RISC iX

Acorn chose BSD 4.3 as the basis for RISC iX due to its academic origins, these being considered as making the software more appropriate for Acorn's principal target market of tertiary education. SunOS and NeXTSTEP systems were given as examples of other "modern high-performance workstations that use BSD". Other reasons for choosing BSD included better integration of networking and connectivity tools in comparison to System V.{{ cite magazine | title=UNIX Setting Standards | magazine=A&B Computing | last1=Vogler | first1=Jon | date=March 1989 | pages=38–42 }}

• X11 (initially Release 2) with Ardent Window Manager, Tab Window Manager and Ultrix Window Manager available by default, plus X.desktop from IXI Limited{{cite book |url=http://chrisacorns.computinghistory.org.uk/docs/Acorn/Brochures/Acorn_APP214_AcornR140Workstation.pdf |title=Acorn R140 workstation in commercial and technical applications |edition=1 |date=January 1989}}
• System V virtual memory extensions, compatible with the "System V Interface Definition"
• C Compiler with ANSI C and Portable C Compiler (pcc) (Berkeley) compatibility
• Sun Microsystems Network File System version 3.2
• ARM assembly language

Although Acorn had licensed Sun Microsystems' NeWS in 1987, broad industry adoption of the X Window System, including Sun's belated endorsement, resulted in X11 technologies featuring in RISC iX.{{ cite news | url=https://archive.org/details/computerworld2117unse/page/2/mode/1up | title=Sun now shining on X-Windows standard | work=Computerworld | last1=Maginnis | first1=Ninamary Buba | date=27 April 1987 | access-date=13 February 2025 | pages=2 }} RISC iX 1.2 upgraded the X11 server to release 4, and was certified to conform to the X/Open Portability Guide 3 Base profile.{{cite news |url=https://archive.org/details/AcornUser109-Aug91/page/n8/mode/1up |title=Arc Unix at Low Cost |work=Acorn User |date=August 1991 |access-date=23 December 2020 |pages=7}}{{cite book |url=http://chrisacorns.computinghistory.org.uk/docs/Acorn/Brochures/Acorn_APP363_ComputerProductsJun91.pdf |title=Acorn Computer Products June 1991 |publisher=Acorn Computers Limited |date=May 1991 |issue=1 |access-date=16 October 2020 |pages=2}}

Peculiarly, the system console featured a two-cursor text copying mechanism inspired by Acorn's own earlier 8-bit range including the BBC Micro.{{cite book |url=https://www.4corn.co.uk/archive/docs/Acorn%20R140%20Operations%20Guide-opt.pdf |title=Acorn R140 Operations Guide |publisher=Acorn Computers Limited |date=December 1988 |issue=1 |isbn=1852500573 |access-date=17 October 2020 |pages=63 |quote=Selecting BBC mode gives you access to a very useful mechanism called cursor copy action. This was originally developed for the BBC Microcomputer, which is why it is termed BBC mode.}} One reason given for the inclusion of this feature was to be able to provide command line editing facilities for shells that did not offer it and to compensate for the exclusion of shells that did.{{rp|pages=42|quote=No doubt your UNIX will have the standard Bourne and C shells but will it have the latest Korn or Warwick shells? No to the last two. However, one of the reasons why people want those is because they can edit the command line (instead of having to type it all again) if they make an error when keying in a command. The workstation will have the much loved BBC copy key facility. You can detach the text cursor from the graphics cursor and use it to copy a previous command, modifying it as you go.}}

The system implemented transparent demand paging of compressed executable programs,{{cite news |url=https://archive.org/details/AcornUser089-Dec89/page/n67/mode/2up |work=Acorn User |title=Power to the People |author=Cox, James |date=December 1989 |access-date=6 September 2020 |pages=66–67, 69, 71}}{{rp|pages=69|q=With a relatively small disk and without drastic measures the software Acorn wished to provide would not all fit. So, Acorn introduced a data compression scheme for its executable files. This squeezes program files to half size. When a compressed program is to be run, its compressed form is copied from the disk into memory, expanded to normal size and then run.}} allowing the constituent pages of these compressed executables to be loaded into memory by the existing demand paging mechanism and then expanded in place for execution, taking advantage of the availability of sparse files (files with zero-padded regions) to reduce the disk space occupied by these pages. Shared library support, enabling processes to share library code, was also introduced to work around other "unpleasant" consequences of the hardware's 32 KB page size, one of these being the excess space occupied by processes residing in main memory, especially in situations where separate pages need to be allocated.{{cite book |chapter-url=https://archive.org/details/1991-proceedings-tech-conference-nashville/page/385/mode/1up |title=Proceedings of the Summer 1991 USENIX Conference, Nashville, TE, USA, June 1991 |publisher=USENIX Association |year=1991 |last1=Taunton |first1=Mark |chapter=Compressed Executables: An Exercise in Thinking Small |pages=385–404}}{{cite newsgroup |title=Compressed executables |date=22 January 1991 |access-date=10 October 2020 |last1=Taunton |first1=Mark |newsgroup=comp.unix.internals |message-id=4743@acorn.co.uk |url=https://groups.google.com/d/msg/comp.unix.internals/mGP6CTNdfDI/4NKaA4_rIxgJ}}

Despite these remedies, the workstations offering RISC iX were regarded as being hampered by the memory management unit (MMU) using 32 KB pages.{{cite news |url=http://chrisacorns.computinghistory.org.uk/docs/Mags/PCW/PCW_Aug90_R260.pdf |work=Personal Computer World |title=Acorn R260 |date=August 1990 |access-date=6 September 2020 |pages=148–152 |quote=A current flaw is that the 32k page size is really too big. Once paging gets going, the decline in performance is less than graceful.}} The MEMC, providing the MMU capabilities in the system architecture, was designed to be simpler to implement than contemporary MMUs,{{ cite web | url=https://sounds.bl.uk/related-content/TRANSCRIPTS/021T-C1379X0078XX-0000A0.pdf | title=National Life Stories – An Oral History of British Science – Professor Steve Furber | website=British Library | date=27 September 2013 | access-date=14 December 2024 | url-status=dead | archive-url=https://web.archive.org/web/20140808185033/https://sounds.bl.uk/related-content/TRANSCRIPTS/021T-C1379X0078XX-0000A0.pdf | archive-date=8 August 2014 }}{{rp|pages=155|quote=At that time people were beginning to adopt fairly complex memory controllers. These were things that did memory address translation through two layers of tables and they produced quite complex hardware. And I thought about this and decided I could find a much – a much simpler way of doing this.}} providing a 128-entry lookup table that effectively partitioned physical RAM into 128 equally sized pages, with a 4 MB address space divided into 128 pages resulting in the 32 KB page size employed in these systems. A "logical" or virtual page could only be usefully mapped to a single physical page through this mapping.{{ cite book | url=http://www.bitsavers.org/pdf/acorn/MEMC_Datasheet_Sep86.pdf | title=MEMC Datasheet | publisher=Acorn Computers Limited | isbn=1-85250-025-5 | date=30 September 1986 | access-date=14 December 2024 | pages=26–27 }} This approach coincidentally recreated that employed by the University of Manchester Atlas virtual memory architecture.{{rp|pages=156|quote=And unbeknown to me, I’d effectively just reinvented the very first memory management hardware that was developed for the Manchester Atlas machine, which again was based on associative memories.}}

The hardware supporting RISC iX also did not have direct memory access capabilities for disk operations, meaning that the CPU would spend time servicing interrupts related to disk transfers resulting in "a definite reduction in, but not a complete loss of, available CPU power during disk transfers".{{cite newsgroup |title=MEMC and video DMA question |date=14 February 1991 |access-date=8 January 2021 |newsgroup=comp.sys.acorn |url=https://groups.google.com/g/comp.sys.acorn/c/QvqJTOpIylU/m/4W2OYF5WXKAJ |quote=There is no separate DMA hardware for any other data traffic. The built-in ST506 controller in the A4x0/R140 has its own buffering, and the processor is required to transfer the data under interrupt on each 256-byte sector boundary, or once every 500 microseconds or so during a multi-sector transfer.}} However, by reducing the amount of data being fetched, the executable decompression technique did reduce CPU involvement in performing disk transfers, albeit at the expense of incurring CPU usage in the decompression of retrieved pages. Positive outcomes of the decompression scheme also included reduced loading on storage devices, of importance for networked storage, and generally improved disk transfer performance.

RISC iX was either supplied preinstalled on new computer hardware or was installed onsite from a portable tape drive by Granada Microcare, who would take the installation tape away with them. Upgrades to RISC iX 1.2 from earlier versions started at £349 for R140 machines, and new installations for A400-series machines started at £999. Installations required 100 MB of space on suitable hard drive or network storage, with hard drive and SCSI card bundles being offered from £1699 for R140 machines and from £2326 for A400-series machines.

Once installed a backup of the core operating system to three floppy disks was possible, allowing future reinstallation through the use of remote filesystems or backup media to transfer files to a machine.{{cite tech report |url=http://chrisacorns.computinghistory.org.uk/docs/Acorn/Misc/GrenadaReadMe.txt |title=This document gives details of the modus operandi used by the mkfloppies shell script and the three other scripts ( mkkernel, mksystem and mkarchive ) that it invokes. |publisher=Microcare Software Helpdesk |date=1 August 1990 |access-date=13 February 2021}}

File:Acorn-A680-R140.jpg

According to documentation concerning RISC iX 1.2 availability, the operating system could be used on the R140, R225 and R260, being pre-installed on the R260, accessible via a fileserver (such as an R260) on the R225, and as an upgrade from RISC iX 1.15 or earlier on the R140. The A540, being practically identical to the R260,{{cite news |url=https://archive.org/details/AcornUser100-Nov90/page/n22/mode/1up |title=Five's Alive |work=Acorn User |date=November 1990 |access-date=22 October 2020 |last1=James |first1=Paul |last2=Bell |first2=Graham |pages=21 |quote=In essence, the machine is identical to the R260 Unix workstation, but comes without Unix and without the built-in Ethernet of the latter machine.}} could support RISC iX as delivered, whereas A400-series machines required an Acorn SCSI card, with older A400-series machines also needing a memory controller upgrade and "all the appropriate field change orders" to have been performed. A300-series machines and the A3000 were not supported, largely due to potential compatibility issues with upgrades needed to bring these machines up to the required specification, in addition to operating temperature considerations with the A3000.{{cite tech report |url=http://chrisacorns.computinghistory.org.uk/docs/Acorn/Misc/a252unix.txt |title=RISCiX 1.2 Upgrade Products |publisher=Acorn Computers Limited |access-date=10 October 2020}} Subsequent Archimedes machines, such as the A5000 and A30x0 models, were introduced without any prominent indication of RISC iX compatibility, although the A5000 expansion hardware was designed to support the same form of expansion card interrupt management as the A540, R-series and A400/1-series, specifically to be able to support {{nowrap|RISC iX}}.{{ cite tech report | url=https://archive.org/details/manualzilla-id-7394047/page/5/mode/1up | title=Acorn Enhanced Expansion Card Specification | publisher=Acorn Computers Limited | date=July 1994 | access-date=30 December 2023 | issue=5 | pages=5 | quote=Some variants of the computer (Archimedes 400/1, 540, A5000 and R-Series) have extra logic on the backplane PCB, for expansion card interrupt management. The default/power on state of the logic leaves expansion card interrupts enabled, i.e. the logic can be ignored and the system will behave identically to the A300 and early A440 models. Two functions are added by the extra logic, a mask register and a status register. The logic is fitted to support RISC iX. }}

Several machines were designed specifically to run RISC iX.

An unreleased machine, built internally by Acorn for the development of RISC iX. Reputedly only two or three were built and one of them has subsequently been destroyed. All known examples are owned by The National Museum of Computing.{{ cite web | url=http://chrisacorns.computinghistory.org.uk/RISCiXComputers.html | title=RISC iX Computers | website=Chris's Acorns | date=2 May 2014 | access-date=23 January 2025 }}

Prototyped for an Olivetti product but unreleased, the A680 contained an ARM2 processor, 8 MB RAM, a 70 MB hard drive running from an onboard SCSI controller, and either a 40 MB cartridge tape drive or a single 2 MB floppy drive. Up to four "podule" expansion cards could be fitted, although one slot was occupied by the laser beam printer (LBP) expansion card supporting a directly driven low-cost laser printer as an alternative to a PostScript printer connected via the serial port.{{cite book |url=http://chrisacorns.computinghistory.org.uk/docs/Acorn/Manuals/Acorn_TechnicalPublishingSystemTRMPt1.pdf |title=Acorn Technical Publishing System Technical Reference Manual |publisher=Acorn Computers Limited |date=July 1988 |access-date=11 February 2021 |issue=B}}{{rp|pages=2}} The system was meant to run Frame Technology's FrameMaker under the "Acorn UNIX" operating system and NeWS graphical environment.{{rp|pages=4}} To support 8 MB of RAM, dual memory controller (MEMC) units were employed.{{rp|pages=10|quote=Two memory sizes are supported: 4 Mbyte (single MEMC), or 8 Mbyte (dual MEMC).}}

The A680 was reportedly the first target for RISC iX and differed in certain ways from the Archimedes and R-series models. For instance, no other machine from Acorn Computers featured integrated SCSI. However, it is rumoured that overheating from the SCSI controller was one reason for the machine to never be released.{{citation needed|date=February 2021}}

Based on the A440/1, the R140 uses the same 8 MHz ARM2 processor and 4 MB RAM, also providing a 60 MB ST506 hard drive, with the option of adding a second hard drive using the same internal controller. A SCSI adaptor was available (priced at £299 plus VAT) for other storage peripherals. Since the hardware is based on the Archimedes series, Acorn's podule expansions could be added, although appropriate drivers would have needed to be written.{{rp|pages=47|quote=All the Archimedes podules are electrically compatible but need a Unix software driver to work with the R140.}}

At the time of initial release in 1989, the cost of the R140 was £3,500 for a standalone workstation without Ethernet connectivity. For the additional cost of the Ethernet expansion (£449 plus VAT), a network-capable workstation could be configured. A floating point expansion card{{cite web |url=http://chrisacorns.computinghistory.org.uk/32bit_UpgradesA2G/Acorn_AKA20_WE32206FPCoPro.html |title=Acorn AKA20 We32206 Floating Point Co-Processor |website=Chris's Acorns |date=2 May 2014 |access-date=27 August 2021}} based on the WE32206 could also be added (priced at £599 plus VAT).{{cite book |url=http://chrisacorns.computinghistory.org.uk/docs/Acorn/Brochures/Acorn_APP221_R140ComputerSystemsJun89.pdf |title=R140 Computer Systems |publisher=Acorn Computers Limited |edition=3 |date=June 1989 |access-date=6 September 2020}} A discount introduced at the start of 1990 offered the R140 bundled with Ethernet expansion and either a 14-inch colour monitor with PC emulation software or a 19-inch monochrome monitor for £2999 plus VAT.{{cite news |url=https://archive.org/details/AcornUser091-Feb90/page/n8/mode/1up |title=Cheap Workstation |work=Acorn User |date=February 1990 |access-date=24 December 2020 |pages=7}}

Supplied with RISC OS 2 in ROM, the machine would boot that OS then could either automatically boot RISC iX totally removing RISC OS from memory or continue running RISC OS{{snd}}optionally being rebooted into RISC iX at any time.{{cite news |url=http://chrisacorns.computinghistory.org.uk/docs/Mags/PCW/PCW_Mar89_R140.pdf |title= Acorn R140 |work=Personal Computer World |date=March 1989 |access-date=23 October 2020 |last1=Redfern |first1=Andy |page=128 |quote=On switching the machine on you are booted almost instantly into RISC OS. [...] Clicking on the Unix icon activates a dialogue box asking if you really want to go into Unix or not. By clicking on the middle of this box a number of parameters can be set up. For example, you can disable RISC OS completely so that next time you switch the machine on it boots straight into Unix, or you can specify a slow boot which performs all the disk and file checking.}}

An ordinary A440/1 with at least 4 MB RAM and a suitable hard drive could also run RISC iX.

Based on the A540,{{cite book |url=http://chrisacorns.computinghistory.org.uk/docs/Acorn/Manuals/Acorn_A500R200SM.pdf |title=Acorn Archimedes 500 series Acorn R200 series Service Manual |publisher=Acorn Computers Limited |date=June 1991 |isbn=185250093X |pages=vi}} the R260 originally contained a 30 MHz ARM3 processor, 8 MB RAM (upgradable to 16 MB) SCSI adapter and a 100 MB or 120 MB{{cite book |url=http://chrisacorns.computinghistory.org.uk/docs/Acorn/Brochures/Acorn_APP480_R260.pdf |title=Acorn R260 |publisher=Acorn Computers Limited |edition=1 |date=August 1992 |access-date=8 September 2020 |pages=2}} SCSI hard drive (typically a Conner CP30100). It booted in the same style as the earlier R140, but was normally configured for customers to boot straight into RISC iX.{{cite news |url=https://vintagecomputers.sdfeu.org/mags/byte/Acorn_R260_review.pdf |title=A RISC Workstation from Acorn |work=Byte |date=December 1990 |last1=Pountain |first1=Dick |pages=72IS–15 |quote=As normally delivered to customers, though, the R260 boots straight into RISCiX multi-user mode; you never see RISC OS. To enter RISC OS, you must log out of Unix by typing halt -RISCOS.}} The machine was supplied with an Ethernet adapter.

The system was released in 1990 priced at £3995 plus VAT,{{cite news |url=http://chrisacorns.computinghistory.org.uk/docs/Acorn/NL/Acorn_NewsIss16.pdf |title=Acorn Newsletter |date=1990 |issue=16 |publisher=Acorn Computers Limited |pages=1}} having been announced with a price of £5000 plus VAT. A floating point accelerator or "arithmetic co-processor", the FPA10, was made available in 1993 for the R260, as well as for the A540 and A5000 machines, priced at £99 plus VAT. These machines were designed to support the FPA device via a dedicated socket on the processor card (or, in the case of the A5000, on the motherboard), and offered a peak throughput of 5 MFLOPS at 26 MHz.{{cite press release |url=http://chrisacorns.computinghistory.org.uk/docs/Acorn/PR/FPA_release.txt |title=Acorn Releases Floating Point Accelerator |publisher=Acorn Computers Limited |date=1993 |access-date=7 April 2021}}

A similarly configured A540 could run RISC iX. Production of the A540 and R260 was discontinued in mid-1993.{{cite news |url=http://chrisacorns.computinghistory.org.uk/docs/Acorn/SN/Acorn_SalesNews76.pdf |title=Sales News |publisher=Acorn Computers Limited |date=5 July 1993 |issue=76 |access-date=14 February 2021}}

The R225 was a diskless version of the R260. It required a network file server or an R260 to boot. The system was released alongside the R260 priced at £1995 plus VAT, having been announced with a price of £3000 plus VAT.

As well as industry-standard Ethernet, Acorn's own Econet was supported, facilitating connectivity between Econet and IP-based Ethernet networks.{{cite book |url=http://chrisacorns.computinghistory.org.uk/docs/Acorn/Brochures/Acorn_APP240_ConnectivityFromAcorn.pdf |title=Connectivity from Acorn |publisher=Acorn Computers Limited |date=September 1989 |access-date=16 October 2020 |issue=1 |pages=5 |quote=The R140, which is connected between the Ethernet and Econet networks, provides an internet routing service between the two.}} Moreover, the Econet interface on a RISC iX workstation could be treated as a "Unix networking" interface, permitting TCP/IP requests to be sent over Econet to hosts capable of handling them.{{cite tech report |url=https://www.chiark.greenend.org.uk/~theom/riscos/docs/Acorn-Unix-Econet-Device-Driver-and-Network-Device.pdf |title=Acorn Unix Econet Device Driver and Network Device |author=RISC-iX Group, Acorn Computers, Cambridge, UK |publisher=Acorn Computers Limited |access-date=16 October 2020}} In 1991, with Ethernet becoming more widespread on campus networks, Acorn offered a Network Gateway Starter Pack featuring the R140 equipped with Econet and Ethernet adapters at a price of £2499, with a licence for the TCP/IP Protocol Suite included to allow Archimedes computers to be able to communicate with such Ethernet-based networks via the gateway.{{cite news |url=https://archive.org/details/AcornUser108-Jul91/page/n11/mode/1up |title=Arc into Unix will go |work=Acorn User |date=July 1991 |access-date=3 June 2021 |pages=10}}

Similar Econet gateway capabilities were eventually extended to computers running RISC OS with Acorn's TCP/IP Protocol Suite product{{cite tech report |url=http://www.4corn.co.uk/archive/docs/AMPAPP/150/APP286%20(2nd%20ed)%20-%20World%20of%20Standards%20(1989)-opt.pdf |title=The Power of Archimedes Computers in the World of Standards: TCP/IP Protocol Suite |publisher=Acorn Computers Limited |date=August 1990 |access-date=12 March 2021 |issue=2 |quote=A gateway can be set up using either a UNIX workstation, such as an R140 or R260, or an Archimedes computer such as the 440.}} and with the broader Acorn Universal Networking (AUN) suite of technologies,{{cite press release |url=http://chrisacorns.computinghistory.org.uk/docs/Acorn/PR/AUN.txt |title=Acorn introduces Universal Networking |quote=An Acorn Universal Network can consist of a number of Econet and Ethernet networks linked together via a backbone Ethernet network using RISC OS computers as Gateway stations. These computers can act at the same time as local fileservers.}} and a device driver update eventually provided a similar means of routing TCP/IP communications over Econet networks for RISC OS machines.{{cite press release |url=http://chrisacorns.computinghistory.org.uk/docs/Acorn/PR/New_EconetA_module_available.txt |title=New EconetA module available |publisher=Xemplar Education Limited |quote=EconetA is a driver module that allows Econet and Nexus client computers to act as full TCP/IP clients as well as enabling gatewaying between the above systems and standard Ethernet installations.}}

In 1989, Acorn announced support for the R140 from a number of application software vendors, including Informix, along with applications such as Uniplex, Q-Office (from Quadratron), Tetraplan, Sculptor (from MPD), Sea Change (from Thomson),{{cite news |url=https://archive.org/details/AcornUser081-Apr89/page/n8/mode/1up |title=Informix signs up for R140 |work=Acorn User |date=April 1989 |access-date=23 October 2020 |pages=7}} Recital ("a dBase compatible relational database") and Q-Calc ("a Lotus, key-compatible spreadsheet").{{cite news |url=https://archive.org/details/AcornUser085-Aug89/page/n10/mode/1up |title=Acorn Unix puts on a good show |work=Acorn User |date=August 1989 |access-date=1 November 2020 |pages=7}} Applications for school administration and financial management - SIMS and SCRIPT (a COBOL-based school administration system{{cite news |url=https://archive.org/details/Archive_1990-05_OCR/page/n41/mode/2up |title=Some Thoughts on Unix |work=Archive |date=May 1990 |access-date=10 April 2021 |last1=Lynch |first1=Ian |pages=40–41}}) - were also offered in a bundle with the R140 workstation.{{cite news |url=https://archive.org/details/AcornUser083-Jun89/page/n16/mode/1up |title=Unix for schools |work=Acorn User |date=June 1989 |access-date=23 October 2020 |pages=15}} The database application development tool DataFlex was announced for the R140 in mid-1990.{{cite news |url=https://archive.org/details/AcornUser096-Jul90/page/n10/mode/1up |title=R140 Applications Made Easy |work=Acorn User |date=July 1990 |access-date=6 May 2021 |pages=9}}

Despite Acorn stating an intention to offer a Unix system from as early as 1982,{{cite news |url=https://archive.org/details/AcornUser001-Jul82/page/n7/mode/1up |work=Acorn User |title=National Semiconductor Deal |date=July–August 1982 |access-date=1 September 2020 |pages=4}} with the National Semiconductor 32016 platform being the proposed vehicle for such a product, technical difficulties with the 32016's chipset led to the Acorn Cambridge Workstation - the surviving product from the Acorn Business Computer range - shipping with a proprietary Acorn operating system instead of the planned Xenix-based Unix offering.{{cite news |url=https://archive.org/details/AcornUser037-Aug85/page/n8/mode/1up |work=Acorn User |title=Workstation puts power on desks |date=August 1985 |access-date=30 August 2020 |pages=7, 11}}

With the development of the ARM chipset, however, Acorn was finally in a position to deliver its own system capable of running Unix, announcing work as early as the autumn of 1987 on an "upmarket ARM-based workstation to run the Unix operating system" for release in mid-1988 to compete with Sun and Apollo models in the higher education market, featuring a built-in WE32206 "arithmetic co-processor".{{cite news |url=https://archive.org/details/AcornUser064-Nov87/page/n10/mode/1up |title=Acorn 'disappointed' by £1.4 million loss |work=Acorn User |date=November 1987 |access-date=16 April 2021 |pages=9}} The company eventually brought the R140 to market in early 1989 alongside the second iteration of ARM2-based Archimedes 400-series models, following up in 1990 with the R225 and R260 alongside the high-end, ARM3-based Archimedes 540, thereby delivering on their earlier ambitions within the space of a couple of years. The introduction of the R225 and R260 renewed the enthusiasm of some commentators who conceded that the earlier ARM2-based R140, alongside competition based on the 80386, 68020 and 68030 processors, were underpowered to run "wedding-cake configurations" of the X Window System, Motif, X.desktop and other software, but considered Acorn's ARM3 products, alongside competition based on the 80486, SPARC and 88000 processors, to be more capable of such tasks.{{ cite magazine | title=Acorn's workstations enter the big league | magazine=A&B Computing | last1=Vogler | first1=Jon | date=September 1990 | pages=10 }}

Nevertheless, Acorn discontinued R260 production in 1993, shortly after announcing the floating point accelerator unit,{{cite news |url=http://chrisacorns.computinghistory.org.uk/docs/Acorn/SN/Acorn_SalesNews75.pdf |title=Sales News |publisher=Acorn Computers Limited |date=29 June 1993 |issue=75 |access-date=14 February 2021}} which had been promised for 1991 and repeatedly delayed,{{cite news |url=https://archive.org/details/Risc_User_Volume_5_Issue_10_1992-10_BEEBUG_GB/page/n55/mode/1up |title=A Plea to Acorn |work=Risc User |last1=Crennel |first1=Kate |date=October 1992 |access-date=10 April 2021 |volume=5 |issue=10 |pages=56}} and subsequently offered no new RISC iX system products. Although there were expectations that Acorn's corporate parent, Olivetti, might have provided opportunities for ARM-based Unix workstation products, leveraging its relationship with AT&T as the proprietor of Unix, it became apparent that AT&T's own interests lay with products based on the SPARC architecture,{{cite news |url=https://archive.org/details/AcornUser066-Jan88/page/n14/mode/1up |title=Competition hots up for Unix on RISC |work=Acorn User |date=January 1989 |access-date=28 March 2021 |pages=13}} with AT&T also having an ownership stake in Sun.{{ cite magazine | url=https://archive.org/details/sim_computerworld_1988-09-05_22_36/mode/1up | title=Sparcs flying over RISCy turf | magazine=Computerworld | last1=Margolis | first1=Nell | date=5 September 1988 | access-date=23 February 2023 | pages=1 }} Olivetti's own workstation strategy was incoherent at the turn of the 1990s, with the company announcing products based on MIPS and Alpha architectures before settling on Intel's architecture once again.{{ cite magazine | url=https://archive.org/details/sim_electronic-news_1993-09-13_39_1980/page/n13/mode/1up | title=Data Topics | magazine=Electronic News | date=13 September 1993 | access-date=20 June 2022 | pages=14 }}

File:RISCiX performance.svg

Olivetti itself had previously made a workstation, the CP486, based on the Intel 80486 running SCO Unix or Xenix and offering support for the Weitek 4167 floating point unit and Intel i860 "application accelerator". This machine was available in 1989 and described as the basis of a "high-cost authoring workstation" in a European initiative,{{cite web |url=http://research.cs.ncl.ac.uk/cabernet/www.laas.research.ec.org/esp-syn/text/2105.html |title=Multimedia Integrated Workstations |website=IST NoEs Information Service |date=December 1993 |access-date=25 September 2021}} but was rather more expensive than Acorn's RISC iX workstations, costing $16,250 for a configuration with 4 MB of RAM and 150 MB hard disk.{{cite magazine |url=https://archive.org/details/sim_personal-workstation_1990-01_2_1/page/41/mode/1up |title=Cheetah and Olivetti 486s |magazine=Personal Workstation |date=January 1990 |access-date=27 November 2021 |last1=Rinko-Gay |first1=William L. |pages=41–44}} Crude hardware performance comparisons based on Dhrystone benchmarking under like-for-like environments - taking results from CP486 benchmarks run under DOS and from Archimedes benchmarks run under RISC OS{{cite web |url=https://stardot.org.uk/forums/viewtopic.php?p=286141#p286141 |title=Benchmarks |website=stardot.org.uk |date=6 May 2021 |access-date=24 August 2021 |last1=Walker |first1=Sarah}} - indicate that the CP486 was around four times faster than the R140 and was still faster than the R260. Floating-point arithmetic performance of the CP486 was approximately double that of the R260 with FPA fitted. Of more relevance to RISC iX itself, in the context of the workstations developed for European initiatives, the Chorus system was to be used as the basis of the Unix operating system provided, both on the 486-based authoring workstation and the ARM3-based "low cost delivery workstation",{{ cite journal | url=https://archive.org/details/sim_world-publishing-monitor_1991-08_1_8_0/page/725/mode/1up | title=Europe United with Multimedia | journal=Open Syst. | volume=2 | issue=5 | date=5 June 1991 | access-date=13 June 2022 | last1=Davidson | first1=C. | pages=28–30 }}{{ cite journal | url=https://archive.org/details/ICL-Technical-Journal-v07i02/page/288/mode/2up | title=An Overview of Multiworks | journal=ICL Technical Journal | last1=Morris | first1=M. E. | last2=Cole | first2=I. | date=November 1990 | access-date=30 May 2024 | volume=7 | issue=2 | pages=288–295 }} with Chorus having been ported to the ARM3 processor.{{cite news | url=https://www.newspapers.com/clip/79844445/ | title=Microfile: Chorus line-up | author-first=Jack | author-last=Schofield | newspaper=The Guardian | location=London | date=10 January 1991 | page=31 (Computer) | via=Newspapers.com}}

In computational performance terms, Acorn's R140 compared unfavourably with other 1989 models such as the Sun SPARCstation 1{{ cite magazine | url=https://archive.org/details/sim_unix-review_1989-11_7_11/page/n114/mode/1up | title=Tested Mettle: Sun Microsystems' SPARCstation 1 (the Sun-4/60) | magazine=UNIX Review | date=November 1989 | access-date=30 January 2023 | last1=Wilson | first1=David | pages=109, 111–116, 118–120 }} and Digital DECstation 3100,{{ cite magazine | url=https://archive.org/details/sim_unix-review_1989-10_7_10/page/n126/mode/1up | title=Tested Mettle: Digital's DECstation 3100 | magazine=UNIX Review | date=October 1989 | access-date=30 January 2023 | last1=Wilson | first1=David | pages=121, 123–132, 135 }} particularly with regard to floating-point performance, although such disadvantages could perhaps have been somewhat overlooked in an entry-level workstation costing around {{nowrap|£4,000}} or approximately ${{FormatNum:{{ToUSD|4000|GBR|year=1989|round=yes}}}}, compared to {{nowrap|$12,620}} for the DECstation 3100, or {{nowrap|$7,995}} for the entry-level DECstation 2100. The R260 compared more favourably in terms of integer performance with its contemporaries employing processors such as the Intel 486 and Motorola 68030, but comparing less favourably with 68040-based models and newer models from traditional RISC workstation vendors.{{ cite magazine | url=https://archive.org/details/sim_unix-review_1991-05_9_5/page/63/mode/1up | title=Tested Mettle: Hewlett-Packard 9000/425t | magazine=UNIX Review | date=May 1991 | access-date=30 January 2023 | last1=Wilson | first1=David | pages=63–67 }} In terms of pricing, although the R260 maintained a similar price point to the R140, increasing pricing competition between Digital and Sun brought models like the DECstation 2100 down to {{nowrap|$5,950}} even before the R260's introduction at an already reduced price of {{nowrap|£3,995}}, equivalent to ${{FormatNum:{{ToUSD|3995|GBR|year=1990|round=yes}}}}.{{ cite magazine | url=https://archive.org/details/sim_computerworld_1990-05-07_24_19/page/n7/mode/1up | title=Sun to lower stakes with Sparc entry | magazine=Computerworld | last1=Daly | first1=James | date=7 May 1990 | access-date=14 November 2023 | pages=1, 8 }} At the point of the introduction of floating-point hardware for the R260 in 1993, the performance of the R260 was decidedly uncompetitive with the final MIPS-based DECstation models and contemporary SPARCstation models.{{ cite magazine | url=https://archive.org/details/sim_unix-review_1993-01_11_1/page/n58/mode/1up | title=Tested Mettle: The Sun SPARCstation 10: Models 30 and 41 | magazine=UNIX Review | date=March 1993 | access-date=30 January 2023 | last1=Wilson | first1=David | pages=51–57 }}

In 1994, the Risc PC launched with an improved chipset that was amenable to running Unix, and amidst a certain level of interest in the "large potential" of Unix running on the new machine,{{cite newsgroup |url=https://groups.google.com/g/comp.sys.acorn/c/k0cd74iJAvQ/m/Kcw6Eu8PRwsJ |title=UNIX on RiscPC's ???? |newsgroup=comp.sys.acorn |date=21 April 1994 |access-date=14 February 2021}} the independent RiscBSD initiative was announced in August 1994 to bring "a base of BSD4.4 - probably the NetBSD flavour" to this hardware platform.{{cite newsgroup |url=https://groups.google.com/g/comp.sys.acorn/c/G19nI9eac-o/m/qJhAOaV4-u0J |title=RiscBSD: UNIX for the Risc PC |newsgroup=comp.sys.acorn |date=15 August 1994 |access-date=14 February 2021}} A "very, very alpha kernel" was demonstrated after six weeks of initial effort by the RiscBSD developers at the Acorn World show in late 1994. Meanwhile, another initiative, ArcBSD, sought to port FreeBSD to "all 32-bit Acorn machines with sufficient RAM and hard disk space".{{cite news |url=https://archive.org/details/AcornUser152-Feb95/page/n82/mode/1up |title=Postcards from the edge, part 2 |work=Acorn User |date=February 1995 |access-date=24 July 2021 |last1=Walker |first1=Dave |pages=83}}

Although not developed with any significant Acorn involvement, RiscBSD eventually became NetBSD/arm32 (being imported in NetBSD 1.2{{cite web |url=https://www.netbsd.org/changes/changes-1.2.html#port-arm32 |title=Significant changes from NetBSD 1.1 to 1.2 |website=NetBSD |access-date=16 February 2021}}) and was used in a Risc PC-based product sold by Acorn's education joint venture, Xemplar, called NCServer.{{cite web |url=http://www.precedence.co.uk/news/timewarp/ |title=It was 20 years ago today... |website=Precedence Technologies |last1=Borrill |first1=Stephen |date=19 October 2016 |access-date=14 February 2021}} Support for this product continued after the Apple takeover of Xemplar in 1999 through a company, Precedence Technologies, founded to continue development having acquired the remaining network computer inventory.{{cite conference |url=https://www.bsdcan.org/2009/schedule/attachments/77_BuildingProductsWithNetBSDthin-clients-Stephen-Borrill.pdf |title=Building products with NetBSD - thin-clients |last1=Borrill |first1=Stephen |conference=BSDCan 2009 |date=8 May 2009 |access-date=14 February 2021}}{{cite news |url=https://archive.org/details/AcornUser236-Aug01/page/n51/mode/1up |title=Why use lazy old FAT clients, when you can have fast and efficient THIN clients? |work=Acorn User |date=August 2001 |access-date=19 May 2021 |pages=52}} The product evolved to employ server hardware based on the Simtec CATS board, providing access to files and applications stored on the server via an HTML-based interface, with RISC OS-based network computers being able to run the NCWorks suite of applications customised from various familiar RISC OS applications such as Draw, Paint, EasiWriter, DataPower and Schema.{{cite news |url=https://archive.org/details/AcornUser229-Jan01/page/n60/mode/1up |title=Secret societies |work=Acorn User |date=January 2001 |access-date=26 July 2021 |last1=Skegg |first1=Richard |pages=61–63}} NetBSD support for Acorn machines was eventually provided by the acorn32 port for Risc PC and A7000 family models,{{ cite web | url=https://wiki.netbsd.org/ports/acorn32/ | title=NetBSD/acorn32 | website=NetBSD | date=2 June 2019 | access-date=8 August 2022 }} along with the acorn26 port for Archimedes, A-series and R-series models, thus bringing a more modern Unix variant to Acorn's original Unix workstations.{{ cite web | url=https://wiki.netbsd.org/ports/acorn26/ | title=NetBSD/acorn26 | website=NetBSD | date=2 June 2019 | access-date=8 August 2022 }}

{{Reflist}}

{{Acorn computers}}

{{Unix-like}}

{{DEFAULTSORT:Risc Ix}}

Category:Acorn Computers operating systems

Category:ARM operating systems

Category:Berkeley Software Distribution

Category:Discontinued operating systems

Category:1988 software