X.PC

X.PC is a deprecated communications protocol developed by McDonnell-Douglas for connecting a personal computer to its Tymnet packet-switched public data telecommunications network. It is a subset of X.25, a CCITT standard for packet-switched networks. It is a full-duplex, asynchronous and error-correcting network protocol that supports up to 15 simultaneous channels. It maintains automatic error correction during any communications session between two or more computers.