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Assembly Source File | 1986-11-22 | 23.5 KB | 517 lines

Comment * Multi Spooler Ver. 2 for the IBM PC by Rich Winkel Columbia, Mo. For free distribution only Mspool2 Features Allows spooling up to 4 printers simultaneously. Supports both parallel and serial printers in any combination. Has a user selectable buffer size up to 63K bytes. Sensitive to competing demands for CPU time. Won't slow down foreground jobs. Allows cancellation of an on-going print operation. Can be 'disabled' for use with programs which are incompatible with it's operation. Usage: To install the spooler, at the DOS prompt type: MSPOOL a b c where: a (= 1 - 4) represents the four possible printers on the PC. (1, 2 & 3 correspond to LPT1, LPT2 & LPT3) b (= 1 - 9) represents the number of 7K chunks of memory to set aside for the spooler buffer. c (= 1 - 4) is an optional parameter used when you wish the output to be directed to a serial port. (1 and 2 correspond to COM1 and COM2) Once the spooler is installed, the user need not worry about it further; it will begin intercepting all print operations and buffering them. However, the operation of the spooler can be modified after it has been installed, if the need arises. After the spooler has been installed, if you type: MSPOOL a where 'a' is the same 'a' you used to install it, you are presented with three options: Purge, Disable or Enable. These are as follows: Purge: Drops any characters remaining in the spooler buffer. This has the effect of canceling any printing operation currently taking place. Disable: A few programs for the PC operate in a way which interferes with MSPOOL's ability to send characters to the printer. The result is that MSPOOL captures the characters, but doesn't actually begin printing them until it's buffer is full or you exit your program. 'Disabling' the spooler (prior to running your program) keeps the number of characters in it's buffer from growing. That is, every time the spooler intercepts a character, it prints a character. If it's buffer is empty, it's as if it wasn't there at all. It simply prints the character it gets when it gets it. If there are characters in the buffer at the time the offending program is invoked, then when it gets a character to print, it fetches the next character in line and prints it, and puts the new character at the end of the queue. Enable: Re-enables spooling. Hitting any key other than P, D or E has no effect. Notes: To spool to a serial printer, first initialize the COM port with the MODE command: MODE COMc:baud,parity,databits,stopbits etc. DO NOT use the P (continuous retry) option. Then install MSPOOL: MSPOOL a b c. This will route all output for LPTa through the spooler to the COMc port. DO NOT use the MODE redirect command. (i.e. don't use MODE LPT#:=COMn) To spool to more than one printer, just run the spooler repeatedly, specifying each printer in turn. When spooling to more than one printer, in certain circumstances (see tech hype below) the last spooler loaded will have priority, then the second to last. In order for the Purge, Disable, Enable routine to work, you should load the spooler(s) last among the 'resident' routine(s) which intercept the printer I/O interrupt. Once the spooler is installed, it's output cannot be re- directed to another port, so programs written for this purpose (such as QSWAP) will not work. Technical hype: This spooler intercepts 2 interrupts: Printer I/O (INT 17H), and Keyboard I/O (INT 16H). At installation, it stores the old vectors for these interrupts internally and substitutes it's own addresses in the interrupt vector table. Any call to print is checked as to whether it references the spooler's printer. If not, it is passed on to the the old printer I/O handler. (could be another spooler, GRAPHICS.COM, the ROM routine etc.) If it does reference the spooler's printer, the character is put in the spooler's buffer, and the buffer is checked to see if it's full. If not, the spooler returns to the calling program. Otherwise, the spooler prints the next character waiting in the buffer, then returns. If the spooler has been 'disabled', it always prints the next character in the buffer, regardless of whether the buffer is full. Whenever a program makes a keyboard I/O call (INT 16H), the spooler checks whether it has a character to print in it's buffer. If not, it passes control to the old keyboard I/O routine (could be another spooler, the ROM routine etc.). Otherwise, it makes one attempt to print a character. It then checks to see if the keyboard call will require the keyboard I/O routine to wait for a character to be entered from the keyboard if no character is already in the keyboard buffer. If not, it passes control to the old keyboard I/O handler. Otherwise, it looks at the BUFFER_HEAD and BUFFER_TAIL words in the ROM BIOS data area to determine if there is a character in the keyboard buffer. If there is, it passes control. Otherwise, it begins looping, repeatedly attempting to print and checking the keyboard buffer until it either runs out of characters or a character is entered at the keyboard. It is during this looping process that the most recently installed spooler will get the highest priority. Whenever mspool is run, it checks where the printer I/O interrupt vector is pointing to determine whether it has already been installed. If it doesn't find a copy of itself there, it assumes it is not installed and continues with installation. If there is a copy of itself, it checks to see whether the copy is configured to intercept calls to the same printer as was specified in it's own parameter list (parm 1). If not, it gets the segment for the next printer I/O handler up the line from the copy and repeats the same procedure until it either lands in unfamiliar territory or finds a spooler configured for it's printer. If it finds one with the proper configuration, it presents you with the 'Purge, Disable, Enable' option. Otherwise, it continues with installation. During installation, the spooler is patched in accordance with the parameters passed to it by DOS, to customize for parallel or serial printing, buffer size, LPT number and the addresses of the old interrupt routines gotten from the interrupt vector table. The legal ranges for the printer number and serial port number are due to the fact that there is space for 4 ports in both the printer and RS-232 tables. * PAGE 60,132 ; MULTI SPOOLER 2 BY RICH WINKEL. FOR FREE DISTRIBUTION ONLY. ; CERTAIN AREAS OF CODE ARE MODIFIED BY THE INITIALIZATION ROUTINE TO ; CUSTOMIZE FOR THE PRINTER AND BUFFER SIZE WHILE MINIMIZING THE NEED ; FOR (SLOW) INDIRECT ADDRESSING. (QUITE A HACK, EH?) ; THE MODIFIED CODE AREAS ARE MARKED ON THE RIGHT WITH '*'. ; CR EQU 0DH ;CARRIAGE RETURN ; BOTTOM SEGMENT AT 0H ORG 058H KBDIP DW ? ;INT VECTOR FOR KBDCS DW ? ;KEYBOARD I/O PRTIP DW ? ;INT VECTOR FOR PRTCS DW ? ;PRINTER I/O ORG 41AH KBHEAD DW ? ;ROM BIOS DATA; POINTERS TO HEAD AND KBTAIL DW ? ;TAIL OF KEYBOARD BUFFER BOTTOM ENDS ; MSPOOL SEGMENT ASSUME CS:MSPOOL ORG 6H SEGTOP DW ? ;NUMBER OF BYTES AVAIL IN SEGMENT ORG 80H UPALEN DB ? ;UNFORMATTED PARM AREA LENGTH ; ORG 100H MAIN PROC NEAR JMP INIT ;JUMP TO INITIALIZATION HEAD DW OFFSET PRTNUM ;POINTER TO LAST CHAR STORED IN BUFFER TAIL DW OFFSET PRTNUM ;POINTER TO LAST CHAR PRINTED ; ; ROUTINE TO COMPUTE POINTER TO NEXT POSITION IN BUFFER INCR: INC BX ;INCREMENT POINTER CMP BX,1234H ;ARE WE AT END OF BUFFER? * TOP LABEL WORD ;LABEL IS 2 BYTES AFTER CODE TO MODIFY JZ L2 ;YES, WRAP AROUND RET ;OTHERWISE, GET BACK TO CALLER L2: MOV BX,OFFSET PRTNUM;START OF BUFFER RET ;GET BACK ; ; PRINTER I/O INTERRUPT HANDLER PRTINT: STI ;INTERRUPTS BACK ON CMP DX,12H ;DOES THE CALL REFERENCE OUR PRINTER? * LPTN LABEL BYTE ;LABEL IS 1 BYTE AFTER CODE TO MODIFY JZ L3 ;YES, HANDLE IT ;OTHERWISE, JUMP TO NEXT INT HANDLER DB 0EAH ;PREFIX BYTE FOR FAR JUMP PJFARIP DW 0H ;IP FOR " " * PJFARCS DW 0H ;CS FOR " " * L3: OR AH,AH ;PRINT A CHARACTER? JNZ BACK ;NO, REPLY PRINTER READY AND RETURN PUSH BX ;OTHERWISE RECEIVE CHARACTER MOV BX,CS:HEAD ;GET POINTER CALL INCR ;INCR TO POINT TO NEXT BUFFER POSITION MOV CS:[BX],AL ;STORE CHAR IN BUFFER MOV CS:HEAD,BX ;STORE NEW HEAD VALUE MOV AX,BX ;FOR SAFE KEEPING MOV BX,CS:TAIL ;GET TAIL CMP AX,BX ;IS THE BUFFER FULL? TOGGLE LABEL BYTE ;AT BYTE TO MODIFY (SPOOLING DISABLE) JZ FULL ;YES, SO PRINT A CHARACTER * POP BX ;OTHERWISE, RETURN BACK: MOV AH,90H ;PRINTER STATUS READY, SELECTED IRET ;GET BACK TO CALLER FULL: PUSH DX ;PRINT A CHARACTER MOV DX,1234H ;POINTER TO STATUS PORT OF PRINTER * PRTADD1 LABEL WORD ;LABEL IS 2 BYTES AFTER CODE TO MODIFY L5: CALL PRT ;CALL TO PRINT CMP BX,CS:TAIL ;HAS A PRINT OCCURRED? JZ L5 ;NO, TRY AGAIN MOV CS:TAIL,BX ;OTHERWISE, STORE NEW TAIL AND RETURN POP DX POP BX MOV AH,90H ;PRINTER READY, SELECTED IRET ;BYE ; ; KEYBOARD INT HANDLER KBDINT: STI ;INTERRUPTS BACK ON PUSH BX MOV BX,CS:TAIL ;GET POINTER TO LAST CHAR PRINTED CMP BX,CS:HEAD ;WAS IT THE LAST CHAR SPOOLED? JZ L10 ;YES, JUMP TO NEXT INT HANDLER PUSH DX ;OTHERWISE, PRINT A CHARACTER PUSH AX MOV DX,1234H ;POINTER TO PRINTER STATUS PORT * PRTADD2 LABEL WORD ;LABEL IS 2 BYTES AFTER CODE TO MODIFY CALL PRT ;CALL TO PRINT POP AX OR AH,AH ;TEST NATURE OF KBD CALL JNZ L9 ;JUMP IF WE ARE NOT TO WAIT FOR KBD INP PUSH AX ;OTHERWISE, CHECK IF CHAR IN KBD BUFFER PUSH DS XOR AX,AX ;POINT DS TO LOW MEMORY MOV DS,AX ASSUME DS:BOTTOM L7: MOV AX,KBHEAD ;IS THERE A CHAR CMP AX,KBTAIL ;IN THE KEYBOARD BUFFER? JNZ L8 ;YES, JUMP TO NEXT KBD INT HANDLER CMP BX,CS:HEAD ;STILL CHARS TO PRINT? JZ L8 ;NO, ON TO NEXT KBD INT HANDLER CALL PRT ;OTHERWISE, PRINT ANOTHER CHAR JMP SHORT L7 ;DO IT AGAIN L8: POP DS POP AX L9: POP DX MOV CS:TAIL,BX ;STASH LATEST VALUE OF TAIL L10: POP BX DB 0EAH ;PREFIX BYTE FOR FAR JUMP KJFARIP DW 0H ;IP FOR " " * KJFARCS DW 0H ;CS FOR " " * ; ; ROUTINE TO PRINT A CHARACTER TO RS-232 PRT: IN AL,DX ;TEST LINE STATUS REG ** TEST AL,20H ;READY? JNZ MSR ;YES, CHECK MODEM STATUS REG RET ;OTHERWISE, RETURN MSR: INC DX ;POINT TO IT IN AL,DX ;GET STATUS AND AL,30H ;ISOLATE CTS & DSR CMP AL,30H ;BOTH READY? JNZ REQUEST ;NO, SIGNAL DTR AND RTS SUB DX,06H ;ELSE POINT TO XMIT HOLDING REG CALL INCR ;INCREMENT BUFFER POINTER MOV AL,CS:[BX] ;GET CHAR OUT DX,AL ;OUTPUT ADD DX,05H ;POINT BACK TO LSR RET ;GET BACK REQUEST:SUB DX,02H ;POINT TO MODEM CNTL REG MOV AL,03H ;DTR, RTS OUT DX,AL ;OUTPUT INC DX ;POINT BACK TO LSR RET ;GET BACK ** ; ;-------END OF RESIDENT CODE------- ; ; THE FOLLOWING BYTES ARE USED DURING INITIALIZATION ASSUME DS:MSPOOL PRTNUM DB 0H ;FIRST PARM PASSED BUFFSIZE DB 0H ;SECOND COMNUM DB 0H ;THIRD (OPTIONAL) ; ;-------INITIALIZATION ROUTINE------- ; ; FIRST PROCESS PARMS ; INIT: MOV CL,UPALEN ;GET LENGTH OF PARM STRING OR CL,CL ;IS IT ZERO? JZ OVRLOOP ;JUMP OVER PARM PARSING XOR CH,CH ;ZERO FOR LOOPING MOV BX,OFFSET UPALEN+1 ;POINT TO PARM AREA MOV SI,OFFSET PRTNUM-1 ;POINT TO PLACE TO STASH PARMS PROCESS:MOV AL,[BX] ;GET THE PARM CMP AL,' ' ;GET RID OF SPACES JZ LOOP1 INC SI ;POINT TO NEXT PARM STORAGE BYTE CMP SI,OFFSET COMNUM;PROTECT AGAINST USER ABUSE JA NOGOOD ;EXCESSIVE NUMBER OF PARMS GIVEN MOV [SI],AL ;FOR SAFE KEEPING INC BX ;POINT TO NEXT SPOT IN UPA CMP BYTE PTR [BX],' ';WAS THE PARM A SINGLE CHAR? JZ LOOP2 ;GOOD CMP BYTE PTR [BX],13;CARRIAGE RETURN? JZ LOOP2 ;MUST BE AT END OF UPA NOGOOD: JMP L25 ;ELSE INVALID PARM LOOP1: INC BX ;POINT TO NEXT CHAR IN UPA LOOP2: LOOP PROCESS ;BACK FOR MORE ; ; PROCESS FIRST PARM ; OVRLOOP:MOV AL,PRTNUM ;GET FIRST PARM CMP AL,0H ;NO PARM PASSED? JNZ L14 MOV AL,'1' ;THEN ASSUME '1' L14: CMP AL,'1' ;CHECK FOR BOTTOM OF LEGAL RANGE JB NOGOOD ;BAD PARM CMP AL,'4' ;TOP OF LEGAL RANGE JA NOGOOD ;BAD PARM SUB AL,'1' ;CONVERT TO CORRESPONDING HEX NUMBER-1 MOV LPTN-1,AL ;MODIFY CODE ; ; NOW CHECK IF SPOOLER FOR THIS PRINTER IS ALREADY INSTALLED ; XOR DX,DX MOV ES,DX MOV AX,ES:PRTCS ;GET SEGMENT FOR PRT INT FROM TABLE CLD ;FORWARD DIRECTION FOR COMPARE L19: MOV ES,AX ;GET IN RIGHT SEGMENT MOV CX,0010H ;COMPARE 10H BYTES MOV SI,OFFSET L3 ;PREPARE TO COMPARE MOV DI,SI L20: CMPSB ;DOES IT MATCH? JNZ CONTINU ;NO, NOT INSTALLED, CONTINUE INSTALLING LOOP L20 ;COMPARE NEXT BYTES MOV AL,ES:LPTN-1 ;THERE'S A SPOOLER THERE, BUT IS IT CMP AL,LPTN-1 ;CONFIGURED FOR OUR PRINTER? PATCHON LABEL BYTE ;PTR TO BYTE TO PATCH AT TOGGLE JZ L21 ;YES, PURGE, DISABLE OR ENABLE? ;NO, CHECK NEXT PRT INT HANDLER UP THE ;LINE MOV AX,ES:PJFARCS ;GET CS FOR NEXT HANDLER PATCHOFF LABEL BYTE ;PTR TO BYTE TO PATCH AT TOGGLE JMP SHORT L19 ;CHECK IF IT'S ANOTHER SPOOLER L21: MOV AH,09H ;ASK IF WANT TO PURGE, DISABLE OR MOV DX,OFFSET MSG4 ;ENABLE INSTALLED SPOOLER INT 21H ;DOS CALL L22: MOV AH,01H ;GET A CHARACTER FROM THE KEYBOARD INT 21H ;DOS CALL AND AL,'_' ;FORCE UPPER CASE CMP AL,'P' ;CHECK FOR PURGE JZ PURGE ;YES, PURGE CMP AL,'D' ;CHECK FOR DISABLE JZ DISABLE ;SWITCH OFF CMP AL,'E' ;CHECK FOR ENABLE JZ ENABLE ;SWITCH ON INT 20H ;OTHERWISE, BACK TO DOS PURGE: MOV AX,ES:HEAD ;GET HEAD FROM OTHER SPOOLER MOV ES:TAIL,AX ;PUT IT IN TAIL INT 20H ;BACK TO DOS DISABLE:MOV AL,PATCHOFF ;TURN IT OFF MOV ES:TOGGLE,AL INT 20H ;BYE ENABLE: MOV AL,PATCHON ;TURN IT ON MOV ES:TOGGLE,AL INT 20H ;BYE ; ; SPOOLER IS NOT YET INSTALLED, PROCEED WITH INSTALLATION ; CONTINU:XOR AH,AH ;FOR FUTURE USE MOV AL,COMNUM ;COMM PORT SPECIFIED? OR AL,AL JZ PARINIT ;NO, INSTALL FOR PARALLEL PRINTER CMP AL,'1' ;ELSE CHECK FOR LEGAL RANGE (1-4) JB EMSG ;BAD PARM CMP AL,'5' JB L18 ;GOOD PARM EMSG: JMP L25 ;ERROR: INVALID PARM L18: SUB AL,'1' ;CONVERT TO CORRESPONDING HEX NUMBER-1 SHL AL,01H ;FOR WORD OFFSET INTO RS232 TABLE MOV BX,05H ;TO ADJUST COM PORT ADDR POINTER JMP SHORT GETADDR ;GO GET THE ADDRESS PARINIT:MOV AL,LPTN-1 ;RETRIEVE LPT NUMBER SHL AL,01H ;MULT BY 2 FOR WORD OFFSET IN PRT TABLE ADD AL,08H ;TO POINT TO BASE OF PRINTER TABLE MOV BX,01H ;TO ADJUST PARALLEL PORT ADDR POINTER MOV CX,DS ;NOW OVERLAY SERIAL PRINT ROUTINE WITH MOV ES,CX ;PARALLEL PRINT ROUTINE MOV SI,OFFSET PARAPTCH;POINT TO PATCH FOR PARALLEL PRINTER MOV DI,OFFSET PRT ;POINT TO SERIAL PRINT ROUTINE MOV CX,PPLEN ;LENGTH OF PARAPTCH ;DIRECTION FLAG IS ALREADY CLEAR REP MOVSB ;MAKE PATCH GETADDR:ADD AX,400H ;POINT TO PROPER TABLE (RS232 OR PARAL) MOV SI,AX ;PREPARE TO GET ENTRY IN TABLE MOV ES,DX ;GET IN RIGHT SEGMENT MOV AX,ES:[SI] ;GET ENTRY FROM TABLE OR AX,AX ;IS ANYTHING THERE? JNZ DEVOK ;YES, CONTINUE JMP L26 ;ERROR: DEVICE NONEXISTENT DEVOK: ADD AX,BX ;POINT TO PROPER STATUS PORT OF DEVICE MOV PRTADD1-2,AX ;PATCH CODE MOV PRTADD2-2,AX ;DITTO ; ; PROCESS BUFFER SIZE PARAMETER ; MOV AL,BUFFSIZE ;GET BUFFER SIZE PARAMETER CMP AL,'1' ;CHECK FOR BOTTOM OF LEGAL RANGE JB L25 ;ERROR IF BELOW CMP AL,'9' ;CHECK FOR TOP OF LEGAL RANGE JA L25 ;ERROR IF ABOVE SUB AL,'0' ;CONVERT TO CORRESPONDING HEX NUMBER XOR AH,AH MOV CX,1C00H ;MULTIPLY BY MUL CX ;7K TO GET BUFFER SIZE ADD AX,OFFSET PRTNUM;ADD RESIDENT CODE SIZE TO GET TOTAL CMP AX,SEGTOP ;IS THERE ROOM? JA L27 ;NO, ERROR MOV TOP-2,AX ;MODIFY CODE ; ; NOW THE FINAL INSTALLATION ; MOV ES,DX ;GET VECTORS FROM THE INT TABLE AT SEG 0 MOV AX,ES:PRTIP ;IP FOR INT 17H MOV PJFARIP,AX ;MODIFY CODE MOV AX,ES:PRTCS ;CS FOR INT 17H MOV PJFARCS,AX ;MODIFY CODE MOV AX,ES:KBDIP ;IP FOR INT 16H MOV KJFARIP,AX ;MODIFY CODE MOV AX,ES:KBDCS ;CS FOR INT 16H MOV KJFARCS,AX ;MODIFY CODE MOV AX,2517H ;USE DOS TO POINT INT 17H TO US MOV DX,OFFSET PRTINT;ADDR OF PRINT INT HANDLER INT 21H ;ADJUST INTERRUPT MOV AX,2516H ;USE DOS TO POINT INT 16H TO US MOV DX,OFFSET KBDINT;ADDR OF KBD INT HANDLER INT 21H ;DO IT MOV AH,09H ;MESSAGE TO USER: MOV DX,OFFSET MSG5 ;'SPOOLER INSTALLED' INT 21H ;DO IT MOV DX,TOP-2 ;GET TOTAL SIZE OF SPOOLER INT 27H ;TERMINATE AND STAY RESIDENT ; ; ERROR MESSAGES ; L25: MOV AH,09H ;MESSAGE: 'BAD PARMS' MOV DX,OFFSET MSG1 INT 21H INT 20H ;ADIOS L26: MOV AH,09H ;MESSAGE: 'NO PORT! MOV DX,OFFSET MSG2 INT 21H INT 20H ;ADIOS L27: MOV AH,09H ;MESSAGE: 'NOT ENUF ROOM!' MOV DX,OFFSET MSG3 INT 21H INT 20H ;ADIOS ; MSG1 DB 'Error: Invalid parameter(s).',0DH,0AH DB 'Parm 1 represents the printer and must be >0 and <5.',0DH,0AH DB 'Parm 2 is the size of the buffer in 7K blocks and must be ' DB '>0 and <10.',0DH,0AH DB 'Parm 3 is the optional COM port to re-direct to, and must ' DB 'be >0 and <5.$' MSG2 DB 'Error: Output port non-existent!$' MSG3 DB 'Error: Not enough memory for requested buffer.$' MSG4 DB 'Mspool2 already installed. Purge, Disable, Enable? (P/D/E): $' MSG5 DB 0DH,0AH,09H,'Multi Spooler2 by Rich Winkel',0DH,0AH,0AH DB 09H,'>> Multi Spooler installed <<',0DH,0AH,'$' ; ; ;PATCH TO PRINT TO PARALLEL PRINTER (OVERLAYS PRT) ; PARAPTCH LABEL BYTE IN AL,DX ;GET PRINTER STATUS TEST AL,80H ;READY? JZ L99 ;NO, GET BACK ; THE FOLLOWING 3 BYTES ARE A CALL TO THE INCR ROUTINE. ; HOWEVER, THE OFFSET WORD FOR THE CALL HAD TO BE ADJUSTED ; FOR THE ACTUAL LOCATION OF THIS ROUTINE WHEN IT IS ; USED, SINCE IT WOULD BE PATCHED OVER THE ROUTINE 'PRT'. DB 0E8H ;PREFIX BYTE FOR INTRASEGMENT CALL DW SETOFF + OFFSET PARAPTCH - JNK JNK EQU $ MOV AL,CS:[BX] ;GET CHAR DEC DX ;POINT TO CHAR OUT PORT OUT DX,AL ;GET IT GONE INC DX ;POINT TO INC DX ;STROBE PORT MOV AL,1DH ;ZAP IT OUT DX,AL MOV AL,1CH ;STROBE OFF OUT DX,AL DEC DX ;POINT BACK TO STATUS PORT L99: RET ;GET BACK PPLEN EQU $-OFFSET PARAPTCH ;LENGTH OF PATCH ABOVE SETOFF EQU OFFSET INCR - OFFSET PRT ;TO USE TO ADJUST CALL IN ;PATCH FOR PARA PRINTER MAIN ENDP MSPOOL ENDS END MAIN