MK Slotexpander V3.0
This page was last modified 20:25, 13 March 2018 by Grauw. Based on work by Lynn and Mars2000you and others.


The slotexpander expands your slot into 4 subslots. These are numbered from 1 to 4. The one which is closest to the switches (this is the front) is number 1, the one on the other side is 4. The ones between are 2 and 3.

Although the subslots are numbered from 1 to 4 on the expander, the computer really sees them as subslots 0 to 3.

Every slot can be turned off. This is done by the dipswitches in the front. To the upside they are on, to the downside off. The I/O ports are still working in the off position.

This slotexpander has support for an external power supply, but no connector is present by default and has to be soldered in by the user.

The hardware design was by Digital KC.


MK Slotexpander 3.0 with PSU
MK Slotexpander 3.0 advertisement

Known issues

  • FM “stereo” PAK: the internal software is not working, unless a RAM cartridge is inserted in the expander.
  • Metal Gear 2 - Solid Snake will only work within a primary slot, but works fine when inserted in subslot 4 of the expander and no RAM cartridge is in the expander.
  • Snatcher Sound Cartridge doesn't work in this slotexpander, probably because of the flatcable length (weaker signal). Use in primary slots instead or confirmed: Snatcher Sound Cartridge does work in Carchano slotexpander (without flatcable) and Modulon (also without flatcable)
  • ESE-SCC cartridge does work in MK slotexpander, but only in subslot 4 and without Sunrise CF-ATA IDE cartridge (use Megaflashrom SCC+ SD for storage instead in primary slot)