Editing Risc PC (section)

== Technical specifications ==
[[File:riscpc internal.jpg|thumb|Risc PC with lid removed, showing fixing lugs. The top slice has not been internally sprayed for RF shielding.]]
[[File:Acorn-Risc-PC-ARM710-CPU.jpg|thumb|An ARM 710 CPU card for the Risc PC]]
[[File:Acorn ACA56 Risc PC x86 Card box open.jpg|thumb|The Acorn ACA56 Acorn PC card upgrade, showing the user guide, software disc, and card itself]]
{{unordered list
| '''CPU''': Dual-processor slots, one host processor and one guest processor.
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| '''Host processors''':
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| [[ARM architecture|ARM]]610 at 30&nbsp;MHz or 33&nbsp;MHz
| ARM710 at 40&nbsp;MHz
| [[StrongARM]] at 203&nbsp;MHz, 236&nbsp;MHz or 300&nbsp;MHz.
| Additionally prototypes of 33&nbsp;MHz ARM700 and 55&nbsp;MHz ARM810 processors were developed by Acorn, but not released.}}
| '''Guest processors''':
{{unordered list
| [[Intel 80486|486]]-class<ref name="independent holds right cards">{{cite news | url=https://www.independent.co.uk/extras/indybest/gadgets-tech/computers-system-that-holds-the-right-cards-1370124.html | title=Computers: System that holds the right cards | work=[[The Independent]] | date=1994-04-15 | access-date=6 September 2011 | author=Penman, Danny | location=London | quote=The modular design of the new computer allows a PC 486 processor to be added using a card ...}}</ref> and at least [[IBM 5x86C]]<ref>{{Cite web|url=https://www.ebay.com/itm/Used-Acorn-586-ACA57-Risc-PC-IBM-5x86C-100MHz-Second-Generation-PC-Card-/172405511966|title=Used Acorn 586 ACA57 Risc PC IBM 5x86C 100MHz Second Generation PC Card|website=eBay|language=en|quote=IBM 5x86C 100MHz Second Generation PC Card|access-date=2017-11-08}}</ref> co-processors at up to 133&nbsp;MHz. These ''PC cards'' and software allow PC compatible software to be run.
| [[digital signal processor|DSP]] chips (third party) were also available.{{Citation needed|date=February 2014}}}}}}

| '''Memory type''': Two 72-pin FPM [[SIMM]] slots, supporting a maximum memory size of 256&nbsp;MiB.
| '''Video subsystem''': [[VIDC20]] controller, with optional dual-port VRAM up to 2&nbsp;MiB.<ref name="apdl acorn appnote 254">{{cite web|title=APDL RiscWorld|url=http://www.apdl.org.uk/riscworld/volumes/volume4/issue4/makemode2/index.htm|work=Application Note 254|publisher=[[Acorn Computers]]|access-date=30 August 2019|date=9 June 2003}}</ref>
| '''Expansion''': [[Eurocard (printed circuit board)|Eurocard]]-sized [[Podule (expansion card)|Podule]] support in common with Archimedes-series machines. The Risc PC also offers DMA support in the first two podules on the bus. Third parties produced similar cards.
| '''Operating system''': [[RISC OS]], stored in 4&nbsp;MiB ROM (RISC OS 3.50 shipped on 2&nbsp;MiB ROMs) supplemented by disc-based components.
{{unordered list
| Fitted as standard:
{{unordered list
| RISC OS 3.50 (Risc PC 600)
| RISC OS 3.60 (Risc PC 700)
| RISC OS 3.70 (StrongARM Risc PC)
| RISC OS 3.71 (StrongARM Risc PC J233)
| RISC OS 4.03 (Kinetic Risc PC)}}
| RISC OS 4, RISC OS Select, RISC OS Adjust and RISC OS 6 are available from [[RISCOS Ltd]] as a replacement for the Acorn-implemented versions.<ref name=chris-rol>{{cite web|title=Chris's Acorns: RISC OS Ltd|url=http://chrisacorns.computinghistory.org.uk/AfterAcorn/RISCOSLtd.html|publisher=Chris Whytehead|year=2009|access-date=2018-01-26}}</ref>
| RISC OS 5 from [[RISC OS Open]] with the CPU running in 32-bit mode.
| [[Linux]] – no longer supported.<ref name=linux>{{cite web|title=ARM Linux Acorn Overview|url=http://www.arm.linux.org.uk/machines/riscpc/|publisher=ARMLinux|year=2009|access-date=13 August 2009}}</ref>
| [[NetBSD]]<ref name=netbsd>{{cite web|title=NetBSD/acorn32|url=http://www.netbsd.org/ports/acorn32|publisher=NetBSD|year=2009|access-date=13 August 2009}}</ref>}}
| '''Case''': Designed by industrial designer [[Allen Boothroyd]]<ref name="pcw burley 199406">{{cite news | url=http://chrisacorns.computinghistory.org.uk/docs/Mags/PCW/PCW_Jun94_RPC600.pdf | title=Acorn RISC PC 600 | work=[[Personal Computer World]] | date=June 1994 | access-date=30 August 2013 | author=Burley, Ian}}</ref> of Cambridge Product Design (designer of the BBC Micro case). Custom plastic-based design with a 'slice' feature which allows extra case modules to be added to increase internal expansion space. Each slice adds two podule bays at the rear, and two [[drive bay]]s (one 3.5-inch, one 5.25-inch) at the front, covered by a retractable flap to hide cosmetic inconsistencies in hue. Some slices were internally sprayed with nickel paint to meet electromagnetic and radio emissions regulations.
| '''CD-ROM drive''': Optional extra, offering limited compatibility with [[multimedia]] PC [[CD-ROM]]s.<ref name="tes misguided loyalties">{{cite news | url=http://www.tes.co.uk/article.aspx?storycode=94608 | title=Trading on misguided loyalties? | work=[[Times Educational Supplement]] | date=20 October 1995 | access-date=10 November 2011 | author=Lambert, Andy | quote=Acorn has been pressed to give its users access to Windows Multimedia PC CDs ... there are still doubts about full compatibility.}}</ref>
| '''Ports''': [[RS-232]] serial, parallel, [[PS/2 port|PS/2]] keyboard, Acorn mouse, headphone audio out, [[D-subminiature|DE15]] [[Video Graphics Array|VGA]], network (optional).
| '''Additional configurations''':
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| Hydra multi-processor development system from Simtec. This plugged into the front processor slot and propagated the two original slots from the standard Risc PC, adding five extra slots, four being used by processor cards (these being the existing ARM610 or ARM710 cards at that time) with one slot accepting a static RAM card acting as a cache or shared memory. The Hydra card provided arbitration logic to manage the multiprocessor functionality, avoiding the need for each processor card to have such logic (as was the case with the 486 processor card which had an ASIC for this purpose), thus providing the hardware basis of a multiprocessing solution for the Risc PC. Simtec were considering Taos and Helios as potential operating systems to make use of the card.<ref name="acornuser199512">{{ cite news | url=https://archive.org/details/AcornUser162-Dec95/page/n8/mode/1up | title=Simtec multi-processor board arrives | work=Acorn User | date=December 1995 | access-date=1 April 2021 | pages=9 }}</ref> }}
| '''Dimensions''': 117 (182 for two centre-sections) × 355 × 384&nbsp;mm (H×W×D).}}