Category:Toshiba HX-22
This page was last modified 23:46, 12 February 2018 by Rderooy. Based on work by Mars2000you.



The HX-22 is an improved version of the HX-21 computer as it comes with a built-in RS-232C interface with switch. The following models exist:

  • HX-22: model with QWERTY Japanese keyboard
  • HX-22GB: model for Great Britain with QWERTY international keyboard, including a £ key
  • HX-22I: model for Italy with QWERTY international keyboard, including an accents key
Brand Toshiba
Type HX-22 / HX-22GB / HX-22I
Year 1985
RAM 64kB in slot 3-0 (HX-22) or split between slots 0 and 3-0 (checked on HX-22I)
Media MSX cartridges
Video Texas Instruments TMS9928A or TMS9929A
Audio PSG (AY-3-8910A)
Chipset Toshiba TCX-1010 in HX-22, Toshiba TCX-1012 in HX-22I (and probably HX-22GB)
Extras firmware (Japanese Word Processor or English Word Processor), RS-232C interface + switch + RS-232C BASIC, (only Japanese version) MemoryDisk BASIC + Printer BASIC + stereo PSG sound


Check also the pages about the different models!

Toshiba HX-22
Toshiba HX-22 back
Toshiba HX-22 PCB
Toshiba HX-22I
Toshiba HX-22I back
Toshiba HX-22I PCB
Toshiba HX-22GB
Toshiba HX-22GB back


The HX-22 is a MSX1 with 2 cartridge slots (one at the top, one at the back) and a a Z80A from Sharp (LH-0080A).

The 2 joystick ports are located on the right side of the computer, as well as the data recorder connector.

In the HX-22I (and maybe the HX-22GB), the 64kB RAM is split in half between the slots 0 and 3-0, a configuration that can cause poorly written software to crash. Also, with this layout, the POKE-1,(15-PEEK(-1)\16)*17 trick to workaround buggy software that does not handle subslots properly will not work on this machine.


  • RF output
  • RGB output
  • Analog sound (stereo on Japanese version) & Composite video
  • RS-232C connector
  • Tape recorder connector
  • Centronics compatible Parallel port for a printer
  • 2 general connectors (Joysticks, mouse, paddle controllers, ...)
  • 2 cartridge slots

Slot Map on HX22

Slot 0 Slot 1 Slot 2 Slot 3-0 Slot 3-1 Slot 3-2 Slot 3-3
Bank C000h~FFFFh
Slot 1

Slot 2


Bank 8000h~BFFFh
Bank 4000h~7FFFh Main-ROM
Bank 0000h~3FFFh Main-ROM

Slot Map on HX22I

Slot 0 Slot 1 Slot 2 Slot 3-0 Slot 3-1 Slot 3-2 Slot 3-3
Bank C000h~FFFFh RAM
Slot 1

Slot 2

Bank 8000h~BFFFh RAM
Bank 4000h~7FFFh Main-ROM RAM
Bank 0000h~3FFFh Main-ROM RAM

Pages in category "Toshiba HX-22"

The following 3 pages are in this category, out of 3 total.