What is it? This is a kit which allows you to convert a (preferably non-working) Texas Instruments TI-99/4A computer from the 1980s into a USB keyboard you can use today. It will appear as a standa...

What is it?

This is a kit which allows you to convert a (preferably non-working) Texas Instruments TI-99/4A computer from the 1980s into a USB keyboard you can use today. It will appear as a standard USB keyboard device with all the keys mapped to work correctly without the need to install additional software.

The TI-99/4A has quite a nice keyboard with individual mechanical keys witches, although a limited number of keys. The FCTN key is used to replace missing keys. FCTN + number keys on the top row act like functions keys F1 through F10, FCTN + keys with symbols on the front give those keys, FCTN + keys with arrows on give cursor keys. There is no delete or backspace key marked on the keyboard, so the FCTN + the key on the top right (+/=) is used for backspace.

Why did you make it?

I repair and refurbish a lot of old computers but inevitably end up with not enough working boards and have some spare cases. These allow the case to be reused and give the look and feel of a classic machine but driving a modern computer, or there is potential to find something like a (very) small PC inside, or a Raspberry Pi or similar.

What makes it special?

No soldering or special drivers or configurations are required, just a screwdriver.

What is included?

The kit includes the USB keyboard controller PC (built, tested and programmed, ready to go), a USB cable and four mounting pillars.

What options are there?

Optionally, there is an LED cable. This replaces the original LED on the bottom right of the case which was part of the power supply PCB.

Keyboard mapping

There are two options for keyboard mapping. The normal one is for general desktop computer use, with the keys mapped so that when pressed they do what is indicated on the keycap. Additional punctuation and symbols are written on the front of the keys. To use those, press FCTN + the key, for example, FCTN + W = ~, FCTN + E = up arrow. Additionally, FCTN + F1 through F0 give F1-F10, and FCTN + the =/+ key (top right) gives backspace. Alpha lock is latching, so is used as a shift key, when pressed it is as if shift were held down, so you can type in capitals, but also you get symbols on the top row.

There is an alternative, which is suitable for use with an emulator (specifically the Classic99 emulator, others may have different mappings, so please check first). With this option, Alpha lock is used as a mode switch. When it is up (normal position), the keyboard will act as the normal desktop version described above. When it is pressed down, the keyboard is mapped for the emulator, FCTN becomes the Alt key, and all the other keys are sent directly without any remapping (with the exception of the /- key which annoyingly needs to be mapped as /? without shift and -_ when shift is pressed). If you order the LED option and the mode switch version, the power LED supplied will be tricolour, showing red in normal mode and green in emulator mode (or reverse the connector if you want that the other way around).

NO TI-99/4A COMPUTER IS INCLUDED you need to supply your own, preferably a non-working computer, but even so, please try and pass on the boards inside to someone who can make use of them.