- ATARI Serial Input/Output (SIO) ?????????? ATARI SIO
- C64 RS232 User port Available on the Commodore C64/C128. Software emulated. The signals does not have true RS232 levels. It's TTL level, and RXD/TXD is inverted. It's just the normal User port, used as a RS232 port.
- C64 Serial I/O Available on the Commodore C64, C16, C116 and +4 computers
- CoCo Serial Printer Available on the Tandy Color Computer, also known as CoCo.
- MC-10 Serial port
- Serial (Amiga 1000)
- Serial (Amiga)
- Serial (MSX)
