Editing Acorn Electron (section)

===Second Processor expansions===
Acorn did demonstrate a prototype "Tube" interface for the Electron alongside the Plus 3 interface at the Compec exhibition in November 1984,<ref name="elbug198501">{{ cite news | url=https://archive.org/details/elbug-magazine-1985-01/page/n23/mode/1up | title=Acorn Bits | work=ELBUG | date=January 1985 | access-date=28 December 2020 | page=24 }}</ref> although this was never brought to market directly by Acorn.

====Advanced Plus 5====
Despite Acorn's withdrawal from the Electron peripheral market, Baildon Electronics developed the Advanced Plus 5 (AP5) expansion,<ref name="ap5">{{ cite web | url=http://www.acornelectron.co.uk/info/electron/acp_pres/Advanced-Plus-5.html | title=Advanced Plus 5 | website=Acorn Electron World | access-date=28 December 2020 }}</ref> featuring Tube, 1&nbsp;MHz bus and user port interfaces, which plugged into a Plus 1 cartridge socket. This provided a sufficient level of compatibility that both the 6502 and [[Zilog Z80|Z80]] second processor products from Acorn were shown to work, providing a Tube implementation that was "as faithful as you can get", with it also being noted that the Electron being available for as little as £50 at that point in its commercial lifespan was a "very cheap way of getting a [[CP/M]] machine".<ref name="abcomputing198708">{{ cite news | url=https://archive.org/details/AB_Computing_1987-08_OCR/page/n67/mode/2up | title=Electron Plus 5 | work=A&B Computing | date=August 1987 | access-date=28 December 2020 | last1=Grace | first1=Clive | pages=68–70 }}</ref> Some differences in the memory map of the Electron meant that BBC Micro software would need modifications to work on the Electron with AP5. The price of the unit in late 1986 was £66.70.<ref name="electronuser198612">{{ cite magazine | url=https://archive.org/details/ElectronUserVolume4/Electron-User-04-03/page/n66/mode/1up | title=Any port in a storm | magazine=Electron User | volume=4 | issue=3 | last1=Cook | first1=Mike | date=December 1986 | access-date=19 January 2021 | pages=67–68 }}</ref>

The additional facilities of the AP5 alongside the Tube interface permitted various expansions for the BBC Micro to be made available for the Electron. These included the Hybrid Music 5000<ref name="electronuser198810" /> and the AMX Mouse.<ref name="electronuser198612amx">{{ cite magazine | url=https://archive.org/details/ElectronUserVolume4/Electron-User-04-03/page/n4/mode/1up | title=Now Electron can have its own mouse | magazine=Electron User | volume=4 | issue=3 | date=December 1986 | access-date=21 January 2021 | page=5 }}</ref>

====PMS Electron Second Processor====
In 1986, Permanent Memory Systems (PMS) announced a second processor product for the Electron, the PMS-E2P, as a self-contained cartridge for use with the Plus 1 containing a second 2&nbsp;MHz 6502A processor plus 64&nbsp;KB of RAM, priced at £89.<ref name="electronuser198607a">{{ cite magazine | url=https://archive.org/details/ElectronUserVolume3/Electron-User-03-10/page/n5/mode/1up | title=More speed, memory | magazine=Electron User | volume=3 | issue=10 | date=July 1986 | access-date=17 January 2021 | page=6 }}</ref> This was based on a product originally developed by John Wike of Jafa Systems.<ref name="electronuser198907" /> Available as a kit or in assembled form, it could even be adapted to connect directly to the Electron's expansion connector, thus avoiding the need to even have a Plus 1 expansion, although this would require the user to find other solutions for attaching peripherals. The implementation of the interface between the Electron and second processor was said to adhere closely to Acorn's recommendations, noting that any hardware or software compatibility issues were likely to be the fault of other vendors not similarly adhering to Acorn's guidelines.<ref>{{cite news | url=http://www.acornelectron.co.uk/mags/aab/revs/pms/r-e2p.html | title=Electron GTS | work=A&B Computing | date=April 1986 | volume=3 | issue=3 | last1=Grace | first1=Clive | archive-url=https://web.archive.org/web/20180708133459/http://www.acornelectron.co.uk/mags/aab/revs/pms/r-e2p.html |archive-date=8 July 2018}}</ref> PMS supplied Acorn's Hi-BASIC with the E2P, permitting the use of as much as 44&nbsp;KB of the second processor's RAM with BASIC programs.<ref name="electronuser198610_e2p">{{ cite magazine | url=https://archive.org/details/ElectronUserVolume4/Electron-User-04-01/page/n54/mode/1up | title=High speed – and memory to match | magazine=Electron User | last1=Waddilove | first1=Roland | date=October 1986 | access-date=9 June 2023 | pages=55–56 }}</ref> The company also made a version of Computer Concepts' Wordwise Plus available for the E2P, priced at £39.95.<ref name="electronuser198703_wordwiseplus">{{ cite magazine | url=https://archive.org/details/ElectronUserVolume4/Electron-User-04-06/page/n9/mode/2up | title=Wordwise Plus | magazine=Electron User | last1=Turnbull | first1=Steve | date=March 1987 | access-date=9 June 2023 | pages=10–12 }}</ref>