Specifications

Application Examples
;
;***********************************************************
;* *
;* SYSTEM EQUATES *
;* *
;***********************************************************
;
; * ZT 8809A 8259A REGISTER EQUATES BY PORT ADDRESS *
;
; REG A ICW,OCW2,OCW3,IRR,ISR,IL
PORT_A_8809A EQU 0020H ; PORT_A
ICW1_8809A EQU 00010001B ; EDGE, CASCADE
OCW2_8809A EQU 01100010B ; SPECIFIC EOI FOR IR2
;
; REG B ICW2,3,4,OCW1,IMR
PORT_B_8809A EQU 0021H ; PORT B
ICW2_8809A EQU 00001000B ; TYPES 8-15D
ICW3_8809A EQU 00000000B ; NO SLAVES
ICW4_8809A EQU 00011101B ; 8088, NORM EOI, BUF MASTER
OCW1_8809A EQU 00000000B ; ENABLE ALL INTERRUPTS FOR
; STD DOS USE
;
; * ZT 8809A 8254 REGISTER EQUATES BY PORT ADDRESS *
;
CNTRL_WORD EQU 0043H ; TIMERS’ CONTROL WORD
TIMER0 EQU 0040H ; COUNTER/TIMER 0 DATA
TIMER1 EQU 0041H ; COUNTER/TIMER 1 DATA
TIMER2 EQU 0042H ; COUNTER/TIMER 2 DATA
TMR2_MODE2 EQU 10110100B ; SET TIMER 2 TO MODE 2
;
; * ZT 8809A PRINTER PORT REGISTER EQUATES BY PORT ADDRESS *
;
PRTR_DATA EQU 0378H ; PRINTER DATA PORT
PRTR_STAT EQU 0379H ; PRINTER STATUS PORT
PRTR_CTRL EQU 037AH ; PRINTER CONTROL PORT
4-7