Changes

This interface was originally described in the book "[[Maschinenspracheprogramme und Hardware-Erweiterungen für Schneider CPC's]]" written by [[Paul Bauriedl]], released by IDEA Verlag in 1987. Around mid-nineties, Tim Riemann has circulated the schematic as GIG GIF in the internet.

The circuit is very similar (or possibly nearly indentical) to the [[Schneider RS232 Interface]], both circuits are using a Z80 STI, both mapped to the same I/O port addresses. Whether or not the Both circuits are fully seem to be driven by the 4MHz signal on the CPC's expansion port, so even the the timings should be 100% compatible with each other . The only difference is '''unknown'''. Some small details might differthat the DIY circuit uses more logic chips, giving it a better (more complete) decoding of the I/O port addresses. For exampleAnother difference, concerning the clock source being passed to power supply, is that the Z80 STI chip could be differentSchneider circuit contains 2 diodes and 2 diodes for converting ~7V AC to +/-7V DC.