An introduction to the Thai language

Keyboard layout

In 1988, the Thai Industrial Standard Institute (TISI) adopted the Ketmanee layout as the standard for computers, a layout already used by Thai typewriting systems. In 1990 and 1991, the Thai API Consortium (TAPIC), a collective group of Thai computer experts from the private and educational sectors, adopted an extension of the Ketmanee layout, TIS 820-2531, as the new Thai standard. The IBM Keyboard 191 (PDF, 152KB) supports this standard.

In 1995, the standard became TIS 820-2538, a modification of TIS 820-2531, which included ancient Thai characters. TIS 820-2538 is not widely used, however. Most Thai computer manufacturers and operating systems such as Windows still use TIS 820-2531 as their primary keyboard layout.

Language group selection.

Thai keyboards are usually bilingual. The Thai alphabet layout is typically accompanied by United States Latin alphabet layout. Language selection can be done manually using the Alt, Right-Shift or Left-Shift keying combinations.

Key function

Alt + Left-Shift: changes keyboard group to English.
Alt + Right-Shift: changes keyboard group to Thai.

Caps Lock

Most keys on the Thai keyboard have two, unrelated characters assigned per key; one in the level 1 position and one in the level 2 position. This is similar to the numbers on a Latin keyboard, the number 3 is in the level 1 position and the # is in the level 2 position. The Caps Lock key has the same effect as holding down the Shift Key while typing. For the Thai language group, when the Caps Lock key is ‘on’ the characters in the level 2 positions will be entered until the Caps Lock key is pressed again and turned ‘off’. For characters in the English language group, the Caps Lock key causes the uppercase characters to be entered.

How to input Thai characters and character combinations

The consonant or middle vowel is entered first on the base line; the cursor then moves to the next position. Next, the above and below vowels are entered (optional) and stacked on the character to the left of the cursor. There is no cursor movement in this action.
The following writing order and combinations are considered as valid composed characters:

All other character combinations are considered invalid.