ELF operating system

ELF was a real-time multi-programming operating system for the PDP-11 (hence the name - 'elf' is German for 'eleven); generally, those with PDP-11 Memory Management (both kinds). It allowed processes to be created and terminated, and allowed them access to inter-process communication and timers; allocation and freeing of main memory was also provided. It was written in assembly language; applications could also be written in BCPL and BLISS-11.

It was originally intended to allow users at terminals to simultaneously utilize time-sharing systems on the ARPANET, using NCP (use of which was a standard capability under ELF). It was a successor to ANTS in this role. It also allowed users to save files on local mass storage.

Work on it started in early 1973; it went into experimental service in early 1974, and by 1976 about 30 sites on the ARPANET were using it. It was later used by researchers at BBN to support the first routers on the experimental Internet.

See also

• Fuzzball
• MINITS
• MOS operating system

Further reading

• D. L. Retz, ELF System Development - this apparently online at Stanford, but access to it seems to currently be restricted

External links

• Structure of the ELF operating system
• ELF System Programmer's Guide
• An ARPANET Front-End for Large Computers, in Papers Presented at a Berkeley Workshop on Distributed Data Management and Computer Networks - pp. 57-70