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PS/2 Keyboard Interface?


Tempest

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I was thinking the other day (a rare occurrence for me) that if I could use a PS/2 style keyboard with my TI-99 things would be a lot easier.  I never really cared for the cramped TI-99 style keyboard so anything that could expand it out a bit would be helpful.  I did some googling and saw that back in 2015 there was such a device made, but I can't find much info about it.  I'm guessing that it had issues or for some other reason didn't take the world by storm.  Is anyone still making something like this or is the idea dead?

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20 minutes ago, Tempest said:

I was thinking the other day (a rare occurrence for me) that if I could use a PS/2 style keyboard with my TI-99 things would be a lot easier.  I never really cared for the cramped TI-99 style keyboard so anything that could expand it out a bit would be helpful.  I did some googling and saw that back in 2015 there was such a device made, but I can't find much info about it.  I'm guessing that it had issues or for some other reason didn't take the world by storm.  Is anyone still making something like this or is the idea dead?

how about a USB interface?  I have those for sale

 

 

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5 minutes ago, Tempest said:

No, it needs to be to PS/2 style so I can use it with my KVM. 

Tursi designed one some years ago and it worked quite well.  you may want to reach out to  him here.  He may be willing to make one or offer the files.

 

 

gallery_35324_1358_21668.jpg

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gallery_35324_1358_1516639.jpg

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13 minutes ago, jedimatt42 said:

I believe the harmlesslion.com ps/2 keyboard adapter had no major issues. 

 

Regarding usb and ps/2 kvm, devices like this are cheap: https://smile.amazon.com/dp/B00IACID2C/ref=cm_sw_r_cp_apa_fabc_GYXGBRGR9GRXCR33NPMQ

I have a few of those laying around.  Did I misunderstand what Shift838 was saying?  Does he have a interface for the TI99 that will take a USB to PS/2 dongle and allow me to use my PS/2 keyboard with it?

How hard are these mods to install?  I haven't had the best luck opening up my TI-99 as it always seems like a puzzle when trying to get to the board underneath.   Also, assume all of these mods disable the original keyboard?

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My USB keyboard adapter(s) for the 4A take USB keyboards. The link I sent on Amazon is to a device that acts like a USB keyboard, but takes a PS/2 keyboard. It should take a KVM PS/2 output and convert to USB keyboard. And the USB to 4A adapters should accept that. I can test that in a bit. The important thing is it isn't the little adapter that switches the keyboard into USB or PS/2 mode. It actively outputs USB.

 

For an idea of what it takes to install my design: https://photos.google.com/share/AF1QipNBCeBHUqFHEIBzEKy7s_HsWHkVoXsDBwFlr_QNivTddR_SKeWeRpQ-WS83hAntyg?key=d1BOZkg2amdWQnQ1bjN0QTJjUHpDelFHSlVSUTFB

 

For general info on it: https://www.jedimatt42.com/ti99usbkeys.html

 

I believe @Shift838 was showing illustrations of this perfectly good solution: Harmlesslion.com / @Tursi keyboard adapter takes PS/2 and connects to TI keyboard connector. Design and required source code is here: http://harmlesslion.com/cgi-bin/onesoft.cgi?60

 

Both of these adapters can be connected in parallel to the just-a-bunch-of-switches that is the 4A keyboard, so both can remain active. 

 

Both are do-it-yourself projects. You can check Arcadeshopper.com to see if @arcadeshopper has any of the usb parts in stock, he has been known to carry them. I don't see any 4A oriented keyboard items in @Shift838 's store. His (PS/2|AT)->XT  adapters are Geneve oriented.

 

There is also the do-it-yourself project here: https://ti99-geek.nl/Projects/kbti994a/kbti994a.html by Fred Kaal, for USB -> 4A adaption.

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My board is plug and play, when assembled properly. You might notice that Omega didn't use the PCB. ;)

 

(Edit: I think that's an amazing build, personally, my comment was aimed more at some of my own where I cheaped out ;) ).

 

But that doesn't get you out of soldering. Someone once bought a dozen of the chips from me, but I never saw that they released any product. Nobody else ever showed any interest.

 

Edited by Tursi
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3 hours ago, Tempest said:

My soldering skills are non-existent.  Especially for small stuff.

That's fair. As Matt implied, that's probably why nobody cared about my product.

 

I tried to get a group buy put together when I released it, but nobody was interested, and I wasn't interested in selling a set until I could find the cables. I actually have a stock now of all but the power cable (which I believe can be acquired) and the keyboard cable (which I don't, a 'good enough' will be needed.)

 

Still on my todo list to revise it for serial input, so it may yet get a run, worthless or not! As a single-chip, single PCB solution, it is pretty cheap to build. I only did it to prove that yes, a keyboard adapter was that straightforward. ;)

 

 

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3 hours ago, Tempest said:

My soldering skills are non-existent.  Especially for small stuff.

If you want it soldered, I can do it for ya...

I wouldn't mind one myself, but I'm actually starting to move over to geneve for a bit and won't do any 4A stuff for awhile, but I might have to make one later.

 

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Between all the back and forth I'm getting confused (easy to do these days), so let me see if I have this straight.  There are two different models of this keyboard adapters, one by Tursi and one by jedimatt42.  Tursi's does PS/2 and jedimatt42's does USB.  Both require soldering to the board to work.  Jedimatt42's is available now online, but Tursi would need to source some parts for his.  Do I have that all correct?

 

10 hours ago, GDMike said:

If you want it soldered, I can do it for ya...

I might take you up on that offer.

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I have verified that the PS/2 to USB adapter shown in the attached photo works with Jedimatt's TI99 USB Keys.

 

Also I have been thinking of designing a new board for it that does not require any soldering.  simply plug the cable into the keyboard connector on the TI99 mainboard.

 

 

ps2tousb.png

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7 hours ago, Shift838 said:

Also I have been thinking of designing a new board for it that does not require any soldering.  simply plug the cable into the keyboard connector on the TI99 mainboard.

That would be an instant buy for me.  Any chance you could design it to be able to still use the original keyboard?

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44 minutes ago, Tempest said:

That would be an instant buy for me.  Any chance you could design it to be able to still use the original keyboard?

 

It's a tight space.  I can design the PCB to have both.  Just have to run cables and plug it in.  should be pretty simple.  

 

Be aware for the TI you will still have to connect the board to a +5v and Ground source on the TI Power supply in order to prove the required voltage to the adapter.  so there will be 2 wires that have to be soldered to the PCB of the internal power supply.  They are on pretty big pads, so it is fairly easy to do.

 

I start working on it tomorrow and see what I come up with.

 

Edited by Shift838
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