This page was last modified 04:12, 10 August 2022 by Mars2000you. Based on work by Gdx and PAC.



The LPE-4FMB-V8SKP is 4MB RAM memory expansion with MegaRam modes.

This expansion seems the same as the LPE-4MB-V4SKP but programmed to support a extra MegaRam mode.

Cartridge contacts are gold plated.

Price: 85€.


LPE-4FMB-V8SKP operating diagram


  • 4096kB DRAM chips configurable as Memory Mapper or MegaRAM (Konami4, Konami5, ASCII8 and ASCII16 compatible).
  • Up to 14.3MHz.
  • Mapper registers readable and auto-updated at MSX reset (FFh=0, FEh=1, FDh=2, FCh=3)
  • MSX1/MSX2/MSX2+/MSX Turbo R compatible.
  • Panasonic A1-WX/A1-WSX 5.37MHz turbo mode non-compatible.
  • PCB compatible with Sony, Konami and MSX Cartridge Shop cartridge cases.

The upper 2048kB RAM are used for the MegaRAM mode. The mode selection register is accessible via the I/O port 54h. Set the bit 0 to enabled the MegaRAM mode. The bit 1 allows you to setect the mapper pages size (0/1 = 16K/8K).

Then, the most signifiant bytes of the switching addresses must be defined via the I/O ports 55h to 58h for the 8K mapper, or 5Ah and 5Bh for the 16K mapper.

For example, OUT &H54,&H80: OUT &H5A,&H60: OUT &H5A,&H70 define the ASCII 16K mapper.

The Rom mapper will be enabled after an MSX reset.

Minimum System Requirements

  • MSX1 computer, one free slot cartridge


  • LPE4FMB.COM - Included Rom loader v1.6 (Rename the file LPE4FMB.COM)
  • LPE4FMB2.COM - Included Rom loader v1.8 (Rename the file LPE4FMB2.COM)
  • BMMS (Bigger Memory Mapper Selector)
  • CHKMEM.BIN (Utility that displays the slot of RAM, Memory Mapper and MegaRAM by LARK)
  • Mapper Info (by Yukke)
  • MEGA16.COM (loader for megaroms with 16k mapper)
  • MEMTEST.COM (RAM of Memory Mapper tester by Masatoshi Fujimoto)
  • TESTMAP.COM (RAM of Memory Mapper tester by Marteen)
  • SofaRom (MegaRoms and Roms loader by Louthrax)