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A PS/2 Keyboard on a TI-99/4A (Updated 1/6/2018)

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In the early 80's, keyboards on 'lower-end' computers left many users wanting improvement. The TI-99/4A did not have the worst keyboard out there, but there was still room for improvement. One company of the era took up the challenge, but I'm sorry to say, it missed the mark a little...




Image of Rave keyboard 'liberated' from: << this Mainbyte article >>.

The Rave keyboard was an improvement of sorts, but the technology of the time was larger, requiring that the user remove the TI's keyboard. The connector on the Rave keyboard also stuck up like a sore thumb, and in my opinion, ruined the TI's sleek looking appearance.


A few years back, one of the TI-Gods known as "Tursi" designed a neat little keyboard adapter that was small enough to fit inside the TI... with the keyboard! If that's not enough, you even have the flexibility of mounting your connector anywhere you want. If you would like to read more about this device on Tursi's website, go

<< HERE >>.


Here are some closeup views of the device I'm using in my TI-99/4A...






After you install the device, your TI will pretty much look the same, with the exception of the connector. I mounted mine on the left-hand side near the rear of the computer as seen in this photo below.




If you want to see all the photos of this project, go to my gallery entry << HERE >>


I've made up a couple of PS/2 keyboard overlays, available for download in the attachment below. These two photos will give you an idea of what they look like in use.


First version (single row)



Second version (three row)



This turned out to be one of the nicest upgrades ever, which was a little unexpected, but after I started using it, it all made sense. You see, the TI console is not the easiest to move around or into a good position, with the 'fire hose', monitor cable and power cables ALL hanging off the unit. The PS/2 keyboard uses one little cable and can easily be moved around, and after all these years, most of us are used to PC keyboards.


This is an upgrade/modification that I recommend to anyone who is not a purist that requires a stock system. After all these decades, the TI is still evolving and improving.





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I notice you have the right angle connector on the board for attaching the internal keyboard; does this work?

(In his docs with the hex file etc. he said he had not tested if it would interfere).

I figure as long as you are not using both keyboards at the same time, i.e. pushing buttons on each at once, it should work fine.


The question is have you tried it and does it?



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Yes, it does work! :)


Without the connector at that angle the TI's keyboard would not be able to plug in and remain in the case.


The orientation of the unit is actually 'upside down' inside the case. I used black electrical tape on the metal 'clam shell' where the unit sits so there would not be any accidental electrical conductivity issues.


Yes, you CAN use both keyboards at the same time... BUT...


1) Always have the CAPS LOCK on the TI's keyboard in the off

position at all times.


2) Caps lock is controlled by the PS/2 unit. Every time you turn on the

computer it defaults to ON, so you'll have to get in the habit of

turning it off if you plan to use the joystick.

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I love it, it works great and I've had absolutely no problems whatsoever with it except for some a bounce issue in TI Pinball.


It's been on Ksarul list of things to do. You could wait, or you might want to consider an alternative of the 'wireless variety'. It might be more difficult to install, and I have no clue how expensive it's going to be, but you can

<< CLICK HERE >> to go to the thread that has more information on it.


BTW - Are you planning on coming to TI Fest West 2016?

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