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Assembly Source File | 1984-04-08 | 8.5 KB | 294 lines

PAGE 60,128 TITLE Asynchronous Print Program - SPOOLER.ASM V1.0 PAGE COMMENT * PROGRAM: SPOOLER.ASM Version 1.0 AUTHOR: Valdis Skuja DATE: September 15,1982 MODULE DESCRIPTION ------------------ This program sets up an environment in which any output for the printer is buffered before being printed. After the output is placed into the buffer control is passed back to the caller. The output is then printed asynchronously. The asynchronous print routine is given control at each tick of the system timer, at which time it keeps sending the buffered print output to the printer until the printer is busy. Using this method the program printing does not have to wait for the printed output to complete before continuing, therefore making better use of the CPU and allows the user to run other programs as the printer is still printing. The buffer size is set in the program as 16K, but this can be changed by changing the values in the define statements for "BUFSIZE" and "BUFFER_AREA" and then reassembling and relinking the program. To invoke this program it must be assembled and linked as SPOOLER.EXE then while in DOS issue the command SPOOLER. When invoked the program will remain resident and can only be removed by re-booting DOS. Do not invoke the program more than once without re-booting as it will grab an additional 16K of your RAM each time it is called. Anyone having any questions or problems about using this program can contact me at 223-2528, and I will try to help you if I can. Valdis Skuja. * BIOS_DATA SEGMENT AT 40H ORG 8H PRINTER_BASE DW 4 DUP(?) ORG 3FH MOTOR_STATUS DB ? MOTOR_COUNT DB ? ORG 6CH TIMER_LOW DW ? TIMER_HIGH DW ? TIMER_OFL DB ? BIOS_DATA ENDS STACK SEGMENT PARA STACK 'STACK' DB 10 DUP('STACK ') STACK ENDS CSEG SEGMENT PARA PUBLIC 'CODE' ASSUME CS:CSEG,DS:BIOS_DATA,ES:CSEG,SS:STACK INIT_ROUTINE PROC FAR JMP START ;BR. AROUND BUFFER FLAGS DB 0 ;FLAGS BYTE BF_FULL EQU 80H ;BUFFER FULL BF_EMPTY EQU 40H ;BUFFER EMPTY IO_ACTIVE EQU 20H ;IO CURRENTLY ACTIVE SOFTWARE_INT EQU 10H ;SOFTWARE INTERRUPT NOT_FULL EQU 7FH ;BUFFER NOT FULL NOT_EMPTY EQU 0BFH ;BUFFER NOT EMPTY IO_NOT_ACTIVE EQU 0DFH ;NO IO ACTIVE NOT_SOFTWARE EQU 0EFH ;NOT SOFTWARE INT. ; INTA00 EQU 20H INTA01 EQU 21H EOI EQU 20H ;END OF INTERUPT ; BUFSIZE DW 16384 ;BUFFER SIZE PRINTER_@ DW 0 ;PRINTER ADDRESS FIRST_CHAR DW 0 ;FIRST CHAR. POINTER LAST_CHAR DW 0 ;LAST CHAR. POINTER BUFFER_AREA DB 16384 DUP(?) ;BUFFER AREA 24K END_OF_BUF EQU $ ;END OF BUFFER START: PUSH AX ;SAVE AX CONTENTS PUSH DS ;SAVE DS CONTENTS OR FLAGS,BF_EMPTY ;SET BUFFER EMPTY MOV DX,OFFSET PRINTER_INT ;GET PRINTER INT. RTN. MOV AX,CS ;GET SEG PTR. MOV DS,AX ;SET INT "40" CSEG MOV AH,25H ;DOS CALL - SET INT. MOV AL,40H ;INDICATE INT. "40" INT 21H ;CALL DOS MOV DX,OFFSET PRINT_IO ;GET PRINT IO RTN. MOV AX,CS ;GET SEG PTR. MOV DS,AX ;SET INT "17" CSEG MOV AH,25H ;DOS CALL - SET INT. MOV AL,17H ;REPLACE INT "17" INT 21H ;CALL DOS MOV DX,OFFSET TIMER_INT ;GET TIMER_INT TRN MOV AX,CS ;GET SEG PTR. MOV DS,AX ;SET INT "8" CSEG MOV AH,25H ;DOS CALL - SET INT. MOV AL,08H ;REPLACE INT "8" INT 21H ;CALL DOS PUSH DS ;SAVE DS PUSH DX ;SAVE DX MOV DX,BIOS_DATA MOV DS,DX MOV DX,PRINTER_BASE ;@ OF 1ST PRINTER MOV PRINTER_@,DX ;SAVE PRINTER @ ADD DX,2 ;POINT TO OUTPUT PORT MOV AL,8 ;SET INIT LINE LOW OUT DX,AL MOV AX,1000 INIT_LOOP: DEC AX ;LOOP FOR RESET TO TAKE JNZ INIT_LOOP ;INIT_LOOP MOV AL,0CH ;INT. OFF TO START OUT DX,AL MOV DX,OFFSET BUFFER_AREA ;LOCATE BUFFER AREA MOV FIRST_CHAR,DX ;AND SET UP THE FIRST MOV LAST_CHAR,DX ;AND LAST CHAR POINTERS POP DX ;RESTORE DX POP DS ;RESTORE DS PUSH ES ;PUSH PGM PREFIX @ MOV AX,CS ;CURRENT CSEG PUSH CX ;SAVE CX MOV CX,ES ;@ OF PGM PREFIX SUB AX,CX ;OFFSET FROM PGM. PRFX. MOV CL,4 SHL AX,CL ;MULT. BY 16 MOV DX,AX ;SAVE FOR LATER POP CX ;RESTORE CX ADD AX,OFFSET NEXT_INSTR ;CALC NEXT INSTR OFFSET PUSH AX ;SAVE NEXT INST OFFSET RET ;GOTO NEXT INSTR.76 NEXT_INSTR: POP DS ;RESTORE DS POP AX ;RESTORE AX ADD DX,OFFSET PGM_END ;LOCATE END OF PGM. INT 27H ;END BUT STAY RESIDENT INIT_ROUTINE ENDP ; ; PRINTER_INT PROC NEAR ASSUME CS:CSEG,DS:CSEG,ES:CSEG,SS:STACK PUSH SI ;SAVE SI PUSH DS ;SAVE DS PUSH ES ;SAVE ES PUSH AX ;SAVE AX PUSH BX ;SAVE BX PUSH CX ;SAVE CX PUSH DX ;SAVE DX MOV SI,CSEG MOV DS,SI ;SET UP DS MOV ES,SI ;SET UP ES NEXT_CHAR: TEST FLAGS,BF_EMPTY ;BUFFER EMPTY? JZ CHECK_FOR_EMPTY ;B.I.N JMP PRINTER_INT_RET ;RETURN FROM INTERRUPT CHECK_FOR_EMPTY: MOV SI,FIRST_CHAR ;OFFSET TO PRINT CHAR CMP SI,LAST_CHAR ;IS THIS LAST CHAR. JNE NOT_LAST_CHAR ;B.I.N OR FLAGS,BF_EMPTY ;SET BUFFER EMPTY NOT_LAST_CHAR: CLD ;CLEAR DIRECTION FLAG ; TO INCREMENT SI LODSB ;GET CHAR IN AL CMP SI,OFFSET END_OF_BUF ;END OF BUFFER? JNE PRINT_THE_CHAR ;NO, BRANCH MOV SI,OFFSET BUFFER_AREA ;BEGINNING OF BUFFER PRINT_THE_CHAR: MOV DX,PRINTER_@ ;GET PRINTER ADDR. MOV CX,100 ;SET BUSY LOOP COUNTER OUT DX,AL ;PRINT THE CHAR. INC DX ;POINT TO STATUS PORT WAIT_NOT_BUSY: IN AL,DX ;GET PRINTER STATUS TEST AL,80H ;STILL BUSY? JNZ OUT_STROBE ;OUT STROBE LOOP WAIT_NOT_BUSY ;KEEP TRYING AND FLAGS,NOT_EMPTY ;STILL BUSY-SET NOT EMPTY JMP PRINTER_INT_RET ;AND RETURN W/O PRINTING OUT_STROBE: MOV AL,1DH ;STROBE HIGH INC DX ;POINT TO OUTPUT PORT OUT DX,AL MOV AL,1CH ;STROBE LOW OUT DX,AL MOV FIRST_CHAR,SI ;SET NEXT CHAR TO PRINT AND FLAGS,NOT_FULL ;SET BUFFER NOT FULL JMP NEXT_CHAR ;PRINT NEXT CHAR PRINTER_INT_RET: POP DX ;RESTORE DX POP CX ;RESTORE CX POP BX ;RESTORE BX POP AX ;RESTORE AX POP ES ;RESTORE ES POP DS ;RESTORE DS POP SI ;RESTORE SI IRET PRINTER_INT ENDP ; ; PRINT_IO PROC NEAR ASSUME CS:CSEG,DS:CSEG,ES:CSEG,SS:STACK PUSH DI ;SAVE DI PUSH DS ;SAVE DS PUSH ES ;SAVE ES PUSH BX ;SAVE BX MOV DI,CSEG MOV ES,DI ;SET UP ES MOV DS,DI ;SET UP DS OR AH,AH ;PRINT FUNCTION? JNZ PRINT_IO_RET ;NO, RETURN TEST FLAGS,BF_EMPTY ;BUFFER EMPTY? JZ SAVE_NEXT_CHAR ;B.I.N MOV DI,FIRST_CHAR ;GET PTR. TO 1ST CHAR MOV LAST_CHAR,DI ;LAST CHAR = 1ST CHAR STOSB ;MOVE CHAR TO BUFFER AND FLAGS,NOT_EMPTY ;IND. BUFFER NOT EMPTY JMP PRINT_IO_RET ;RETURN TO CALLER SAVE_NEXT_CHAR: MOV BX,LAST_CHAR ;GET LAST CHAR. PTR. INC BX ;POINT TO NEXT CHAR. CMP BX,OFFSET END_OF_BUF ;END OF BUFFER? JNE CHECK_FOR_FULL ;B.I.N MOV BX,OFFSET BUFFER_AREA ;BEGINNING OF BUFFER CHECK_FOR_FULL: CMP BX,FIRST_CHAR ;LAST_CHAR = FIRST_CHAR JNE SAVE_CHAR ;B.I.N OR FLAGS,BF_FULL ;SET BUFFER FULL STI ;START INTERRUPTS FULL_LOOP: TEST FLAGS,BF_FULL ;FULL BUFFER? JNZ FULL_LOOP ;LOOP IF FULL CLI ;STOP INTERRUPTS JMP SAVE_NEXT_CHAR ;TRY AGAIN SAVE_CHAR: MOV LAST_CHAR,BX ;UPDATE LAST_CHAR MOV DI,BX STOSB AND FLAGS,NOT_EMPTY ;IND. BUFFER NOT EMPTY PRINT_IO_RET: POP BX ;RESTORE BX POP ES ;RESTORE ES POP DS ;RESTORE DS POP DI ;RESTORE DI SUB AH,AH ;CLEAR RETURN CODE IRET PRINT_IO ENDP TIMER_INT PROC NEAR ASSUME CS:CSEG,DS:BIOS_DATA STI ;INTERRUPTS BACK ON PUSH DS PUSH AX PUSH DX ;SAVE MACHINE STATE MOV AX,BIOS_DATA MOV DS,AX ;ESTABLISH ADDRESSABILITY INC TIMER_LOW ;INCREMENT TIME JNZ T4 ;TEST_DAY INC TIMER_HIGH ;INCREMENT HIGH WORD OF TIME T4: ;TEST_DAY CMP TIMER_HIGH,018H ;TEST FOR COUNT EQUALLING 24 HOURS JNZ T5 ;DISKETTE_CTL CMP TIMER_LOW,0B0H JNZ T5 ;DISKETTE_CTL ;------ TIMER HAS GONE 24 HOURS MOV TIMER_HIGH,0 MOV TIMER_LOW,0 MOV TIMER_OFL,1 T5: ;DISKETTE_CTL DEC MOTOR_COUNT JNZ T6 ;RETURN IF COUNT NOT OUT AND MOTOR_STATUS,0F0H ;TURN OFF MOTOR RUNNING BITS MOV AL,0CH MOV DX,03F2H ;FDC CTL PORT OUT DX,AL ;TURN OFF THE MOTOR T6: ;TIMER_RET INT 1CH ;TRANSFER CONTROL TO USER ROUTINE INT 40H ;TRANSFER CNTL TO ASYNC. PRINTER RTN. MOV AL,EOI OUT 020H,AL ;END OF INTERRUPT TO 8259 POP DX POP AX POP DS ;RESET MACHINE STATE IRET ;RETURN FROM INTERRUPT TIMER_INT ENDP PGM_END: DB 0 CSEG ENDS ;END OF CODE SEG. END INIT_ROUTINE