ARX (operating system)

According to the project Application Manager[https://www.realworldtech.com/forum/?threadid=96764&curpostid=96801 TOP3 smart moves] Richard Cownie. Real World Technologies (September 2009) Richard Cownie, during the project, while Acorn was developing the kernel, it used the C and Acorn Modula Execution Library (CAMEL) in the Acorn Extended Modula-2 (AEM2) compiler (ported from Modula-2 ETH Zurich (ETH) using Econet hardware). Though never released externally, CAMEL was ported to use on Sun Microsystems Unix computers.{{Cite web

| url=http://chasewoerner.org/resume.html

| title=David Chase (resume)

| last=Chase |first=David

| access-date=2015-10-25

}} In an effort to port Sun's workstations Sun NeWS to the Archimedes, David Chase developed a compiler based on AEM2 for the programming language Modula-3.{{Cite journal

| doi = 10.1145/99278.99285

| volume = 15

| issue = 6

| pages = 66–76

| last = Jordan

| first = Mick

| title = An extensible programming environment for Modula-3

| journal = SIGSOFT Software Engineering Notes

| access-date = 2009-09-08

| year = 1990

| url = https://www.cs.tufts.edu/~nr/cs257/archive/mick-jordan/modula-3-environment.pdf

}}

ARX was a preemptive multitasking, multithreading, multi-user operating system. Much of the OS ran in user mode and as a result suffered performance problems due to switches into kernel mode to perform mutexes, which led to the introduction of the SWP instruction to the instruction set of the ARMv2a version of the ARM processor. It had support of a file system for optical (write once read many (WORM)) disks and featured a window system, a window toolkit (and a direct manipulation user interface (UI) editor{{Cite web

|title=Brian T. Lewis - Resume

|access-date=2010-12-26

|url=http://pages.sbcglobal.net/btlewis/resume-formatted.html

|archive-url=https://web.archive.org/web/20040501210222/http://pages.sbcglobal.net/btlewis/resume-formatted.html

|url-status=dead

|archive-date=2004-05-01

}}) and an Interscript-based text editor, for enriched documents written in Interpress (a HTML precursor). The OS had to be fitted in a 512 KB read-only memory (ROM) ROM image.{{Cite web

| title=Full Acorn Machine List

| access-date=2010-12-27

| url=http://www.khantazi.org/Archives/MachineLst.html#A500

}} This suggests that ARX had a microkernel-type design.{{According to whom|date=April 2021}}

It was not finished in time to be used in the Acorn Archimedes range of computers, which shipped in 1987 with an operating system named Arthur, later renamed RISC OS, derived from the earlier Machine Operating System (MOS) from Acorn's earlier 8-bit BBC Micro range.{{Cite web |url=http://neil.franklin.ch/Usenet/alt.folklore.computers/20010824_Not_A_RISC_By_Thursday |title=Not A RISC By Thursday |last1=Holgate |first1=Chris |last2=Davison |first2=Rob |last3=Burke |first3=Stephen |last4=Given |first4=David |last5=Harris |first5=Ben |last6=Kendrick |first6=Rob |last7=Bracey |first7=Kevin |last8=Fenelon |first8=Pete |last9=Blunt |first9=Terry |author10=druck |last11=Markettos |first11=Theo |last12=Kossow |first12=Al |last13=Zuschlag |first13=Jesper |last14=Barclay |first14=Alan |last15=Crocker |first15=Stephen |last16=Pampling |first16=Steven |display-authors=et al. |website=Neil Franklin's Usenet Archive |access-date=2020-02-07}} A set of Usenet posts detailing why ARX was abandoned for RISC OS. Confusion persisted about the nature of ARX amongst the wider public and press, with some believing that ARX was Acorn's own Unix variant,{{ cite news | url=https://archive.org/details/Archive_1988-02_OCR/page/n51/mode/1up | title=Fact or fantasy? | work=Archive | date=February 1988 | access-date=30 April 2021 | pages=50 }} with this view being refined in time to accommodate ARX as Acorn's own attempt to deliver a "UNIX look-alike" whose development had been abandoned in favour of a traditional Unix version for the Archimedes, which ultimately emerged as RISC iX.{{ cite news | url=https://archive.org/details/eu_RiscUser_1988-09_OCR/page/n43/mode/1up | title=PC Emulator and Arthur | work=RISC User | date=September 1988 | access-date=30 April 2021 | pages=44 }}

The Acorn Research Centre was acquired by Olivetti.

• RISC iX

{{Reflist}}

• [http://lists.cloud9.co.uk/pipermail/bbc-micro/2010-January/007795.html ARX features]
• [http://www.chiark.greenend.org.uk/~theom/riscos/docs/ultimate/a252swp.txt History of the addition of the SWP instruction to the ARM3 instruction set]

{{Acorn computers, clones and compatibles}}

{{Unix-like}}

{{Mach-like}}

{{Microkernel}}

{{DEFAULTSORT:Arx (operating system)}}

Category:Acorn Computers operating systems

Category:ARM operating systems

Category:Discontinued operating systems

Category:Microkernel-based operating systems

Category:Microkernels