This page was last modified 21:33, 8 March 2018 by Sylvester. Based on work by Mars2000you and Grauw and others.

GR8NET is a combo cartridge for MSX with Network as its main function. It has 7 distinctive mapper modes (GR8NET, plain ROM, Konami/SCC, ASCII8/16, 1024kB mapped RAM) and one combined mapper mode 8 with network, 512kB mapped RAM, Nextor SD-card interface and OPLL ROM available.

It also has, since serial number 6C, a native stereo out. You can also use a switch to let only the PSG signal go out of the MSX audio out and the other sound expansions through the native stereo ouput of the Gr8NET.

The cartridge operates in primary slot (all mapper modes) and sub-slot (except mode 8 when slot expansion is performed internally), in all MSX models.

GR8NET developer, Eugeny Brychkov, is a developer of platform called GR8BIT.


  • RJ-45 UTP Ethernet connection, 10/100 Mbit auto-negotiation / auto MDI, IPv4
  • TCP, UDP, RAW and HTTP communication protocols
  • Built-in simple web browser to browse web server directory tree
  • DHCP configuration, DNS auto-resolution
  • 2 user programmable sockets
  • MSX-BASIC extended command support
  • Built-in telnet application
  • Built-in HTTP-based bload application
  • Operation as 1 Megabyte mapped RAM
  • ROM mapper emulation (plain, Konami)
  • Built-in SCC/SCC+ for standalone and Konami implementations
  • Hardware accelerated functions:
    • Interrupt generator using time period or frequency, with watchdog
    • PCM buffered 8- and 16-bit mono performance
    • Data prefetch from onboard RAM, ROM and W5100
    • Micro-SD card interface
    • Mathpack for FAT16/FAT32 and 32-bit multiplication and division
  • Native stereo output since serial number 6C
  • Mixed GR8NET mapper 512K, Mapped RAM 512K mode plus Nextor with SDC support
  • RAM-disk 2KB to 720KB, user programmable size
  • Operates at standard 3.58 MHz as well as at overclocked 7.11 MHz bus speeds
  • Built-in OPLL (YM2413, MSX-MUSIC) with its ROM BIOS (in mapper mode 8)
  • Built-in OPL-1 with ADPCM (Y8950, MSX-AUDIO)
  • MP3 audio streaming from network and SD-card
  • TCP/IP UNAPI version 1.0 implementation