AX architecture. AX (Architecture eXtended) was a Japanese computing initiative starting in around 1986 to allow PCs to handle double-byte (DBCS) Japanese text via special hardware chips, whilst allowing compatibility with software written for foreign IBM PCs.

History 
The idea was conceived by Kazuhiko Nishi before he resigned his position as vice president of Microsoft. Microsoft Japan took over the project, and in July 1987 the Preparatory Committee of the AX Consortium started developing its specification. 

The AX Consortium officially started in October 1987, including ASCII Corporation, Sony, Hitachi, Sharp, Oki, Casio, Canon, Kyocera, Sanyo, Mitsubishi Electric, etc., but notably excluding Toshiba and Fujitsu (who were hence the 'opposition'). 

At that time, NEC PC-9801 was the dominant PC architecture in the Japanese PC market because IBM PC/AT and its clone PCs could not display Japanese text. However, NEC did not tolerate PC-9801 compatible machines and was fighting court battles with Epson which was the only PC-9801 compatible machine vendor. Therefore, other vendors desperately needed a standard specification for Japanese capable PCs.

Eventually two standards were developed: JEGA and AX-VGA.

Due to less available software and its higher cost compared to the PC-9801 series, AX failed and was not able to break into the market in Japan. The Nikkei Personal Computing journal reported in 1989 that only 18 out of 36,165 PCs used in 937 companies were AX machines, and 90% of companies had no plan to purchase the AX machine.

In 1990, IBM Japan unveiled DOS/V which enabled IBM PC/AT and its clones to display Japanese text without any additional hardware using a standard VGA card. Soon after, AX disappeared and the decline of NEC PC-9801 began.

AX architecture machines 
Several companies released AX computers:

 Oki Electric Industry if386AX30 / 50 series
 Casio Computer AX-8000D / 8000L
 Canon Axi DX-20 / 20P / 10 / 10P
 Kyocera AX386 model A
 Sanyo Electric MCB-17 /18  series 
 Sharp AX286D / 286L / AX386 ( MZ-8000 )
 Sony Quarter L (PCX-300 series)
 Acer ACER1100 / 1200 / 1170
 NCR PC-AXL / PC-AX32
 Hitachi FLORA 3010 / 3020 series
 Mitsubishi Electric  MAXY (M3201 / M3202 / M3205)
 Yokogawa-Hewlett-Packard Vectra-AX series

JEGA 
To display Kanji characters with sufficient clarity, AX machines had  screens with a resolution of  rather than the  standard EGA resolution prevalent elsewhere at the time. JEGA was developed jointly by ASCII and Chips & Technologies, combining the P82C435 and V6367 video chips. Users could typically switch between Japanese and English modes by typing JP and US, which would also invoke the AX-BIOS and an IME enabling the input of Japanese characters.

In addition to the modes provided by EGA, JEGA supports the following display modes as standard:

  character text display, effective resolution  pixels, 8 pages: overwrites modes 2h (graphic screen and overlaid display) and 3h of EGA;
  pixels graphics: 1 page or 1 page overlaid with text screen.

AX-VGA 
IBM released the VGA standard soon after AX was introduced. Since the AX architecture was not compatible with the new standard, the AX consortium had to design a VGA compatible chipset . 

This was called  and could be implemented in two ways: 

 AX-VGA/H, a hardware implementation based on the AX-BIOS; 
 AX-VGA/S, a software emulation. 

Development of the AX-VGA chipset was delayed, and its first implementation came out in 1991. By that time, DOS/V was already available, allowing standard IBM PC compatibles to display Japanese text using a VGA card. The need for AX was gone and further developments were discontinued.

See also
DOS
DOS/V
Shift JIS
PC Open Architecture Developers' Group (OADG)

References

Further reading

External links
 Mitsubishi Maxy (information from a Japanese computer museum)
 Oki if386AX (information from a Japanese computer museum)

Graphics hardware
Computer-related introductions in 1986