Editing Acorn Electron (section)

===Slogger/Elektuur Turbo boards===
Announced in early 1986, the Slogger Turbo-Driver was a professionally fitted upgrade priced at £42.<ref name="electronuser198602">{{ cite magazine | url=https://archive.org/details/ElectronUserVolume3/Electron-User-03-05/page/n8/mode/1up | title=Upgrade 'boosts Electron's speed 100 per cent' | magazine=Electron User | volume=3 | issue=5 | date=February 1986 | access-date=15 January 2021 | page=9 }}</ref> The board itself plugged into the CPU and BASIC ROM sockets on the main circuit board of the Electron, which merely involved removing socketed components on very early Electron models, but required desoldering work and therefore benefited from a fitting service for later units. The performance benefit of fitting the board was to make some programs, particularly those running in the high bandwidth modes (0 to 3), run up to three times faster.<ref name="electronuser198607t">{{ cite magazine | url=https://archive.org/details/ElectronUserVolume3/Electron-User-03-10/page/n21/mode/2up | title=Putting Electron into turbo-drive | magazine=Electron User | volume=3 | issue=10 | date=July 1986 | access-date=17 January 2021 | last1=Waddilove | first1=Roland | pages=22–23 }}</ref>

The direct origins of the Slogger product appear to be a board designed by Andyk Limited,<ref name="electronuser198607s">{{ cite magazine | url=https://archive.org/details/ElectronUserVolume3/Electron-User-03-10/page/n23/mode/2up | title=The Elk Turbo-Driver | magazine=Electron User | volume=3 | issue=10 | date=July 1986 | access-date=17 January 2021 | page=24 }}</ref> announced as the Fast Electron Board in late 1985 with a price of £29.99,<ref name="electronuser198512">{{ cite magazine | url=https://archive.org/details/ElectronUserVolume3/Electron-User-03-03/page/n8/mode/1up | title=New board gives Electron speed of BBC Micro | magazine=Electron User | volume=3 | issue=3 | date=December 1985 | access-date=17 January 2021 | page=9 }}</ref> whereas the Elektuur modification was described in an article in Dutch Electronics magazine Elektuur and intended for users to perform at home.<ref name="8bs">{{cite web|url=http://www.8bs.com/see/kupers_electron_6.jpg |title= kupers_electron_6 |publisher=8bs.com|access-date=17 September 2015}}</ref>

The Slogger and Elektuur Turbo boards were born out of a hack initially devised at Acorn. By shadowing the lowest 8&nbsp;KB of RAM with a static RAM chip outside of reach of the ULA, the CPU could always access it at 2&nbsp;MHz. The tradeoff was that the screen could not be located in that 8&nbsp;KB. In practice the operating system ROMs always put the screen into the top 20&nbsp;KB and as a result this probably only broke compatibility with around 2% of software.{{Citation needed|date=October 2021|reason=It would be nice to see the source giving Acorn as the origin of this design, also of the incompatibility figure which sounds like it originates in an article.}} Speeding up the low portion of memory is particularly useful on [[MOS 6502|6502]] derived machines because that processor has a faster [[zero page|addressing for the first 256 bytes]] and so it is common for software to put any variables involved in time-critical sections of program into that region.

The cost of the 64 Kbit [[Static random-access memory|SRAM]] chip would have been more than that of doubling the four 64 Kbit DRAM chips to give 8-bit RAM access,{{Citation needed|reason=Reliable pricing information from the time would be highly informative, not just to substantiate this statement but also when assessing the machine's design choices generally. |date=April 2020}} fixing both the modest memory and poor performance issues of the Electron.