* [[Cirkit serial interface]]
* [[CPCI RS232 Interface]] (DIY)
* [[KDS Electronics Serial Interface|KDS Serial Interface]] ([[KDS Electronics]])* [[SCA CPC Prolink]]* [[Simple RS232 for Printer usage]] (DIY) (one-directional, transmit only)* [[Spectre Comms Serial Interface]]* [[Schneider RS232 Interface]]
Modern: