INT 16h,  10h (16)       Extended Keyboard Read                          many

Returns the next character in the keyboard buffer; if no character is
available, this service waits until one is available. This service is
provided to support the enhanced (101/102-key) keyboard.

On entry:      AH         10h

Returns:       AL         ASCII character code
AH         Scan code


Notes:         This service is supported only on the AT dated
11/15/85 and after, PC XT dated 1/10/86 and after,
and XT-286.

The scan codes are the numbers representing the
location of the key on the keyboard. As new keys
have been added and the keyboard layout rearranged,
this numbering scheme has not been consistent with
its original purpose. See the list of scan codes.

If the character is a special character, AL will be
0 and the value in AH will be the extended scan code
for the key. See the list of scan codes.

Use the scan codes to differentiate between keys
representing the same ASCII code, such as the plus
key across the top of the keyboard and the gray plus

After the character has been removed from the
keyboard buffer, the keyboard buffer start pointer
(at 0:041Ah) is increased by 2. If the start pointer
is beyond the end of the buffer, the start pointer
is reset to the start of the keyboard buffer.

If no character is available at the keyboard, an INT
15h, Service 90h (Device Busy), will be issued for
the keyboard, informing the operating system that
there is a keyboard loop taking place and thereby
allowing the operating system to perform another

After every character is typed, an INT 15h, Service
91h (Interrupt Complete), is issued. This allows the
operating system to switch back to a task that is
waiting for a character at the keyboard.

See Service 00h for an equivalent service that works
with all keyboards, not supporting the new keys on
the enhanced (101/102-key) keyboard.

See also: INT 16h, 00h
See also: INT 16h, 05h
See also: Scan Codes

INT 16h, 10h (16) Extended Keyboard Read many