Specifications

Application Examples
; REG #6 MODEM STATUS REG (R)
PORT_MODS EQU 006H ; MODEM STATUS
DCTS EQU 01H ; DELTA CTS
DDSR EQU 02H ; DELTA DSR
TERI EQU 04H ; TRAIL RING IND.
DSLSD EQU 08H ; DELTA RECV SIG.
CTS EQU 10H ; CLEAR TO SEND
DSR EQU 20H ; DATA SET READY
RI EQU 40H ; RING INDICATOR
RLSD EQU 80H ; RECV LINE DECT.
;
;
;***********************************************************
;* *
;* MACRO DEFINITIONS *
;* *
;***********************************************************
;
GET MACRO SRC
MOV DX,SRC ;; GET I/O PORT
IN AL,DX ;; INPUT DATA
ENDM
;
PUT MACRO DST
MOV DX,DST ;; GET I/O PORT
OUT DX,AL ;; OUTPUT DATA
ENDM
;
;***********************************************************
;* *
;* INTERRUPT POINTERS SEGMENT *
;* *
;***********************************************************
;
; INTERRUPT POINTER TABLE LOCATED AT 0H
;
INT_POINTERS SEGMENT
ORG 0
;
TYPE_0 DD ? ; DIV BY ZERO, NOT USED
TYPE_1 DD ? ; SINGLE STEP, "
TYPE_2 DD ? ; NON-MASKABLE INT
TYPE_3 DD ? ; BREAKPOINT, NOT USED
TYPE_4 DD ? ; OVERFLOW, "
;
; INTERRUPT POINTER TABLE IS LOCATED JUST ABOVE THE FIRST EIGHT
; INTERRUPT TYPES.
;
ORG 8*4
;
4-20