Hitachi MB-H21

I have the main unit (CIB).

type computer
country Japan
year 1984
os Microsoft Extended Basic (MSX Basic 1.0)
cpu Zilog Z80A
speed 3.6 MHz
ram 32 KB
rom 32 KB
graphic 256×192
colors 16
sound 3 channels, 8 octaves
ports 2 x cartridge slots, tape, 2 x joystick, rf, video/audio out

---

The Hitachi MB-H21 — Hitachi’s MSX Computer

The Hitachi MB-H21 was a first-generation MSX home computer produced by Hitachi Ltd — one of Japan’s largest and most diversified electronics conglomerates — as part of the broad MSX ecosystem that united Japanese manufacturers behind a common standard in 1983 and 1984. Hitachi’s participation in the MSX initiative reflected the standard’s importance in Japan, where it was backed by Microsoft, ASCII Corporation, and the major Japanese consumer electronics companies as a unified home computer platform.

Hitachi’s Technology Pedigree

Hitachi Ltd, founded in 1910, was one of Japan’s most important industrial conglomerates — producing everything from power generation equipment and railway systems to consumer electronics and semiconductors. In the computing field, Hitachi had produced mainframe computers, minicomputers, and industrial systems long before the home computer era. The MB-H21 represented Hitachi’s participation in the consumer end of the computing market — using the MSX standard to offer a competitive product without the expense of developing a proprietary architecture.

MSX Compliance

As a first-generation MSX machine, the MB-H21 used the standard MSX hardware specification: a Zilog Z80 compatible processor at 3.58 MHz, a Texas Instruments TMS9918 video processor providing 256×192 pixel graphics with 16 colours and 32 hardware sprites, a General Instrument AY-3-8910 three-voice sound chip, and MSX BASIC 1.0 in ROM. This standardisation ensured complete software compatibility with all other MSX machines — the central promise of the MSX standard and the key to its commercial viability.

Japanese Home Computing

The MSX standard achieved its greatest success in Japan, where it became the dominant home computer platform of the mid-to-late 1980s, supported by major software publishers including Konami, which developed many of its most celebrated game series — including early Metal Gear and Castlevania titles — for the MSX platform. Hitachi’s MB-H21 was one of many MSX machines available in Japanese electronics stores, competing primarily on price, build quality, and any distinctive features beyond the standard specification.