Idris is a discontinued multi-tasking, Unix-like, multi-user, real-time operating system released by Whitesmiths, of Westford, Massachusetts. The product was commercially available from 1979 through 1988.

Background

Idris was originally written for the

PDP-11 The PDP-11 is a series of 16-bit minicomputers sold by Digital Equipment Corporation (DEC) from 1970 into the 1990s, one of a set of products in the Programmed Data Processor (PDP) series. In total, around 600,000 PDP-11s of all models were sold, ...

by P. J. Plauger, who started working on Idris in August 1978. It was binary compatible with Unix V6 on PDP-11, but it could run on non- memory managed systems (like LSI-11 or PDP-11/23) as well. The kernel required 31 KB of RAM, and the C compiler (provided along with the standard V6 toolset) had more or less the same size.

Ports

Although Idris was initially available for the PDP-11, it was later ported to run on a number of platforms, such as the VAX,

Motorola 68000 The Motorola 68000 (sometimes shortened to Motorola 68k or m68k and usually pronounced "sixty-eight-thousand") is a 16/32-bit complex instruction set computer (CISC) microprocessor, introduced in 1979 by Motorola Semiconductor Products Sector ...

, System/370 and

Intel 8086 The 8086 (also called iAPX 86) is a 16-bit microprocessor chip designed by Intel between early 1976 and June 8, 1978, when it was released. The Intel 8088, released July 1, 1979, is a slightly modified chip with an external 8-bit data bus (allowi ...

. There was also a version that used bank-switching for memory management, that ran on the Intel 8080. In 1986, David M. Stanhope at

Computer Tools International A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as programs. These program ...

ported Idris to the

Atari ST The Atari ST is a line of personal computers from Atari Corporation and the successor to the Atari 8-bit family. The initial model, the Atari 520ST, had limited release in April–June 1985 and was widely available in July. It was the first pers ...

and developed its

ROM Rom, or ROM may refer to: Biomechanics and medicine * Risk of mortality, a medical classification to estimate the likelihood of death for a patient * Rupture of membranes, a term used during pregnancy to describe a rupture of the amniotic sac * R ...

boot cartridge. This work also included a port of X to Idris. Computer Tools and Whitesmiths offered it to

Atari Atari () is a brand name that has been owned by several entities since its inception in 1972. It is currently owned by French publisher Atari SA through a subsidiary named Atari Interactive. The original Atari, Inc. (1972–1992), Atari, Inc., ...

as a replacement for

Atari TOS TOS (The Operating System) is the operating system of the Atari ST range of computers. This range includes the 520ST and 1040ST, their STF/M/FM and STE variants and the Mega ST/STE. Later, 32-bit machines ( TT, Falcon030) were developed using a ...

, but eventually marketed it directly to ST enthusiasts. A specific version of Idris (CoIdris) was packaged as a

.COM file A COM file is a type of simple executable file. On the Digital Equipment Corporation (DEC) VAX operating systems of the 1970s, .COM was used as a filename extension for text files containing commands to be issued to the operating system (si ...

under DOS and used it for low level I/O services. Idris was ported to the Apple Macintosh (as MacIdris) by John O'Brien (of Whitesmiths Australia) and remained available until the early 1990s. MacIdris ran as an application under the Finder or Multifinder.

MacWorld ''Macworld'' is a website dedicated to products and software of Apple Inc., published by Foundry, a subsidiary of IDG Inc. It started life as a print magazine in 1984 and had the largest audited circulation (both total and newsstand) of Macint ...

November 1989, page 1
quoted
in comp.sys.mac After Whitesmiths had been merged with Intermetrics, Idris along with its development toolchain was ported by Real Time Systems Ltd to the INMOS T800 transputer architecture for the

Parsytec ISRA VISION PARSYTEC AG is a company of ISRA VISION AG and was founded in 1985 as Parsytec (PARallel SYstem TEChnology) in Aachen, Germany. Parsytec has become known in the late 1980s and early 1990s as a manufacturer of transputer-based paralle ...

SN1000 multiprocessor.

References

{{Unix-like Discontinued operating systems PDP-11 Unix variants 68k architecture