Power-Programmierung/CD1.mdf/assemblr/library/sampler1/clock.asm

Assembly Source File | 1985-02-28 | 4.4 KB | 139 lines

CGROUP     GROUP VECTOR,CODESEG
VECTOR     SEGMENT AT 0H
     DB    6CH DUP(?)        ;FILLER
TIME_LO  DW    ?            ;DOS TIME
TIME_HI  DW    ?            ;DOS TIME
VEC_IP     DW                ;CLOCK UPDATE VECTOR IP
VEC_CS     DW                ;CLOCK UPDATE VECTOR CS
VECTOR     ENDS

CODESEG  SEGMENT PARA
     ASSUME CS:CODESEG,DS:CGROUP
     ORG   100H
CLK     PROC  FAR
     JMP   SETUP            ;ATTACH TO DOS
INTRPT     LABEL DWORD
INT_IP     DW    0            ;OLD UPDATE VECTOR IP
INT_CS     DW    0            ;OLD UPDATE VECROR CS
TICKS     DW    0            ;TICK COUNTER
SCR_OFF  DB    0,0            ;SCREEN OFFSET IN BUFFER
CRT_PORT DW    0            ;SCREEN STATUS PORT
flag     db    0
TIME     DB    8 DUP(':',0BH)       ;TIME SAVE AREA
CLK_INT  LABEL NEAR
     PUSH  AX            ;SAVE REGISTERS
     PUSH  CX
     PUSH  DI
     PUSH  SI
     PUSH  DS
     PUSH  ES
     PUSHF                ; AND FLAGS
     CALL  CS:[INTRPT]        ;DO OLD UPDATE INTERRUPT
     MOV   CX,0040H         ;GET SEGMENT OF DOS TABLE
     MOV   DS,CX            ;PUT IN DS
     MOV   CX,CS:TICKS        ;GET TICK COUNT
     INC   CX            ;INCREMENT IT
     CMP   CX,20        ;01F4H           ;HAS A MINUTE GONE BY?
     JB    NO_MINUTE        ;NO, MOVE ON
     CALL  UPDATE            ;YES, UPDATE CLOCK AND
     MOV   CX,0            ; RESET TICK COUNTER
NO_MINUTE:
     MOV   CS:TICKS,CX        ;SAVE UPDATED TICK COUNT
     MOV   CX,0B000H        ;GET VIDEO SEGMENT
     MOV   ES,CX            ;PUT IN ES
     MOV   DX,CS:CRT_PORT        ;GET CRT STATUS PORT ADDR
     MOV   DI,WORD PTR CS:SCR_OFF  ;GET SCREEN BUFFER OFFSET
     LEA   SI,CS:TIME        ;GET DOS TIME
     MOV   CX,16            ;SET UP TO MOVE 10 BYTES
     CLI                ;DISABLE OTHER INTERRUPTS
WAIT1:     IN    AL,DX            ;READ CRT STATUS
     TEST  AL,1            ;CHECK FOR VERTICAL RETRACE
     JNZ   WAIT1            ;WAIT FOR RETRACE LOW
     MOV   AH,CS:[SI]        ;GET FIRST BYTE TO MOVE
WAIT2:     IN    AL,DX            ;GET CRT STATUS
     TEST  AL,1            ;CHECK FOR VERTICAL RETRACE
     JZ    WAIT2            ;WAIT FOR RETRACE HIGH
     MOV   ES:[DI],AH        ;MOVE BYTE TO SCREEN
     INC   DI            ;INCREMENT INDEX
     INC   SI
     LOOP  WAIT1            ;MOVE NEXT BYTE
     STI                ;ENABLE INTERRUPTS
     POP   ES            ;RESTORE REGISTERS
     POP   DS
     POP   SI
     POP   DI
     POP   CX
     POP   AX
     IRET                ;RETURN FROM INTERRUPT
CLK     ENDP
UPDATE     PROC  NEAR
     PUSH  AX            ;SAVE REGISTERS
     PUSH  BX
     PUSH  CX
     PUSH  DX
     PUSH  DS
     MOV   AX,0040H         ;GET ADDRESS OF DOS TABLE
     MOV   DS,AX            ;PUT IN DS
     MOV   AX,TIME_HI        ;GET HIGH BYTE OF DOS TIME
     mov   flag,0            ;am flag
HOUR:     CMP   AX,0CH            ;CONVERT TO HOURS
     JLE   H1
     mov   flag,1            ;set to pm
     SUB   AX,0CH
     JMP   HOUR
H1:     AAM                ;CONVERT TO ASCII
     ADD   AX,3030H
     LEA   BX,CS:TIME        ;GET ADDRESS OF TIME AREA
     MOV   CS:[BX],AH        ;SAVE HOURS FIRST DIGIT
     MOV   CS:[BX+2],AL        ;SAVE HOURS SECOND DIGIT
     MOV   AX,TIME_LO        ;GET DOS TIME LOW BYTE
     MOV   CX,8H            ;CONVERT TO MINUTES
     SHR   AX,CL
     MOV   DX,3CH
     MUL   DL
     SHR   AX,CL
     AAM                ;CONVERT TO ASCII
     ADD   AX,3030H
     MOV   CS:[BX+6],AH        ;SAVE MINUTES FIRST DIGIT
     MOV   CS:[BX+8],AL        ;SAVE MINUTES SECOND DIGIT
     mov   byte ptr cs:[bx+12],'a'
     cmp   flag,0            ;is it am?
     jz    goahead
     mov   byte ptr cs:[bx+12],'p'
goahead:
     mov   byte ptr cs:[bx+14],'m'
     POP   DS            ;RESTORE REGISTERS
     POP   DX
     POP   CX
     POP   BX
     POP   AX
     RET
UPDATE     ENDP
SETUP:     MOV   AX,0            ;GET ADDRESS OF VECTOR TABLE
     MOV   DS,AX            ;PUT IN DS
     CLI                ;DISABLE FURTHER INTERRUPTS
     MOV   AX,[VEC_IP]        ;GET ADDRESS OF OLD UPDATE IP
     MOV   CS:[INT_IP],AX        ;SAVE IT
     MOV   AX,[VEC_CS]        ;GET ADDRESS OF OLD UPDATE CS
     MOV   CS:[INT_CS],AX        ;SAVE IT
     MOV   VEC_IP,OFFSET CLK_INT ;PUT ADDRESS OF CLK IN VECTOR IP
     MOV   VEC_CS,CS        ;PUT CS OF CLK IN VECTOR CS
     STI                ;ENABLE INTERRUPTS
     MOV   AH,0FH            ;READ VIDEO STATUS
     INT   10H
     SUB   AH,8            ;SUBTRACT 8 CHAR TIME FROM NCOLS
     SHL   AH,1            ;MULTIPLY BY 2 FOR ATTRIBUTE
     MOV   CS:SCR_OFF,AH        ;SAVE SCREEN TIME LOCATION
     MOV   WORD PTR CS:CRT_PORT,03BAH  ;SAVE MONO STATUS PORT ADDR
     TEST  AL,4            ;CHECK FOR COLOR MONITOR
     JNZ   MONO            ;IF MONO, MOVE ON
     ADD   WORD PTR CS:SCR_OFF,8000H   ;ADD COLOR OFFSET TO TIME OFFSET
     MOV   WORD PTR CS:CRT_PORT,03DAH  ;SAVE COLOR STATUS PORT ADDR
MONO:     CALL  UPDATE            ;DO FIRST UPDATE & PRINT TIME
     MOV   DX,OFFSET SETUP        ;GET END ADDRESS OF NEW INTERRUPT
     INT   27H            ;TERMINATE AND REMAIN RESIDENT
     DB    117 DUP(0)        ;FILLER
CODESEG  ENDS
     END   CLK