Hitachi MB-H1
This page was last modified 01:19, 11 August 2023 by Mars2000you. Based on work by Gdx and Rderooy.
Hitachi MB-H1 rev.2 (TR)




The Hitachi MB-H1 was aimed at the Japanese market. This model was released in two colors, "Elegant Almond" (EA) at first then also "Trad Red" (TR). It has a CPU speed controller switch on the right side, allowing slow games execution.

The main unit is equipped with a pull-out handle under the keyboard, and the power supply can be attached to the main unit for transport.

It was marketed as being easy to take with you having about an A4 size. In marketing literature they would show it being carried, typically by a school child or in a briefcase without the power supply, which can give you the impression the large power brick is optional, which it is not. The power supply is quite heavy.

The computer can be used with power supply attached to the unit, but you can not access the printer, analog sound or composite video ports as well. The power connection from the power supply to the MSX is via a cable which plugs into the left side of the computer.

A second revision of the HB-1 was released with the cursor keys arranged as on the majority of MSXs instead of the horizontal keys above the vertical ones.

There is a small place above the function keys to put a label to indicate their function.

Hitachi also released a downgraded version, see MB-H1E. Manual and box are the same for MB-H1 and MB-H1E.

The production was split for each version into two lines, one for the home which was commercially available, the other for business with 64KB extra RAM that was available on demand only.

There were also plans for an European version with more RAM, but it has never been released - see MB-H80.

Known variations

Revision Year Cursor keys Color
1st 11-1983 Not crosswise EA (Elegant Almond)
2nd 07-1984 Crosswise EA (Elegant Almond)
TR (Trad Red)


Brand Hitachi
Model MB-H1
Year December 1983
Region Japan
Launch price ¥62,800
RAM 32KB in slot 0
64kB could be added internally on demand to the purchase (Business version)
Media MSX cartridges
Video Texas Instruments TMS9918ANL
Audio PSG (AY-3-8910)
Chipset none (separate IC's)
Keyboard layout QWERTY/JP50on
Extras CPU speed controller switch, pull-out handle, firmware: System monitor utility, Explanation to use cartridges, Sketch Program, Sound Play
Emulation ROMs dumped and emulated


When the menu is displayed, press a function key from F1 to F5:

  • F1 - MSX-BASIC
  • F2 - MB-H1 System Monitor Utility (Machine code disassembler/monitor)
  • F3 - ROM cartridges usage (Explanation to use cartridges)
  • F4 - Sketch Program (a simple drawing program)
  • F5 - Sound Play (Music keyboard)

There is no any key to bypass the firmware menu when booting because it is auto-bypassed when a ROM cartridge is inserted.

If you stay on the menu, an automatic demo of the 3 last options will begin after a bit.

When you have started an application, you can go back to the menu by entering E in the monitor or by pressing STOP in the other applications.

From MSX-BASIC, you can launch the command line of the Monitor with CALL MON or _MON (to get the list of all available commands in this utility, enter H on the command line - back to BASIC by entering E).



Hitachi MB-H1 manual
MB-H1 (EA) 1st rev with PSU
Hitachi MB-H1 (EA) 2nd rev
MB-H1 (EA) 1st rev left side
MB-H1 (EA) 1st rev right side
Hitachi MB-H1 (EA) 1st rev PCB
MB-H1 (EA) 1st rev box
MB-H1 (TR) 2nd rev box
Hitachi MB-H1 (TR) 2nd rev
MB-H1 (TR) 2nd rev inside
MB-H1 (TR) 2nd rev + PSU
Hitachi MB-H1 Power supply
Hitachi MB-H1 PSU connection
MB-H1 (TR) 2nd rev packaging + Hobby PC Guide Book
Hitachi MB-H1 (EA) label
Hitachi MB-H1 (EA) 2nd rev back
Hitachi MB-H1 2nd rev RF PCB
MB-H1 (EA) 1st rev left side


Hitachi MB-H1 firmware Menu
MB-H1 Monitor Utility
ROM cartridges usage
Sketch Program (intro)
Sketch Program
Sound Play


The MB-H1 is a MSX1 with a CPU speed controller for slow games execution. The CPU is a Z80A from Sharp (LH0080A).

The firmware is auto-bypassed when a cartridge is inserted in the slot 1 or 2 but it does not work with a slot expander. To remedy this drawback, you have to insert a ROM cartridge in one of the two primary slots or dessolder the HN61364P ROM (IC34) which contains the firmware. This one is virtually useless but if you prefer to keep it, you can replace the original firmware by this patched version.

Pins -12V and +12V of the cartridge connectors are not connected.

Slot Map

Slot 0 Slot 1 Slot 2 Slot 3
Page C000h~FFFFh RAM Cartridge
Slot 1
Slot 2
Page 8000h~BFFFh
Page 4000h~7FFFh Main-ROM Firmware
Page 0000h~3FFFh
  • The firmware application is 8kB from 4000-5FFF



The MB-H1 RAM of the second revision can be upgraded by adding the missing components on the board with the RF output and connect the board to the two connector near cartridge slots. The firmware ROM probably needs to be removed to make the upgrade. The extra RAM is on a separate board for the MB-H1 of the first revision. (Please help us to find more info about it.)

External links