UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - S-100 Light Pen System

SiriusHardware · 4th Nov 2019, 1:26 am

I'm not sure if anyone else will remember this but one of the BBC 'Micro Education' series of programs, possibly 'Micro Live', took to offering downloads of the software listings featured during the program by using a flashing dot or block in the corner of the picture and a light-pen like device to pick it up.

Presumably 'light spot' support software for each of the featured machines was available as a type-in listing or could be requested on cassette or disc, since this was all in the pre-internet age.

While not a true light pen application in the sense of using the known position of the scanning 'dot' to determine the x-y position of the tip of the 'pen', it is a different example of using a pen-like device to read the light coming off a CRT screen.

Most of those old BBC computer programmes were made available to view online on the BBC web site a while back, it might be fun to find those programmes and try to 'download' the software programmes offscreen from the online versions - it should work as long as the framerate is reasonably high, since the 'baud rate' of the flashing dot data is unlikely to have been more than about 1200 or 2400.

4th Nov 2019, 1:26 am	#5
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,570	Re: S-100 Light Pen System I'm not sure if anyone else will remember this but one of the BBC 'Micro Education' series of programs, possibly 'Micro Live', took to offering downloads of the software listings featured during the program by using a flashing dot or block in the corner of the picture and a light-pen like device to pick it up. Presumably 'light spot' support software for each of the featured machines was available as a type-in listing or could be requested on cassette or disc, since this was all in the pre-internet age. While not a true light pen application in the sense of using the known position of the scanning 'dot' to determine the x-y position of the tip of the 'pen', it is a different example of using a pen-like device to read the light coming off a CRT screen. Most of those old BBC computer programmes were made available to view online on the BBC web site a while back, it might be fun to find those programmes and try to 'download' the software programmes offscreen from the online versions - it should work as long as the framerate is reasonably high, since the 'baud rate' of the flashing dot data is unlikely to have been more than about 1200 or 2400.