Specifications

Application Examples
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;* *
;* PROCEDURES *
;* *
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INIT_PIC_8809A PROC
;
; THIS PROCEDURE IS CALLED TO INITIALIZE THE 8259A PIC.
; THE PIC IS INITIALIZED TO: SINGLE MODE, EDGE TRIG-
; GERED, INTERRUPT TYPES8-15DFORIRQS 0-7 RE-
; SPECTIVELY, 8088 MODE, NORMAL (NON-SPECIFIC) END-
; OF-INTERRUPT, IRQ LINES 0-7 ENABLED.
MOV DX,PORT_A_8809A ; ADDRESS THE FIRST BYTE
MOV AL,ICW1_8809A ; WRITE 1ST ICW
OUT DX,AL ; OUTPUT 1ST ICW
MOV DX,PORT_B_8809A
MOV AL,ICW2_8809A
OUT DX,AL ; WRITE 2ND ICW
MOV AL,ICW3_8809A
OUT DX,AL ; WRITE 3RD ICW
MOV AL,ICW4_8809A ; WRITE 4TH ICW
OUT DX,AL ; OUTPUT 4TH ICW
MOV AL,OCW1_8809A ; WRITE OCW1
OUT DX,AL ; OUTPUT MASK
RET
INIT_PIC_8809A ENDP
;
INIT_PIC_8840 PROC
;
; THIS PROCEDURE IS CALLED TO INITIALIZE THE 8259A PIC ON
; THE ZT 8840. THE PIC IS INITIALIZED TO: SINGLE MODE, EDGE
; TRIGGERED, INTERRUPT TYPES8-15DFORIRQS 0-7 RE-
; SPECTIVELY, 8088 MODE, NORMAL (NON-SPECIFIC) END-
; OF-INTERRUPT, IRQ LINES 0-7 ENABLED.
;
MOV DX,PORT_A_8840 ; ADDRESS THE FIRST BYTE
MOV AL,ICW1_8840 ; WRITE 1ST ICW
OUT DX,AL ; OUTPUT 1ST ICW
MOV DX,PORT_B_8840
MOV AL,ICW2_8840
OUT DX,AL ; WRITE 2ND ICW
MOV AL,ICW3_8840
OUT DX,AL ; WRITE 3RD ICW
MOV AL,ICW4_8840 ; WRITE 4TH ICW
OUT DX,AL ; OUTPUT 4TH ICW
MOV AL,OCW1_8840 ; WRITE OCW1
OUT DX,AL ; OUTPUT MASK
RET
INIT_PIC_8840 ENDP
;
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