Sharp MZ-5500 Tehnical Manual page 52

°Software (in reference to the circuit example in the preceding page)
\j
CSEG
ORG 100B
MOV AL, 0
,OUT OAEll, AL
~\
MOV AL, 07H
OUT OAH, AL
Iput
MOV
AL,
40H ;Only high order
OUT
50H, AL ;4 bits are valid
OUT
OCH, AL
Set DHA start
address to
40000H
I
MOV AL, 0
OUT 06H, AL
OUT 06H, AL
Se
t
DMA add ress
offset
MOV AL, OFFH
OUT
07H, AL
MOV AL, 7FH
Set DMA word
set
DMA transfel
~i
OUT 07B, AL
size to 32KB
J
MOV AL, 47H
OUT
OBH, .
AL
CH3
MOV
AL, 03H
OUT
OAH, AL
Clear DMAC
eH] mask
MOV AL, 80H
OUT
OAEB, AL
Li: IN AL, 40H
AND
AL, 40B
JZ.i Li
MOV AL, 0
OUT
OAEB, 0
XOR CX, CX
XOR DX, DX
INT 224
END
Enable
*1: IR-26 is used simply as an input port.
4q