Hitachi MB-H1
This page was last modified 16:52, 1 June 2022 by Gdx. Based on work by Mars2000you 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 side of the MSX.

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 had split 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

Product Revision Year Price RAM Cursor keys Colour Notes
Hitachi MB-H1 1st 11-1983 ¥62,800 32kB* Not crosswise EA (Elegant Almond) Firmware
Hitachi MB-H1E 1st 02-1984 ¥54,800 16kB* Not crosswise TR (Trad Red) No firmware,
No RF ouput
Hitachi MB-H1 2nd 07-1984 ¥62,800 32kB* Crosswise EA (Elegant Almond)
TR (Trad Red)
Hitachi MB-H1E 2nd 1984 ¥54,800 16kB* Crosswise EA (Elegant Almond)
TR (Trad Red)
No firmware,
No RF ouput

(*) 64kB could be added internally on demand to the purchase (Business version)


Brand Hitachi
Model MB-H1
Year December 1983
Region Japan
Launch price see table above
RAM 16KB (MB-H1E) or 32KB (MB-H1) in slot 0
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, firmware (only MB-H1): 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).

The firmware is not available on the MB-H1E.




Hitachi MB-H1 manual
Hitachi MB-H1 (EA) 1st rev with PSU
Hitachi MB-H1 (EA) 2nd rev
Hitachi MB-H1 (EA) 1st rev left side
Hitachi MB-H1 (EA) 1st rev right side
Hitachi MB-H1 (EA) 1st rev PCB
Hitachi MB-H1 (EA) 1st rev box
Hitachi MB-H1 (TR) 2nd rev box
Hitachi MB-H1 (TR) 2nd rev
Hitachi MB-H1 (TR) 2nd rev inside
Hitachi MB-H1 (TR) 2nd rev with PSU
Hitachi MB-H1 Power supply
Hitachi MB-H1 PSU connection
Hitachi 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
Hitachi MB-H1 (EA) 1st rev left side


Hitachi MB-H1E 2nd rev left side
Hitachi MB-H1E 2nd rev
Hitachi MB-H1E 2nd rev label
Hitachi MB-H1E 2nd rev back
Hitachi MB-H1E 2nd rev right 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 not working 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 of model MB-H1

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

Slot Map of model MB-H1E

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
Page 0000h~3FFFh



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. 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