Centronics Monitor

CENTRONICS MONITOR A. Rigby The Centronics interface standard is often said to be without problems in practical use. When a malfunction occurs, however, many more connections have to be checked than, for instance, on an RS-232 link. The monitor described here alleviates the plight in debugging a Centronics connection. It is a handy tester that indicates the levels on all lines simultaneously, including those that carry pulses. Nearly all of today"s personal computers are equipped with a Centronics port for connecting a printer. The general accept- ance of the Centronics interface standard has been helped by the availability of ready-made cables of various lengths, and the fact that the majority of printer manu- facturers have ensured compliance with the pinning of the "blue-ribbon" input con- nector on their products. Sometimes, however, the installation of a new printer or cable gives rise to awkward problems that take a lot of precious time to analyse and resolve. In these cases...