Dartmouth Time-Sharing System
time-sharing operating system
The Dartmouth Time-Sharing System (DTSS) is a discontinued operating system first developed at Dartmouth College between 1963 and 1964. It was the first successful large-scale time-sharing system to be implemented, and was also the system for which the BASIC language was developed. DTSS was developed continually over the next decade, reimplemented on several generations of computers, and finally shut down in 1999.
General Electric developed a similar system based on an interim version of DTSS, which they referred to as Mark II. Mark II and the further developed Mark III were widely used on their GE-600 series mainframe computers and formed the basis for their online services. These were the largest such services in the world for a time, eventually emerging as the consumer-oriented GEnie online service.
Background
Professors John Kemeny and Thomas Kurtz at Dartmouth College purchased a Royal McBee LGP-30 computer around 1959, which was programmed by undergraduates in assembly language. Kurtz and four students programmed the Dartmouth ALGOL 30 compiler, an implementation of the ALGOL 58 programming language, which two of the students, Stephen Garland and Anthony Knapp then evolved into the SCALP (Self Contained ALgol Processor) language between 1962 and 1964. Kemeny and freshman Sidney Marshall collaborated to create DOPE (Dartmouth Oversimplified Programming Experiment), which was used in large freshman courses.
Since the limited size of the LGP-30 (4K 31-bit words) precluded a full implementation of ALGOL 60, certain features (arrays called by value, own arrays, strings, variable array bounds, and recursion) were omitted; but the implementation did include parameters called by name, using thunks and integer labels.
ALGOL 30 was a two-pass system.
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