ElkSD Plus 1 Acorn Electron SD Card Interface
Cartridge and 48K RAM Expansion (Rev 1.x)

ElkSD Plus 1 Features

  • Uses standard SD cards, up to 8GB in capacity
  • Inserts into a cartridge slot on the Plus 1 expansion
  • Expands the Electron to 48K of RAM
  • Excellent compatibility with games (PAGE=&E00)
  • Uses widely available .SSD disk image files
  • Free sidways RAM page can be used to load ROM images
  • LOAD and SAVE your own programs
  • Uses the popular MMFS filesystem
  • Requires an Acorn Plus 1 expansion unit

About the ElkSD Plus 1 Rev 1.x

The ElkSD64 has proved to be extremely popular, but people regularly asked if there was a version that would work with the Plus 1 expansion. Those requests lead directly to the ElkSD Plus 1.

The ElkSD-Plus 1 is a combined SD card interface and RAM expansion in cartridge form, which works in a Plus 1 cartridge slot. 

The ElkSD-Plus 1 is cable of using two seperate versions of the MMFS filesystem, switchable either by jumper or in software. By default MMFS 1.4x is used, ensuring maximum compatibility and stability. But MMFS 2 is also available, which some people will prefer as it enables easier use of .SSD images but at the cost of breaking compatibility with game launcher menus. 

Another new feature is the failed flash recovery system. If a problem occurs when updating the ElkSD-Plus 1's software setting a jumper will enable the cartridge to boot from a backup copy of MMFS and be able to re-run the update flashing process.

The Plus 1 cartridge slots are limited to two 16K memory banks per cart, as one bank is used by the MMFS ROM this means the 32K of RAM on the ElkSD64 has had to be reduced to 16K on the ElkSD Plus 1, resulting in a total of 48K usable RAM on the Electron.

Buying an ElkSD Plus1

The ElkSD Plus 1 rev 1.x is no longer available, it has been replaced by the rev 2.x version.


Installation Instructions elksdp1_inst.pdf Installation Instructions (2.x)
User Guide ESDP1_Guide.zip ElkSD-Plus 1 full user guide.
Games Collection (Big) elkbig.zip A large third-party collection of Electron games, some need sideways ram to run.

Please note: these downloads are for revision 2 ElkSD Plus 1 cartridges only. If you don't know which revision you have, check the side of the cartridge. The rev 1 has a 3-pin jumper block on the side, the rev 2 does not.