Iec-Centronics Interface

EE October 1987 IEC-CENTRONICS INTERFACE by K Fietta The use of an IEC or IEEE bus for driving a Centronics compatible peripheral device calls for a special interface circuit to ensure the correct timing of handshaking signals NRFD and NDAC. The IEC bus is mainly used on minicomputers and main- frames, but is currently finding its way in some home micros also. In essence, the IEC bus is a parallel input/output port that can be adapted for use as a Centronics interface. The inter- face proposed here is a rela- tively simple type which enables driving virtually any Centronics compatible printer from an IEEE 488 bus. The IEC /IEEE 488 and Centronics interfaces have a number of technical features in common, and may be considered virtu- ally identical when used unidirectionally. In 1977, the International Elec- trotechnical Commission (IEC) published the document Stan- dard interface system for pro- grammable measuring equip- ment. This was the technical reference for the IEC interface...