Category:Toshiba HX-20
This page was last modified 09:58, 13 January 2018 by Rderooy. Based on work by Mars2000you.



The HX-20 is the first computer released by Toshiba in his second serie of MSX computers. Contrary to its follower, the HX-21, this machine is without a RGB output connector. The following models exist:

  • HX-20: model with QWERTY Japanese keyboard
  • HX-20AR: model for Argentina with QWERTY international keyboard, including an accents key
  • HX-20E: model for Great Britain with QWERTY international keyboard, including a £ key (but some pictures on the net show a HX-20E box containing a computer with the same keyboard as HX-20AR and HX-20I)
  • HX-20I: model for Italy with QWERTY international keyboard, including an accents key

Although it's a MSX1 computer, it can use a part of the MSX memory to create a RAM-Disk or Memory Disk (feature generally reserved for computers with version 2.1 of MSX-BASIC).

Brand Toshiba
Type HX-20 / HX-20AR / HX-20E / HX-20I
Year 1984 in Japan - 1985 in Europe - 1986 in Argentina
RAM 64kB split between slots 0 and 3-0
Media MSX cartridges
Video TMS9128 (HX-20AR) or Toshiba T6950 (other models)
Audio PSG (AY-3-8910A)
Chipset Toshiba TCX-1010 or Toshiba TCX-1012
Extras firmware (Japanese Word Processor or English Word Processor), MemoryDisk BASIC, (only Japanese version) Printer BASIC and stereo PSG sound, (only Japanese version and optional) RS-232C interface + switch + RS-232C BASIC


Check also the pages about the different models!

Toshiba HX-20
Toshiba HX-20 back
Toshiba HX-20AR
Toshiba HX-20I
Toshiba HX-20I back
Toshiba HX-20I right side
Toshiba HX-20AR inside


The HX-20 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.

The used VDP is most versions of this computer is the Toshiba T6950, which does not support some undocumented features of the Texas Instruments TMS9918, TMS9928 and TMS9929 VDP's.

The 64kB RAM is split between 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
  • Analog sound (stereo on Japanese version) & Composite video
  • (only Japanese version and optional) RS-232C connector
  • Tape recorder connector
  • Centronics compatible Parallel port for a printer
  • 2 general connectors (Joysticks, mouse, paddle controllers, ...)
  • 2 cartridge slots

Pages in category "Toshiba HX-20"

The following 4 pages are in this category, out of 4 total.