networking classic hardware

Actually, it depends. One some classics, the handshaking was essentially hadnled in hardware. Write a data value to the port, and it generates a corerectly tiped sstrope. It also maes a busy signal somehow available to the host processor whcih is cleared when the hardware gets the approrate acknowledge signal from the printer. I doubt that could easily be used as a data input. The otehr odd one is the original Apple ][ parallel card. The status line Basically, it runs differnt code depending on whether the printer is ready. I supect you could do data inptu with that one byu watching one of the locations in ROM which cotnains a differnt value depending o nthe state of that address input. Sure. But a lot of classic printer prots, even if the handshake is doen in software have jsut the 7 or 8 data lines, a strobe output and a busy input. Snly one input. You could bit-back serial data over that line, I guess. I got the impression the OP didn't want to write mcuh software like that. Perhaps that's incorrect. Anyway, having a clearer idea of what the OP wants to do and what he is prepared to do (making cables, making more complex hardware, writing software, etc) would be useful. -tony