* [[Amstrad Serial Interface]] ([[Amstrad]])
* [[Cirkit serial interface]] ([[Cirkit]])
* [[CPC Booster|CPC Booster/CPC Booster+]] (modern multifunction expansion, including RS232)
* [[CPCI RS232 Interface]] (DIY)
* [[Data Media Disc System]] (disc drive with built-in RS232 interface) ([[Data Media]])