CGROUP GROUP VECTOR,CODESEGVECTOR SEGMENT AT 0H DB 6CH DUP(?) ;FILLERTIME_LO DW ? ;DOS TIMETIME_HI DW ? ;DOS TIMEVEC_IP DW ;CLOCK UPDATE VECTOR IPVEC_CS DW ;CLOCK UPDATE VECTOR CSVECTOR ENDSCODESEG SEGMENT PARA ASSUME CS:CODESEG,DS:CGROUP ORG 100HCLK PROC FAR JMP SETUP ;ATTACH TO DOSINTRPT LABEL DWORDINT_IP DW 0 ;OLD UPDATE VECTOR IPINT_CS DW 0 ;OLD UPDATE VECROR CSTICKS DW 0 ;TICK COUNTERSCR_OFF DB 0,0 ;SCREEN OFFSET IN BUFFERCRT_PORT DW 0 ;SCREEN STATUS PORTflag db 0TIME DB 8 DUP(':',0BH) ;TIME SAVE AREACLK_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 COUNTERNO_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 INTERRUPTSWAIT1: 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 MOVEWAIT2: 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 INTERRUPTCLK ENDPUPDATE 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 flagHOUR: CMP AX,0CH ;CONVERT TO HOURS JLE H1 mov flag,1 ;set to pm SUB AX,0CH JMP HOURH1: 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 RETUPDATE ENDPSETUP: 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 ADDRMONO: 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) ;FILLERCODESEG ENDS END CLK
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