WRITING IN LIGHT MAKES INPUT EASIER
THE SPECTRUM Lightpen by dK'tronics is a kit consisting of a tape, light pen with a 3.5mm plug on the end and a black plastic box. First you run the tape into the Spectrum; the 48K side unfortunately has the 16K version on it and vice versa so if you get out of memory, pull out the plug and start again on the opposite side of the tape.
The program loads a Basic instruction program which then loads a machine code program above RAMTOP. All goes well to that point. The instructions on the screen then warn you to plug the light pen via the control box into the computer. The power lead must be diverted through the box when you power-up the computer but the light pen must be disconnected while LOADing or SAVEing. The list of instructions is vast and all letter-coded.
Choosing a letter from the menu gives the instructions associated with that letter. Having gone through the instructions, you have to set up the delay for the screen. That is the first bit of machine code and immediately crashes the program on the 48K version. On the 16K version there is no list of instructions - they are listed in the manual.
The light pen works well; it reacts with the instructions satisfactorily. The position of its reaction can be adjusted up or down by a knob on the top of the unit. That varies the pulse sent to the EAR socket by the black box.
dK'tronics light pen costs £21.20 and is avaibble from Unit 2, Shire Hill Industrial Estate, Saffron Walden, Essex CB11 I 3AX. Tel: 0709-236350.