programmable keyboard encoder - a static 80-key matrix that can be used for any application

programmable keyboard encoder elektor february 1985 The large scale integration (LSI) alphanumeric keyboard encoder ICs are now quite well known, so much so, in fact, that they have become almost classical. Their good features have been loudly heralded but they also have a number of unfavourable characteristics. The keyboard matrix is scanned at a high frequency and this causes some "pollution" in the form of HF radiation; the matrix configuration coded into ROM is fixed rigidly; there is much duplication, with the result that there are far fewer usable codes than there are positions in the matrix. These disadvantages are totally unknown to our static encoder, whose versatility enables it to be used for a wide range of applications. It permits the standard alphanumeric keyboard arrangement (QWERTY) to be implemented, of course, but it also makes it possible to use any specialised user-defined layout. programmable keyboard encoder a static 80-key matrix that can be used for any app...