Editing Sinclair QL (section)

== Design ==
[[file:Sincalir-QL-68008-Processor.jpg|thumb|Motorola 68008 and ZX8301 on the QL's PCB]]

Based on a Motorola 68008 processor clocked at 7.5&nbsp;MHz, the QL included 128 [[kilobyte|KiB]] of [[random-access memory|RAM]], which is officially expandable to 640&nbsp;KiB and in practice, 896&nbsp;KB.<ref name="Nostalgia Nerd">{{Cite web |last=Leigh |first=Peter |date=2016-03-17 |title=Sinclair QL (Quantum Leap) System Review |url=https://www.nostalgianerd.com/sinclair-ql/ |access-date=2022-11-22 |website=Nostalgia Nerd |language=en-US}}</ref>

It can be connected to a [[Computer monitor|monitor]] or TV for display. Sinclair recommended the "''SINCLAIR VISION-QL''" [[RGB monitor]] for usage with the QL.<ref>{{Cite book |url=https://ia600804.us.archive.org/9/items/SinclairQLHomepage/docs/manuals/visionql.pdf |title=SINCLAIR VISION-QL OWNER'S GUIDE |publisher=MBS Data Efficiency Ltd}}</ref> When connected to a normally-adjusted TV or monitor, the QL's video output [[overscan|overscans]] horizontally. This is reputed to have been due to the timing constants in the ZX8301 chip being optimised for the flat-screen CRT display originally intended for the QL.<ref>{{cite newsgroup |url=http://groups.google.com/group/comp.sys.sinclair/msg/6bdb4bd808bdb3d6 |newsgroup=comp.sys.sinclair |first=Rupert |last=Goodwins |title=Sinclair Loki Superspectrum |message-id=3cde626f.45085128@news-text.blueyonder.co.uk |access-date=2008-04-22}}</ref>

{| class="infobox sidebar"
|+ Sinclair QL color palette
|-
! {{Resx|256x256}}
! {{Resx|512x256}}
|-
| style="color: white; background-color: #000000" | black
| style="color: white; background-color: #000000" rowspan=2 | black
|-
| style="color: white; background-color: #0000ff" | blue
|-
| style="color: white; background-color: #ff0000" | red
| style="color: white; background-color: #ff0000" rowspan=2 | red
|-
| style="background-color: #ff00ff"| magenta
|-
| style="background-color: #00ff00" | green
| style="background-color: #00ff00" rowspan="2"| green
|-
| style="background-color: #00ffff" | cyan
|-
| style="background-color: #ffff00" | yellow
| style="background-color: #ffffff" rowspan=2| white
|-
| style="background-color: #ffffff" | white
|}
Two video modes are available, {{Resx|256x256}} pixels with 8 primary [[RGB color model|RGB]] colours and per-pixel flashing, or {{Resx|512x256}} pixels with four colours: black, red, green and white.<ref name="Nostalgia Nerd" /> Both [[Commodore 64]] and [[MSX]] computers can display more colours, but at lower resolutions.{{r|pountain198409}} Both screen modes use a 32&nbsp;KiB [[framebuffer]] in main memory. The hardware is capable of switching between two different areas of memory for the frame buffer, thus allowing [[Multiple buffering#Double buffering in computer graphics|double buffering]]. However, this would use 64&nbsp;KB of the standard machine's 128&nbsp;KiB of RAM and there is no support for this feature in the QL's original firmware. The alternative and improved operating system [[Minerva (QDOS reimplementation)|Minerva]] provides full support for the second frame buffer. [[file:QL-inside.jpeg|thumb|QL internals (with Minerva ROM fitted)]]Internally, the QL comprises the CPU, two ULAs (ZX8301 "Master Chip" and ZX8302 "Peripheral Chip") and an [[Intel MCS-48|Intel 8049]]<ref name="Nostalgia Nerd" /> [[microcontroller]] known as the IPC, or "Intelligent Peripheral Controller". [[file:Sinclair QL rear view (brighter)(filtered).jpg|thumb|QL rear view]]The ZX8301 implements the video display generator and also provides [[DRAM]] refresh. The ZX8302  interfaces to the [[RS-232]] ports (transmit only), Microdrives, QLAN ports, [[real-time clock]] and the 8049 via a synchronous serial link. The 8049 runs at 11&nbsp;MHz and provides a keyboard/joystick interface, RS-232 serial receivers and an audio generator.<ref name="faq-hardware" /><ref name="Nostalgia Nerd" /> The 8049 was added at a late stage in the QL's design, as the ZX8302 was originally intended to include its functions.<ref name="sunrise" /> 

[[file:Sinclair QL mp3h0654.jpg|thumb|Bundled Psion application software on Microdrive cartridges]]

Two built-in Microdrive tape-loop cartridge drives provide mass storage, in place of the more expensive [[floppy disk]] drives found on similar systems of the era. Microdrives had been introduced for the ZX Spectrum in July 1983, although the QL uses a different logical tape format.

Interfaces include an expansion slot, ROM cartridge socket, dual RS-232 ports, proprietary QLAN [[local area network]] ports, dual [[joystick]] ports and an external Microdrive bus. The QL uses British Telecom type 631W plugs of similar design to [[British telephone sockets]] for serial cables except for QLs built by Samsung for export markets, which have [[D-subminiature|DE-9]] sockets. Joysticks connect to the QL with similar type 630W plugs.

While the keyboard improves on ZX Spectrum's, it is a rubber [[membrane keyboard]] under the keycaps.{{r|pountain198409}} Physically, the QL is the same black colour as the preceding ZX81 and Spectrum, but introduced a new angular styling theme and keyboard design which would later be seen in the ZX Spectrum+.

[[Sinclair QDOS|QDOS]], [[Computer multitasking#Preemptive multitasking|a pre-emptive multitasking]] operating system primarily designed by Tony Tebby, is included on [[read-only memory|ROM]], as is an advanced [[BASIC#Structured BASIC|structured BASIC]] [[Interpreter (computing)|interpreter]], named SuperBASIC designed by [[Jan Jones (novelist)|Jan Jones]], which is also used as the [[Command-line interface#Command-line interpreter|command-line interpreter]].<ref>{{Cite web |title=SBASIC/SuperBASIC Reference Manual Online — SBASIC/SuperBASIC Reference Manual Online 4.0.1 documentation |url=https://superbasic-manual.readthedocs.io/en/latest/ |access-date=2023-04-03 |website=superbasic-manual.readthedocs.io}}</ref> The QL is bundled with an [[Productivity software#Office suite|office suite]], consisting of a [[Word processor program|word processor]], [[spreadsheet]], [[database]], and business graphics written by [[Psion (company)|Psion]].{{r|pountain198409}}

According to Sinclair Research, it was the first mass-market computer with an [[Operating System|OS]] featuring pre-emptive multitasking and a [[Windows]]-style operating system, predating Microsoft [[Windows 95]] by 11 years, and [[Apple Computer]] Macintosh launch by a month.<ref>{{cite web |title=Sinclair QL |url=http://www.sinclairzx.com/about-us.html#15 |archive-url=https://web.archive.org/web/20101220003729/http://www.sinclairzx.com/about-us.html#15 |archive-date=2010-12-20}}</ref>