15
12.3
EXAMPLE 3(USING ASSEMBLY LANGUAGE)
Write a short paragraph of assembly language to read the input buffer.
己知
RAM.
Program is as follows: ( BASE the I/O base address set)
MOV
DX
，
BASE
；
Set Dx as I/O index register
MOV AX
，
GENERAL_ INPUT
；
put address
of GENERAL_ INPUT
in AX
OUT
DX
，
AX
；
write to setup index register
MOV DX
，
BASE+2
；
Set up Dx for data R/W
IN AX
，
DX
；
read data from
GENERAL_ INPUT
register
