PC Jr. keyboard interface protocol

[misterblack]

I recently acquired an untested PC Jr, matching monitor and the "Freeboard." It's in great shape but is missing some stuff. I was missing the power supply -- so I just went ahead and ordered AkBKukU's ATX adapter for it. When I had it open, I found it had the longboard power supply and the 64k RAM expansion. I also noticed that the IR receiver is missing ... so I have no way to use the keyboard. It came with two phone cables as if those would work with the keyboard -- but not the proper keyboard cable. Luckily the computer does appear to work but of course ERROR B so I can't boot all the way.

Reading the Technical manual, they discuss the keyboard protocol. (The IR and Cable protocol is basically the same serial connection.) Does anyone know if anyone has replicated this protocol in code so we could use an ATMega to use non PC Jr keyboards with it?

And how about making the RJ11 to "pin" cable so I can try to use this thing?

Thanks!

 

[KenEG]

I recently acquired an untested PC Jr, matching monitor and the "Freeboard." It's in great shape but is missing some stuff. I was missing the power supply -- so I just went ahead and ordered AkBKukU's ATX adapter for it. When I had it open, I found it had the longboard power supply and the 64k RAM expansion. I also noticed that the IR receiver is missing ... so I have no way to use the keyboard. It came with two phone cables as if those would work with the keyboard -- but not the proper keyboard cable. Luckily the computer does appear to work but of course ERROR B so I can't boot all the way.

Reading the Technical manual, they discuss the keyboard protocol. (The IR and Cable protocol is basically the same serial connection.) Does anyone know if anyone has replicated this protocol in code so we could use an ATMega to use non PC Jr keyboards with it?

And how about making the RJ11 to "pin" cable so I can try to use this thing?

Thanks!

Check out the board at http://brutman.com. I bought an adapter that lets me use a PS2 keyboard with mine. If you really want to use the jr keyboard in wireless mode, I have an extra IR module.

 

[MikeModifed]

https://www.brutman.com/forums/viewtopic.php?f=1&t=344&p=2417&hilit=keyboard#p2417

Mike

 

[Trixter]

This is pretty slick, actually: https://texelec.com/product/ibm-pcjr-joystick-and-keyboard-breakout-board/

 

[misterblack]

Check out the board at http://brutman.com. I bought an adapter that lets me use a PS2 keyboard with mine. If you really want to use the jr keyboard in wireless mode, I have an extra IR module.

Thanks I've checked out the site now and so much useful information. (Especially the technical manual.) Do you think it's even worth trying to get IR working? I hear it's super unreliable these days especially with LED lighting and the interference it causes.

https://www.brutman.com/forums/viewtopic.php?f=1&t=344&p=2417&hilit=keyboard#p2417

Thank you for that! I think my first step is to make this cable myself to make sure that the keyboard is working. I know it's a rubber-dome setup and may need some cleaning. I didn't show in the video I put up but the IR doesn't appear to transmit from the keyboard when I shine it into my camera. So it may just be dirty like my PET was... (or dead, who knows.)

This is pretty slick, actually: https://texelec.com/product/ibm-pcjr-joystick-and-keyboard-breakout-board/

That adapter is very very cool. If I can't get my keyboard working I'll probably end up buying this adapter so I can just use a regular PS2 keyboard.

 

[MikeS]

Any interest in a NIB 'upgrade' Jr. keyboard (with the 'real' keys) ?

 

[Lutiana]

Do you think it's even worth trying to get IR working? I hear it's super unreliable these days especially with LED lighting and the interference it causes.

I would, if for no other reason than to say the system is complete. Though I found the IR connection between the keyboard and system to be relatively reliable as long as you stayed in the line of site. I tend to use the cable just so that I don't have to worry about batteries in the keyboard.

I think my first step is to make this cable myself to make sure that the keyboard is working. I know it's a rubber-dome setup and may need some cleaning. I didn't show in the video I put up but the IR doesn't appear to transmit from the keyboard when I shine it into my camera. So it may just be dirty like my PET was... (or dead, who knows.)

From what I saw in your video, it looked like there was some minor corrosion on the visible terminals (they looks white to me). So popping it open and cleaning it up might be the thing to do. As far as the cable goes, that should be pretty simple to make, you just need the pin out, which should be in the tech docs.

I'll probably end up buying this adapter so I can just use a regular PS2 keyboard.

I suggest it. The pcJR keyboard is pretty terrible to use IMO.

Welcome to the pcJR world! They are interesting machines. You may also want to look at getting a jrIDE for your system. Check it out here and here

 

[Trixter]

The jrIDE turns a PCjr from a curio into a serious machine, so if you can get one, you should.

Most people have seen the second-generation keyboard (same one as in Adrian's video). The first-generation one with "chiclet" keys is the one most people mocked, but having typed on them both for eons, I can definitely say the 1st-generation feels a lot better than the replacement. Yes, the keys are smaller, but their tactile response is much better. The 2nd-gen keyboard's keys are so hollow and flimsy that they squeak.

 

[Casey]

Check out the board at http://brutman.com. I bought an adapter that lets me use a PS2 keyboard with mine. If you really want to use the jr keyboard in wireless mode, I have an extra IR module.

Ken, I've been meaning to ask you about two adapters I've seen for the Jr. on eBay. One is for joytick & keyboard:
https://www.ebay.com/itm/TexElecs-I...bSD4o:sc:USPSFirstClass!45014!US!-1:rk:9:pf:0
The other is for serial & CGA:
https://www.ebay.com/itm/TexElecs-I...SDvC:sc:USPSFirstClass!45014!US!-1:rk:19:pf:0

Don't know if you ever encountered them before or had anything to say (good or bad) about them.

 

[Casey]

That's the one I was asking KenEG about. Hadn't seen your post. They offer a serial & CGA adapter as well. No idea if you can fit both on the back of a Jr. or not.

 

[misterblack]

Hey guys -- thanks for the advice and input. I'll be making another video about this machine and will put this in the next one --- but a few days ago I made a keyboard cable. It's sketchy but it works -- used DuPont style single connectors into the keyboard port:

https://imgur.com/a/FIbQYn8

The keyboard works perfectly! Oh and yes, as someone else said, it squeaks too LOL. Perhaps it'll get a bit better once I dismantle it and clean it up. ;-)

I really like the TexElecs adapter -- but for now I'm not quite ready to spend more than half the price I paid for the complete computer on adapter like that. I'm going to keep fiddling around and clean this up and see what I can do next with it. PicoATX supply is on the way (one that simply takes 12v input) so once I have it cleaned up it will be fun to test out what a 128k PCjr can do exactly.

Trixter, a PCjr with IDE would be very odd.

OH, I took a look on the disk that was in the computer -- and the machine definitely had a bunch of mods at once point because the disk was copying stuff to the G: drive (perhaps a ram disk as it copied command.com and then ran it from G) but also some int19jr.com or something similar that was running as a batch file on boot. I'll need to take a closer look and I'll post here to see if you guys have insight into what it was trying to do.

 

[Trixter]

Oh and yes, as someone else said, it squeaks too LOL. Perhaps it'll get a bit better once I dismantle it and clean it up. ;-)

It won't The squeak is plastic-on-plastic.

I really like the TexElecs adapter -- but for now I'm not quite ready to spend more than half the price I paid for the complete computer on adapter like that.

You found a complete PCjr + keyboard + monitor for less than $50?

Trixter, a PCjr with IDE would be very odd.

You misspelled "awesome". It's more than IDE: It provides IDE, a battery-backed clock, and upgrades the system to the maximum RAM (768KB, 640KB for DOS and 128KB for the video).

I have 8GB on one of my PCjrs using a jrIDE. It currently holds 95% of all of the software ever released that can run on a PCjr.

OH, I took a look on the disk that was in the computer -- and the machine definitely had a bunch of mods at once point because the disk was copying stuff to the G: drive (perhaps a ram disk as it copied command.com and then ran it from G) but also some int19jr.com or something similar that was running as a batch file on boot. I'll need to take a closer look and I'll post here to see if you guys have insight into what it was trying to do.

For answers to those, you might want to try the PCjr-specialized forum: https://www.brutman.com/forums/
I love the VCFED forum, but there's more PCjr-specific expertise over there.

 

[KenEG]

The adapter I was referring to was the one that just converted the keyboard port to use a PS/2 keyboard. That is what I use on mine. I haven't tried the breakout boards. I did buy the one for the video and serial port for when I get around to working on my spare PCjrs, but I haven't tried it out yet. I have at least one keyboard with cord that came with my first machine. I have to agree that the jr-IDE is an awesome addition to the machine. I think Alan is working on a new batch of them. I had two, but sold one to someone who didn't want to wait for the next batch. I just have a 12 GB DOM on mine, but on a machine from the era when 10 to 20 MB drives were common, that is plenty.

 

[Lutiana]

Trixter, a PCjr with IDE would be very odd.

I have on mine, makes the system so much better. I used a IDE to CF adapter and mounted that at the back of the shell so that the card is removable. I believe it's a 2Gb card. So much better than having to swap disks all the time.