Stream Input-Output System g Overview s Queues Message blocks Scheduling Flow Control Messages Queue Mechanisms and Interfaces Connection with the Rest of the System s Interprocess Communication Evaluation s Blit Datakit pseudo-terminal inter-process communication g character device control blocks control messages data blocks data messages kill processing line disciplines message module s PT files f put procedure s queue module s remote program remote file transfer server routines service procedure s stream I/O s stream device s stream modules s stream processing modules s terminal device terminal input terminal module s terminal processing module s top-level routines s user process s user program s ioctl S device driver I init S I close S I stream S I read S I write S virtual terminal s pseudo-terminal s