The Microvitec Touchtech 501 is a device that converts a monitor (Ideally a Microvitec CUB) into a touchscreen device by layering an infrared grid in front of the screen to detect the placement of a finger when it breaks the grid. It communicates with the BBC Micro via a RS423 serial connection which the BBC Micro provides as standard and uses the BBC Micro's Aux. power connector to power it.
The Microvitec Touchtech 501 was primarily used as an assistive technology within special needs schools and there was a significant amount of software written with the use of a touch screen in mind that would allow children that were unable to interact with a computer using the traditional keyboard to interact, learn and play with a computer simply by touching the screen.
In todays modern world, touch screens are everywhere and they are extremely intuitive in use. It is this ease of use which made the Microvitec Touchtech 501 an ideal way for users to interact with their computer in the mid to late 1980's and early 1990's.
Much of the software written for the Touchtech 501 was targetted at teaching children basic skills of numeracy and literacy, for instance, the mini-game "Money" shows images of 50p, 20p, 10p, 5p, 2p and 1p coins on the screen and then asks the user to choose which coins would be used to create a total value of XX pence.
e.g. To make a total of 44 pence the following coins could be used (although any valid combination would work)...
... and the user would choose the coins by touching the correct coins until the total value was reached.
There have been many papers written in the scientific community citing the use of the Touchtech in research programmes for cognitive rehabilitation after brain injury after a stroke or certain types of chemotherapy. Further studies have examined the effect of sleep depravation on cognitive abilities and how cognitive and motor abilities are affected by diseases such as Parkinson's.
Another, more fun use of the Microvitec Touchtech 501 was to couple it with the Hybrid Music System to provide a touch interface allowing the Hybrid system to be controlled with touch rather than using the BBC Micro's keyboard or the Hybrid Music 4000 keyboard. When coupled with the Hybrid Music 6000 which allowed the Hybrid system to be controlled by movement, the Microvitec Touchtech 501 completed a sensory interaction system that could be used as an effective tool within an early Snoezelen room.
Finally, here's a photo I took of the Centre for Computing History's Microvitec Touchtech 501 attached to a BBC Micro on display at the Beeb@30 event in 2012 and below it is a full screen shot of what is shown on the display.
When I got this device in February 2015 the power connector was missing from the end of the power cable. After opening up the device and examining the connections the power cable made internally to the PCB, I was able to determine that it was powered using +5V, 0V and -5V from the Aux. power connector from the BBC Micro.
From the photo above, and using continuity tests, I was able to determine that the power connections of the red, blue and green wires were connected to a bridge rectifier and ground where the green wire was 0V (GND) and the red and blue wires were +5V and -5V respectively. Once the power connections had been verified by tracing further around the PCB to determine what the power inputs of specific IC's were connected to, I confirmed the power connections as being correct so was able to successfully re-attach a power connector to the other end of the power cable so that it could be powered correctly from the BBC Micro Auxiliary power output.
Here's the pin-out for the BBC Micro Auxiliary power connector
Whilst the Touchtech was stripped down, I took the opportunity to photograph the emitters which create multiple infrared beams creating a grid that is used to determine the location of anything interrupting the infrared signals from being received by the receivers which are placed on the opposite frame of the Touchtech from the emitters.
There were several companies providing software for the Touchtech 501. The main provider for educational and special needs titles appears to have been Brilliant Computing. Other organisations including Universities and Hospitals also produced software for research and medical uses.
The Research Centre for the Education of the Visually Handicapped was associated with the University of Birmingham and produced over 12 different titles that were compatible with the Microvitec Touchtech 501.