digitizer - the outside link

Communication with the outside world is vital for a computer, but most information from that outside world arrives in analogue, that is, continuously varying, form rather than as a series of binary digits, bits, which are the computer"s staple diet. The continuously varying signals can be converted into bits by the digitizer presented here. The pcb on which the digitizer is housed fits nicely onto the versatile input output bus featured elsewhere in this issue. It comprises a single analogue/digital converter IC, the input of which is connected via software to one of the eight analogue input terminals on the pcb. Operation is simple and effected by BASIC with a single peek and poke command. digitizer the outside link The layout of the digitizer is fairly simple; yet, its performance is excellent. The printed circuit board (pcb) has eight input terminals, to each of which an analogue signal may be applied. A poke command in BASIC enables the selection of one of the eight input pins...