ECMA-23



ECMA-23 is a standard for a bit-paired keyboard layout adopted in 1969 and revised in 1975. As a bit-paired layout, shifted keys correspond to toggling bits in the ASCII keycode. This is most visible in the digits on the top row, where shifting give, and , and are paired.

The ECMA-23 layout has two options, being the same as the ISO 2530 or the ANSI-X4.14 bit-paired layout.

In the UK, ECMA-23 layout keyboards were used on most 8-bit computers such as the Acorn BBC computers and the earlier Atom and Systems, the Amstrad CPC series, and (to an extent) the ZX Spectrum. While bit-paired layouts have generally given way to typewriter layouts it remains as the Japanese keyboard layout.

Technical details


The most common layouts are:
 * The and  keys may be at the left as per ISO2530 or at the right as per ANSI-X4.14.
 * Character 96 is generated either with Shift- with a singleton key, or with Shift- with  a singleton key.
 * Underline may be generated with Shifted- instead of with its own key. If this is done then Shift- is used to generate character 96.
 * If a key is labelled it should be at the top-right; if a key is labelled  it should be at the bottom-right.
 * If the key to the left of is not, it is.
 * "BBC Micro": ECMA23/ANSI with Shift- generating character 96
 * "Japan": ECMA23/ANSI with Shift- generating character 96 and an extra key to the right of generating
 * "PC": ECMA23/ISO with Shift- generating character 96