MSX -  Sony HB G900P

Sony HitBit F900P MSX2 with Genlock

The HB-G900P is a 1985 Sony MSX2 personal computer system which focused on the business and professional markets. The computer features a Genlock and superimpose function for external video and can be used together with the SOny Lasermax LaserVision LDP-1500P Video Disc Player.

The computer has a built-in floppy drive, two cartridge slots one at the front and rear. The separate keyboard is also equipped with a numeric keypad and cursor keys. The HG-900P is equipped with a Genlock module to combine images from the MSX2 VDP and an external video input. The MSX2 BASIC has been expanded with a extra instructions for controlling the laser disc player and the GenLock module.

The MSX2 Standard

The MSX2 Standard was introduced as successor to the MSX standard. The biggest improvement on the standard were the video capabilities of the system. Where the MSX-1 was quite capable with 16 colors and hardware sprites, it had some limitations. The graphics mode was pattern based, which meant that pixels were grouped by the 8, and each 8 pixels could only have one foreground and one background color. For games and pictures this meant that there was a color spill effect, colors bleeding over in unwanted areas.

The MSX2 introduced a new Video Display Processor, the V9938. This chip had the capacity to display 256 color simultanously, or have graphics modes with 16 colors out of a 512 color palette. It had true bitmapped graphics, that offered multiple in-memory pages for double buffering or vertical scrolling. The sprite system now supported multi-color sprites, and up to 8 sprites per scan-line. The Video RAM was defined to be at least 64KByte, but most systems came with 128KByte which was the maximum the V9938 supported.

The V9938 made it possible to create some great games. The most famous is the very first version of Konami's excellent game Metal Gear.

MSX I/O Ports

The follwing sections details the Standard MSX I/O ports that are available on every MSX.

    MSX Cassette Pin Layout

  • The MSX Standard calls for all MSX computers to have a standard data-cassette port. This port transports the audio-in/out signals to and from the datarecorder and the computer has a relay-switch on board to turn the recorder on and off.

  • MSX Cartridge Connector

  • The MSX Cartridge system uses a 50-pin flat-edge connector to connect to the systems expansion bus. The cartridge slot maps into one of the main- or sub-slots.

  • MSX Joystick Connector

By Sony CPU Zilog Z80A @3.58MHz Memory 128K RAM, 128K VRAM Sound 3 wave channels + white noise Sprites 16 color, 16x16, 8/scanline, 64 total Display 512x212 16 of 512 RGB, 256x212 256 colors, GEN-Lock Display Chip Yamaha V9938 VDP Sound Chip Yamaha YM2149F Programmable Sound Generator CPU Class Z80 Developed by Sony
Related Systems
Sony HB  G900P
MSX 2+
MSX Turbo-R
Books & Publications
Books related to the MSX Standard of microcomputers
Magazines & Serials
MSX Computer Club Magazine - MSX Blad van MSX Club Belgie/Nederland
MSX Computer Magazine - Maandblad voor MSX-Gebruikers
MSX Magazine from Brazil, later included Amiga as well
MSX Fan, Japanese MSX Magazine
Magazine voor MSX gebruiker en programmeur
Het Nederlandstalige computerblad voor MSX-Bezitters
MSX Magazine, Japanese MSX Magazine
MSX Micro Magazine, Brazilian MSX magazine
MSX Mozaïk was a user group magazine started by Dirk Scheper. The magazine first appeared as a single page in the MSX-Info magazine of January 1985.
MSX World, spanish MSX Magazine
World Wide Web Links
MSX Resource Center dedicated to MSX. It has an extensive archive of MSX news, an active MSX forum, lots of information in their MSX wiki and a large section of free MSX software.
MSXVR is a computer that is hardware and software compatible with MSX computers, implemented in FPGA.
Computer fandom website for MSX