Sony HBM-512
This page was last modified 11:48, 8 June 2020 by Gdx. Based on work by Mars2000you and Grauw and others.



The Sony HBM-512 memory mapper is one of the few memory mappers made by an original MSX manufacturer and runs on any MSX2 computer. It was originally designed for the Sony HB-G900P video computer and doesn't work on computers that run on a higher clock frequency than 3.58 MHz, because of the slow RAM chips.


Sony HBM-512 cartridge front
Sony HBM-512 cartridge back
HBM-512 PCB front
HBM-512 PCB back
Sony HBM-512 Manual front
Sony HBM-512 Manual back
Sony HBM-512 box

Minimum System Requirements

  • MSX2 computer, one free slot cartridge

Note: As all standard memory mappers, this cartridge is not supported by MSX1 computers except with Nextor or a MSX-DOS2 unbridled (like Sunrise CF interface). On MSX1 without Nextor, we need to manually initialize the page order of the mapper from basic before it can be used.


  • 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)