Nascom News­let­ter

switch can be set at the junction of two tube halves to facilitate re-wiring if necessary!

It should be possible for most people to construct a light pen using the above design, though I am quite sure that most readers will be aware that this is only one way of obtaining information as to the whereabouts of the raster.

Another method could be to count the blanking pulses, or indeed build a circuit on the lines of the Nascom VIDEO RAM scanning circuitry, or buy a video board and have done with the interface problems!