for the tip to check the stock cable with the PAC!

[Hypersphere]

Glad it worked! When you've finished, could you please do a post that clearly shows the wiring you used? I have a Dolch and would like to do the same thing when I can find the time. Thanks.

[Tarzan]

Glad it worked! When you've finished, could you please do a post that clearly shows the wiring you used? I have a Dolch and would like to do the same thing when I can find the time. Thanks.

I will do that! 

[Tarzan]

Following up on my earlier post, further adventures in Dolch cabling.

I found the crimp tool I remembered having, but it was only for RJ45 connectors, not the tiny RJ9 ones I needed.  Being an impatient sort, I decided to go ahead and solder on the new cable I got from Nubbinator, instead of waiting for the right adapter (sound familiar?)

At first I tried soldering on the recycled RJ9 telephone handset connector I'd used to test the board, but I think the stranded wire was just too friable, I ended up breaking it when I tried to strip it for soldering.  So I took apart the female RJ9 connector inside the case and used that to solder on the new longer PS2 cable.

The Dolch pinout linked earlier in the thread refers to a six-pin connector, but indicates the middle four wires map to the RJ9, so I started there.
 

Going by the Dolch pinout linked above, and a PS2 keyboard pinout (http://pinouts.ru/Inputs/KeyboardPC6_pinout.shtml), I identified which wires in the PS2 cable needed to be soldered to the RJ9 wires.


Wires from the Dolch PCB (Left to Right in image):
Black = Ground
Green = +5v
White = Data
Red = Clock


I soldered on the longer PS2 cable (ignore the crappy tape job, please!), and stripped back a couple of inches of the covering to make a thinner cable, as I didn't want to cut up the Dolch case. 

Tested okay, using one of the new GeekHack store PS2-to-USB adapters, so I buttoned up the case.  All of the case screws are under the rubber feet, and two of the feet were already missing, so I used some spare furniture bumpers to cover the screws.



Short list of things to do the next time:
1. New case screws.  The Phillips heads of the stock screws were filled with crusty rubber cement, and aren't in very good shape after a couple of rounds of taking off and replacing.
2. Replacement rubber feet pads.  The ones I had on hand are decent, but I'd like to find some smaller diameter pads that will fit the stock case divots.
3. Heatshrink the PS2 cable. Tape works, but it looks half-assed.

[HotKillerZzz]

Hi I still do not get it. I have a solder, a ps2 to usb cable and the dolch 64. What do I do? How to solder the original cable to the ps2? Could anyone give me a video? Thanks.

[HotKillerZzz]

And when I cut the wire in the ps2 to usb converter, there are only 4 wires.

[Tarzan]

And when I cut the wire in the ps2 to usb converter, there are only 4 wires.

Those are the only four wires you will need, even though the connector has more pins...  I modded a PS2 cable to fit the case, then I used an adapter to convert PS2 to USB. 

Do you have both an adapter and a cable?  You don't need to cut the wire off the adapter (although I guess you could to make a longer USB cable).

[HotKillerZzz]

I have got this.

[HotKillerZzz]

So what do I do?which color go to which color? I still dun get all these pins on the ps2 thingy.

[Soarer]

NEVER trust the wire colours to be anything logical!

Have you got a multimeter? Alternatively, an LED and (appropriate) resistor would let you work out which is 0V and +5V (on the adapter), and after that trial and error is OK for working out which is clock and which is data.

[digi]

NEVER trust the wire colours to be anything logical!
Have you got a multimeter? Alternatively, an LED and (appropriate) resistor would let you work out which is 0V and +5V (on the adapter), and after that trial and error is OK for working out which is clock and which is data.

This ^. What I did to make mine, just look up a diagram of a ps/2 male connector and use a multimeter to find your wires. Then crimp a 4P4C connector on the end and use a phone splitter to connect them it up (it has 4 connections opposed to 2 on a rj11 coupler). You can hide the phone splitter behind your monitor or whatever.

[dorkvader]

I plan to just cut the end off one of those ID innovations multimode usb adapters and crimping it to a jack to plug into the keyboard directly. It's the perfect length, and will work splendidly with a usb extension cable.

[HotKillerZzz]

problem is i dont have a crimper. Only got a solder and those kind of stuff. what steps should i take?