Function 03h (3)         Auxiliary Character Input

Waits for a character from the standard auxiliary device. Checks for
Ctrl-Break and Ctrl-C.

On entry:      AH         03h

Returns:       AL         Character read

                                                                          

This function inputs a character into AL from the standard auxiliary
device, which is normally the first serial port. (At startup, PC-DOS
initializes the first serial port to 2400 baud, eight data bits, one
stop bit, and no parity.)

Notes:         If a Ctrl-Break (Ctrl-C) is detected, an INT 23h is
generated.

Input is unbuffered and not interrupt-driven; if
your program can't process the characters fast
enough, data may be lost.

This function does not monitor the status of the
serial port. For greater control, use the ROM-BIOS
services (Interrupt 14h).

See also: INT 14h, 03h
See also: 3Fh

03h (3) Auxiliary Character Input