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Assembly Source File | 1987-10-19 | 103.6 KB | 2,542 lines

title LPTx : Line PrinTer Output Capture Routine page 60,132 ;------------------------------------------------------------ ; ; MAIN PROGRAM Version 7.00 ; ; (C) Copyright 1987 by Mark DiVecchio, All Rights Reserved ; (C) Copyright 1987 by Kepa Zubeldia, All Rights Reserved ; .xlist ; ;This program is released for use in non-commercial environments. I ;ask commercial users to register the program with a $25 copyright fee for ;each site (any number of users and computers) at which the program is used. ; ; DISCLAMER : this program tries to perform a function which is ; not supported by DOS. It will work sometime and will not work ; other times. That kind of explains why you don't see this type ; of program on the market. ; I have tested it under DOS 2.1 and DOS 3.1. Some users have ; reported trouble when running under DOS 3.x and for other users ; it works fine. USE AT YOUR OWN RISK. ; ; Mark C. DiVecchio ; 10435 Mountain Glen Terrace ; San Diego, CA 92131 ; 619-566-6810 ;------------------------------------------------------------ ; Updates for Version 7.00 6 Oct 87 ; ; Kepa Zubeldia ; Micro Consulting, Inc. ; 1650 Citizens Tower Bldg. ; Oklahoma City, OK 73106 ; (405) 528-8133 ; ; -Added a pop-up window that allows the control of the redirection from within ; an application program. ; -Added a switch for monochrome screens combined with color cards, to cancel ; the color generation and make the window more visible. ; -Deleted the Control-Z that was appended on the last close to a file. ; -Allow for file append when the program is called with the name of a file ; that already exists. The user still has the option of overwriting the file. ; -Added a switch to perform the append automatically. ; -Corrected the -? switch so it works. ; -Assembled with Microsoft MASM V5.0 ; ; The major change is the addition of the pop-up window. The code for this was ; taken from PC Magazine, October 13, 1987, page 401, a productivity utility ; written by Jeff Prosise. It works with CGA, MGA, and EGA. With the EGA it ; will also work in 120 cols. and/or 35 or 43 line modes. Exiting the pop-up ; with an EGA leaves the cursor in underline. This is not a bug, but a feature. ; ; The pop-up window lets you turn redirection on and off from within a ; running program. You first must start LPTx from the command line as ; usual : ; ; lptx output.fil ; ; Then you can press Alt-PrtSc and a pop-up window will appear. When it ; does, the up and down arrow keys select a printer and the right and ; left arrow keys select redirection. The pop-up will state "to file" ; or "to printer" indicating the state of the redirection. ; ; Press <Enter> or <Esc> to close the window. ; ; Remember that you must start LPTx from the command line before the ; pop-up will let you turn redirection on or off. ; ;------------------------------------------------------------ ; Updates for Version 6.00 18 Mar 87 ; ; Added use of Timer Interrupt and Idle interrupt to permit ; writing to disk ; ; Added a switch to inhibit the output of linefeed characters when ; capturing a file. Program strips linefeed character at the ; end of the line if you turn on this switch. The switch is -l on the ; command line when you open a capture file. ; ; This version does not use the PSP swapping of previous versions. ; ;------------------------------------------------------------ ; Updates for Version 5.02 19 Nov 86 ; ; Added -i inactivate option. Must be only option on command line : ; lptx -i ; ; This version adds a check for DOS interuupt 21h ; function 40h for standard printer device = 0004. ; ; This addition was suggested by Dale Letterman of Seattle. ; ; Assembled using MicroSoft MASM v 4.0 ; ; Program is called and used in the same way as version 3.00 ; ; I now enter DOS with interrupts disabled. ; ; Added a switch to inhibit the checking of the Critical Section Flag ; Add -x to the command line the first time that you run LPTx. ; ;------------------------------------------------------------ ; Updates for Version 5.00 13 May 86 ; ; This version also takes over the DOS interuupt 21h and specifically ; checks for function 5. ; If that is the call, LPTx captures the character if LPTx has been ; activated. If it is a DOS call, LPTx assumes that DOS wants LPT1 since ; there is no way for the DOS call to specify a line printer number. ; ; Uses undocumented DOS int 21h calls 50h and 51h. ; 50h Set new current Program Segment Prefix(PSP) from ; segment number in BX ; 51h Get current PSP into BX. ; These calls are used before any file is opened by the resident portion ; of LPTx. There is some concern that DOS puts information about open files ; into the current PSP. Before we open our spooler file, we want to set ; the current PSP to our PSP and then restore it after the file I/O ; is complete. This idea was expressed in PC Magazine May 13, 1986 on page ; 314 in an article by Charles Petzold. ; ; ; This version 5.0 does not obsolete versions 4.0 and 3.0. Those versions ; may work under some conditions where this one does not and vica versa. ;------------------------------------------------------------ ; Updates for Version 4.01 5 May 86 ; ; Had an error in the way LPTx detected if it was already in memory. ; This error existed from back in version 3.00 and may have been ; the cause of this program locking up the system the very first ; time it was called. ;------------------------------------------------------------ ; Updates for Version 4.0 25 April 86 ; ; Assembled using MicroSoft MASM v 4.0 ; ; Program is called and used in the same way as version 3.00 ; ; Modified the code to check if DOS was running when the print interrupt ; occurs. If so the print request is routed back to the regular line ; printer. This will limit the use of this capture program to user ; programs which do their own output without going to DOS. ; ; In turn, this guarantees that we do re-enter DOS. ; ; The trick of saving the DOS stack was dropped in this version and ; I have resorted to another trick which I garnered from the ; following message found on info-ibmpc. I use method number 2. ; ; This version 4.0 does not obsolete version 3.0. That version may ; work under some conditions where this one does not and vica versa. ; This one worked fine for me using DOS 2.1 and 123 version 1.A. ; Will not work with Shift PrtSc. ; comment * Date: Thu, 30 Jan 86 08:47:51 est Subject: File I/O from resident programs To: allegra!seismo!usc-isib.arpa!info-ibmpc Regarding opening up a file when you are terminate-and-stay-resident: Be very careful when you attempt this. Many an FAT has been eaten for lunch when I first tried doing it. Two ways that work like a charm: 1) Take over interrupt 0x28. This interrupt gets called by DOS while its waiting for a key to be hit. Whenever it does get called (your program should not be time critical, btw, as this routine is never called from CPU intensive tasks), it is safe to do with DOS what you will. (Except for certain interruptions, such as Search First and Search Next, which either you'll screw-up for the foreground task, or they'll screw-up for you.) 2) Get the Critical Section Flag by issuing an int 21, with ah=0x34. This returns a pointer to a flag in ES:BX. When this flag is NULL, and interrupts are on, it is safe to play DOS games. Unless you are the last program to take over the interrupt, don't trust the flag word: many "fine" programs like SideKick do not give you a true copy of the flag word on the stack, but rather give a simple "pushf" after interrupts are turned off. * ;end of comment ; ; More information from a message posted on USENIX: ; comment * From sdcsvax!ihnp4!timeinc!greenber Mon Jul 1 05:12:16 1985 Date: 30 Jun 85 17:12:37 CDT (Sun) ----------------------------------------------------------- INT 21 - Internal - Return CritSectFlag Pointer (MSDOS generic) REG AH = 34H On Return: ES:BX points to DOS "Critical Section Flag" When byte pointed to is zero, DOS is supposed to be safe to interrupt. NOT RELIABLE according to Chris Dunford. Examination of DOS 2.10 code in this area indicates that the byte immediately FOLLOWING this "Critical Section Flag" must be 00 to permit the PRINT.COM interrupt to be called. This suggests that checking the WORD pointed to, rather than the BYTE, might increase reliability of the test greatly. ----------------------------------------------------------- INT 28 - Internal routine for MSDOS This interrupt is called from inside the "get input from keyboard" routine in DOS, if and only if it is safe to use INT 21 to access the disk at that time. It is used primarily by the PRINT.COM routines, but any number of other routines could be chained to it by saving the original vector, and calling it with a FAR call (or just JMPing to it) at the end of the new routine. Until PRINT.COM installs its own routine, this interrupt vector simply points to an IRET opcode. ----------------------------------------------------------- * ;end of comment ; ;------------------------------------------------------------ ; Updates for Version 3.0 ; ; This version is fully compatible with IBM's PRINT command and ; hopefully most other print spoolers. I changed the method by which ; LPTx determines if a resident copy of itself is already in memory. ; ;------------------------------------------------------------ ; This program intercepts the BIOS interrupt 17, the line printer ; interrupt. It will redirect the output of LPT1, LPT2, or LPT3 to a disk ; file. All three redirects may be active at the same time. ; ; ; Background: ; ; The basic problem with this type of program is that PC-DOS as written ; by Microsoft is not re-entrant. That means that if DOS is in control when ; the print interrupt occurs, you can not call DOS again to do some other ; function. Therefore, LPTx can not call DOS to write the captured print ; data to disk. Version 3.00 of LPTx tries to get around this by making ; PC-DOS re-entrant. Version 4.00 of LPTx gets around this by not ever ; trying to re-enter DOS. ; ;*******This Program Must be Converted to a .COM file before running ****** ; Assemble with : ; masm lptx; ; link lptx; ; exe2bin lptx,lptx.com ; erase lptx.obj ; erase lptx.exe ; ;----------------------------------------------------------------- .list if1 %out Pass 1 - Including Macros - v6.00 ; .xlist ;----------------------------------------------------------------- ; ; Macros ; display macro msg mov DX,offset msg mov AH,DISPLAY_OUTPUT int DOS_CALL endm ; ; For the PC-AT: ; POPF macro described in the IBM Personal Computer ; Seminar Proceedings Volume 2, Number 4 September 1984 ; QUOTE ; "If the system microprocessor executes a POPF instruction in either ; the real or the virtual address mode with CPL <= IOPL, then a ; pending maskable interrupt (the INTR pin active) may be improperly ; recognized after executing the POPF instruction even if maskable ; interrupts were disabled before the POPF instruction and the value ; popped had IF=0. If the interrupt is improperly recognized, the ; interrupt is still correctly executed. This errata has no effect ; when interrupts are enabled in either real or virtual address mode. ; The errata has no effect in the virtual address mode when ; CPL > IOPL." ; popff macro ;use POPFF instead of POPF local popem,skip ;simulate popping flags using IRET jmp short skip ;jump around iret popem: iret ;pop CS,IP,flags skip: push CS call popem ;call within segment ;program will continue here endm ; call_dos macro ;Enter DOS with interrupts disabled cli int DOS_CALL sti endm ; ; .list else %out Pass 2 endif ;----------------------------------------------------------------- NULL equ 0 OFF equ 0 ON equ 1 EMPTY equ 0 BEL equ 7 CR equ 13 LF equ 10 DOLLAR equ '$' COLON equ ':' BACKSLASH equ '\' BLANK equ ' ' DASH equ '-' DOS_CALL equ 21h ; REQ equ 00B91h ;LPTx request flag ACK equ 0ABCBh ;LPTx acknowledge flag ; BUFSIZE equ 4096 ;size of DMA buffer DISPLAY_OUTPUT equ 9 ;for DOS call DEF_DRIVE equ 19h CREATE_FILE equ 3Ch OPEN_FILE equ 3Dh CLOSE_FILE equ 3Eh WRITE_FILE equ 40h DELETE_FILE equ 41h LSEEK_FILE equ 42h DEF_PATH equ 47h FIND_FILE equ 4Eh ;----------------------------------------------------------------- ; p_block struc ; ; data structure - these variables are used only in the ; memory resident copy of LPTx. BX is set to point to the offset of the ; allocation of this structure for the selected LPT ; NOTE : all of the labels in this structure are required as place ; holders even if not referenced. Used by the initialization calls ; later on. ; active db OFF ;ON = this LPTx is on, OFF = off handle dw NULL ;handle of disk file used by this LPT filen db 'a:\lptx' ;space for redirection disk file name pnum db '0' ;default to '0' just in case db '.lst',NULL db ' ' db ' ' bufcntr dw EMPTY ;bytes used in DMA buffer for this LPT request db OFF ;ON indicates a write request is active ;for this LPT prt_status db 10h ;printer status for this LPT linefeed db ON ;ON = output a linefeed ;OFF = don't output a linefeed buffer db BUFSIZE dup(0) ;data buffer for this LPT ; p_block ends ; ;----------------------------------------------------------------- ; bios_data segment at 40h org 4Ah crt_cols dw ? ;number of display columns org 4Eh crt_start dw ? ;video page offset address org 63h addr_6845 dw ? ;CRTC base address org 87h infobyte label word ega_info db ? ;EGA info byte bios_data ends ; ;----------------------------------------------------------------- ; subttl Main Code page %out Assembling CODE Segment cseg segment para public 'CODE' assume CS:cseg,DS:nothing,SS:nothing org 100h lptx: jmp lptx_start ; ; What follows are three allocations of the Structure p_block ; One for each line printer that we can support. ; With this, all three line printers have DMA buffers and flag ; variables. ; BX is used to point to the offset of the allocation currently in use ; Line printer 1 lpt1 p_block <,,,'1'> ; Line printer 2 lpt2 p_block <,,,'2'> ; Line printer 3 lpt3 p_block <,,,'3'> ; crit_flag db OFF ;set to ON if critical error occured off_crit dw 0 ;save old critical error address seg_crit dw 0 ; csect_off dw 0 ;pointer to Critical Section flag csect_seg dw 0 cerrf_off dw 0 ;pointer to Critical Error flag cerrf_seg dw 0 ; cs_switch can be cleared by the transient copy of LPTx cs_switch db ON ;enable check of Critical Section flag P_NORMAL equ 90h ;Printed selected and ready P_TIMEOUT equ 01h ;Time out save_psp dw 0 ;Save area for User's PSP Segment Address lptx_psp dw 0 ;Our PSP Segment Address byte_count dw 0 ;to save DOS byte count busy db OFF ;ON indicates write is taking place sound db OFF ;ON uses speaker to indicate progress of LPTx ; flag_10h db 0 ;status of interrupt 10h flag_13h db 0 ;status of interrupt 13h request_popup db 0 ;status of processing request adapter db 2 ;0=MDA, 1=CGA, 2=EGA ;The following 5 lines MUST not be changed. They are dynamically set at Run Time video_segment dw 0B800h ;video segment address border_attr db ? ;window border attribute text_attr db ? ;window text attribute menu_attr db ? ;menu line attribute video_page db ? ;current video page cursor_mode dw ? ;cursor shape cursor_pos dw ? ;cursor position cursor_addr dw ? ;cursor CRTC address new_cursor dw 0607h ;Popup cursor shape nocolors db 0 ;monochrome only menu_choice db 0 ;popup cursor line (0,1,2) screen_buffer db 48 dup('SCREEN BUFFER ') ;10 * 34 * 2 bytes color_attr db 0,0B8h,10h,07h,3fh ;black/blue,white/black,hi-white/blue nocolor_attr db 0,0B8h,70h,07h,70h ;mono mono_attr db 0,0B0h,70h,07h,70h enable_values db 2Ch,28h,2Dh,29h,2Ah,2Eh,1Eh ; ; Old interrupt vector addresses old_08h dd 0 ;address of old int 08h routine old_09h dd 0 ;address of old int 09h routine old_10h dd 0 ;address of old int 10h routine old_13h dd 0 ;address of old int 13h routine old_17h dd 0 ;address of old int 17h routine old_21h dd 0 ;address of old int 21h routine old_28h dd 0 ;address of old int 28h routine ; old1Bh_segment dw ? ;old interrupt 1Bh segment old1Bh_offset dw ? ;old interrupt 1Bh offset old23h_segment dw ? ;old interrupt 23h segment old23h_offset dw ? ;old interrupt 23h offset old24h_segment dw ? ;old interrupt 24h segment old24h_offset dw ? ;old interrupt 24h offset ; ; New Stack for Interrupt 17h stk1_save dd 0 ;caller's stack EA db 128 dup('STACK ') stk1 equ this byte - 4 ; New Stack for Interrupts 08h and 28h stk2_save dd 0 ;caller's stack EA db 128 dup('STACK ') stk2 equ this byte - 4 ; New Stack for Popup window process stk3_ss dw 0 ;caller's stack EA stk3_sp dw 0 db 128 dup('STACKP ') stk3 equ this byte - 4 ; ;------------------------------------------------------------------------------ ; Window text ;------------------------------------------------------------------------------ ; ;You will need an editor capable of handling graphics to edit the window. ;I used PC-Write, but old edlin will also work. ;Do not change the width or the depth of the window !!! ; window db "┌──────────────LPTX──────────────┐" db "│ │" menuline1 db "│ lpt1: to PRINTER │" menuline2 db "│ lpt2: to PRINTER │" menuline3 db "│ lpt3: to PRINTER │" db "│ │" db "├────────────────────────────────┤" db "│ Press: to move, to toggle,│" db "│ <Enter> to close window. │" db "└────────────────────────────────┘" menufile1 db "│ lpt1: to FILE │" menufile2 db "│ lpt2: to FILE │" menufile3 db "│ lpt3: to FILE │" ;------------------------------------------------------------------------------ ; Interrupt handler for interrupt 09h (keyboard) ;------------------------------------------------------------------------------ ; keyboard proc near push ax cmp CS:busy,OFF ;program already active? jne kb_regular ; yes, skip processing this key. in al,60h ;look at the hardware register cmp al,55 ;is this PrtSc ? jne kb_regular ; no, process it the old way. sti ;set interrupt enable flag mov ah,2 ;get keyboard shift status int 16h test al,8 ;Alt key also pressed? je kb_regular ; no, process old way. mov CS:request_popup,18 ;set request flag for 1 second. ;now, call keyboard handling routine ; to reset keyboard controller ; and as courtesy to other TSRs. kb_regular: pop ax jmp dword ptr CS:old_09h keyboard endp ; ;------------------------------------------------------------------------------ ;Interrupt 10h handling routine. ;------------------------------------------------------------------------------ video proc near pushf ;push flags onto stack inc flag_10h ;increment flag call dword ptr CS:old_10h ;call BIOS routine dec flag_10h ;decrement flag iret video endp ; ;------------------------------------------------------------------------------ ;Interrupt 13h handling routine. ;------------------------------------------------------------------------------ bdisk proc far pushf ;push flags onto stack inc flag_13h ;set 'busy' flag call dword ptr CS:old_13h ;call BIOS routine pushf ;save output flags dec flag_13h ;clear flag popff ;restore output flags ret 2 ;exit without destroying flags bdisk endp ; ; ;----------------------------------------------------------------- ; ; Interrupt handler for interrupt 17h ; int_17h proc far sti ;interrupts on cmp AH,3 ;AH=3 for LPTx Function jne reg_call ;This is a regular print call jmp ret_ack ;This is an LPTx Call reg_call: push BX ; set up BX to point to the data area for the requested printer cmp DX,0 ;lpt1? jne chk_lpt2 ;no mov BX,offset lpt1 ;offset to LPT1 jmp short bx_set chk_lpt2: cmp DX,1 ;lpt2? jne chk_lpt3 ;no mov BX,offset lpt2 ;offset to LPT2 jmp short bx_set chk_lpt3: cmp DX,2 ;lpt3? jne ill_ptr ;no - bad printer number mov BX,offset lpt3 ;offset to LPT3 bx_set: cmp CS:[BX].active,OFF ;are we active? je sleep17 ;no mov CS:[BX].prt_status,P_NORMAL ;signal ready status cmp AH,1 ;initialize call? je do_nix ;yes cmp AH,2 ;status call? je do_nix ;yes cmp AH,0 ;print call? jne do_nix ;no jmp prt_17 ;we are active do_nix: mov AH,CS:[BX].prt_status ;return print status rtn: pop BX iret ; ill_ptr:mov CS:[BX].prt_status,P_TIMEOUT ;time out status jmp do_nix ; ret_ack: ;return acknowledgement that I'm here ; note : Change REQ & ACK from version to version so two versions ; of LPTx don't get intermixed. cmp DX,REQ ;my flag to detect that LPTx is ;already loaded and alive. jne ret_nak ;return a NAK mov DX,ACK ;Memory resident LPTx answers with ACK push CS ;now set up ES to point to the resident pop ES ; data area ret_nak: iret ;return to calling program ; sleep17:pop BX ;restore BX before we go to sleep jmp dword ptr CS:old_17h ;jump immediate to original handler ; prt_17: push AX ; Start the print process. push BX ; Character is in AL. push CX push DX push DS push ES push SI push DI push BP ; push CS ; DS is used as the segment register pop DS ; for all data during the interrupt ; pushf cli mov SI,SS mov word ptr DS:stk1_save+2,SI ;save caller's stack pointer mov SI,SP mov word ptr DS:stk1_save,SI mov SI,CS mov SS,SI ;give me new bigger stack mov SI,offset stk1 mov SP,SI popff mov DS:[BX].prt_status,P_NORMAL ;signal ready status ;prt_status is set before ;the call to prnt so that prnt ;can change it if the print to ;disk fails call prnt ;print the character ; pushf cli mov SI,word ptr DS:stk1_save mov SP,SI ;restore caller's stack pointer mov SI,word ptr DS:stk1_save+2 mov SS,SI popff pop BP pop DI pop SI pop ES pop DS pop DX pop CX pop BX pop AX jmp do_nix int_17h endp ;----------------------------------------------------------------- ; ; Interrupt handler for interrupt 21h ; int_21h proc far sti ;interrupts on push BX cmp AH,5 ;is this a DOS printer call? je int_21h_5 ;yes cmp AH,40h ;is this a DOS write call? je int_21h_40 ;yes jmp sleep21 ;no - go on to real DOS ; DOS Function 40h - Write to File or Device. DS:DX contains the address ;of data to write. CX contains the byte count. Return AX = byte count. int_21h_40: cmp BX,0004 ;Standard Printer? jne sleep21 ;no - go on to real DOS ; set up BX to point to the data area for the requested printer ; Since we don't know what the standard printer device is, we ; use LPT1 mov BX,offset lpt1 ;offset to LPT1 cmp CS:[BX].active,OFF ;are we active? je sleep21 ;no push AX ;now do it push BX push CX push DX mov CS:byte_count,CX ;save byte count mov BX,DX ;DS:BX points to buffer, CX has byte count cmp CX,EMPTY ;check for zero byte count je prt_21_done loop21_40: mov AL,[BX] ;get a character mov AH,0 ;set up for call to interrupt 17h int 17h ;note : int17h returns a printer status ;in AH but DOS does not define a way ;to return that status inc BX loop loop21_40 prt_21_done: pop DX pop CX pop BX pop AX mov AX,CS:byte_count ;DOS returns byte count jmp exit21 ;to return it to the user. ; int_21h_5: ; DOS Function 5 Printer Output. The Character in DL is output to the ; standard printer device. ; ; set up BX to point to the data area for the requested printer ; Since we don't know what the standard printer device is, we ; use LPT1 mov BX,offset lpt1 ;offset to LPT1 cmp CS:[BX].active,OFF ;are we active? je sleep21 ;no push AX mov AH,0 ;set up for call to interrupt 17h mov AL,DL ;the character int 17h pop AX ;note : int17h returns a printer status ;in AH but DOS does not define a way ;to return it to the user. exit21: pop BX popff ;restore flags clc ;never an error from us ret ;return to caller (regular FAR return) ; sleep21:pop BX ;restore BX before we go to sleep jmp dword ptr CS:old_21h int_21h endp ; ;----------------------------------------------------------------- ; ; PRNT - Print a character in AL ; prnt proc near push DS cmp DS:[BX].active,OFF je prtext ;nothing there? push AX cmp DS:[BX].bufcntr,BUFSIZE/2 ;buffer half full? jne intadd ;no ; ; set write request but don't actually write anything out. ; we hope that the write can take place before the buffer fills up ; mov DS:[BX].request,ON cmp DS:sound,OFF ;sound on? je intadd ;no call horn ;sound horn to indicate buffer ; write request has been made ; intadd: pop AX cmp AL,LF ;is it a linefeed? jne intnolf ;no cmp DS:[BX].linefeed,OFF ;we are stripping linefeeds? je prtext ;yes intnolf: mov DI,BX ;offset of this printer's allocation add DI,offset lpt1.buffer ;add in offset of buffer add DI,DS:[BX].bufcntr ;add in current byte count mov DS:[DI],AL ;stuff it inc DS:[BX].bufcntr cmp DS:[BX].bufcntr,BUFSIZE ;buffer overflow? jne prtext ;no mov DS:[BX].active,OFF ;yes, nothing to do but deactivate ; LPTx cmp DS:sound,OFF ;sound on? je prtext ;no call beep ;sound beep twice to indicate that call beep ;we have been deactivated prtext: pop DS ret ;done prnt endp ;----------------------------------------------------------------- ; ; Critical Error Handler ; crit_int proc far ;got critical error mov CS:crit_flag,ON ; set flag mov AL,0 ;tells DOS to ignore the iret ;error crit_int endp ;----------------------------------------------------------------- ; ; Interrupt handler for interrupt 08h - clock ticks ; ; This function is installed as a handler for hardware interrupt ; type 8. It first calls the previous int 08h handler to service ; the INTEL 8259 Programmable Interrupt Controller. Then it checks ; to see if any write requests are pending. If so, it calls do_save ; and flush to write the buffer to the disk. Note that int_08h ; checks the DOS critical section flag : do_save is called only if ; DOS is available. ; ; This function protects itself against secondary invocations by ; means of the global busy flag. ; int_08h proc far ; call original int 8h handler - ALWAYS pushf call dword ptr CS:old_08h ; now we can process if possible pushf cli cmp CS:busy,OFF ;can we process this? jne i08_exit ;no cmp CS:flag_10h,0 ;video flag set? jne dectime ;yes, then exit cmp CS:flag_13h,0 ;disk flag set? jne dectime ;yes, then exit ; if DOS is in its critical section, we skip the write for now and ; hope that we can write before the buffer fills push DS ; check the critical section flag push SI push BX cmp CS:cs_switch,OFF ;is checking off? je no_cs ;yes, don't check the flag lds SI,dword ptr CS:csect_off cmp byte ptr [SI],OFF jne poptime ;DOS in critical section ;this indicates that we cannot ;do any disk operations at this ;time lds SI,dword ptr CS:cerrf_off cmp byte ptr [SI],OFF jne poptime ;DOS in critical error ;this indicates that we cannot ;do any disk operations at this ;time no_cs: cmp CS:request_popup,0 je no_popup call do_popup no_popup: mov BX,offset lpt1 ;offset to LPT1 cmp DS:[BX].request,ON ;write LPT1 request? jne no_lpt1 ;no call do_save no_lpt1: mov BX,offset lpt2 ;offset to LPT2 cmp DS:[BX].request,ON ;write LPT2 request? jne no_lpt2 ;no call do_save no_lpt2: mov BX,offset lpt3 ;offset to LPT3 cmp DS:[BX].request,ON ;write LPT3 request? jne poptime ;no call do_save poptime: pop BX pop SI pop DS dectime: cmp request_popup,0 je i08_exit dec request_popup i08_exit: popff iret int_08h endp ;----------------------------------------------------------------- ; ; Interrupt handler for interrupt 28h - idle ; ; This function is installed as a handler for hardware interrupt ; type 28h. It first calls the previous int 28h handler. Then it checks ; to see if any write requests are pending. If so, it calls do_save ; and flush to write the buffer to the disk. It does not check the ; Critical Section Flag as int 28h handlers are allowed to perform ; DOS disk I/O but not keyboard I/O since most of the time int 28h ; is called by the keyboard I/O routines when they are waiting ; for a key press. ; ; This function protects itself against secondary invocations by ; means of the global busy flag. ; int_28h proc far ; call original int 28h handler - ALWAYS pushf call dword ptr CS:old_28h ; now we can process if possible pushf cli cmp CS:busy,OFF ;can we process this? jne i28_exit ;no cmp CS:flag_10h,0 ;video flag set? jne i28_exit ;yes, then exit cmp CS:flag_13h,0 ;disk flag set? jne i28_exit ;yes, then exit cmp CS:cs_switch,OFF ;is checking off? je i28_no_cs ;yes, don't check the flag push DS push SI lds SI,dword ptr CS:cerrf_off cmp byte ptr [SI],OFF pop SI pop DS jne i28_exit ;DOS in critical error ;this indicates that we cannot ;do any disk operations at this ;time i28_no_cs: cmp CS:request_popup,0 je i28_nopopup call do_popup i28_nopopup: call do_save i28_exit: popff iret int_28h endp ;----------------------------------------------------------------- ; do_popup proc near mov CS:busy,ON mov CS:request_popup,0 cli mov CS:stk3_ss,SS mov CS:stk3_sp,SP push cs pop ss mov sp,offset stk3 sti ;interrupts on push AX ; Save everything push BX push CX push DX push DS push ES push SI push DI push BP pushf ; mov ah,15 ;get video mode and page int 10h cmp al,3 ;mode 0, 1, 2, or 3? jbe pu_main1 ;yes, then continue cmp al,7 ;mode 7? je pu_main1 ;yes, then continue ;no, we must be in graphics, and ;I don't know how to open a window ;while in graphics... ; ;Restore registers and stack before exit. ; do_pop_exit: popff pop BP pop DI pop SI pop ES pop DS pop DX pop CX pop BX pop AX cli mov ss,CS:stk3_ss mov sp,CS:stk3_sp sti ;interrupts on mov CS:busy,OFF ret ; ;Set DS and ES segment registers. ; pu_main1: push cs ;set DS to code segment pop ds assume ds:cseg mov ax,bios_data ;point ES to BIOS data mov es,ax assume es:bios_data cmp crt_cols,80 ;at least 80 columns displayed? jb do_pop_exit ;no, then exit ; ;Save needed video parameters. ; mov video_page,bh ;active video page mov ah,3 ;get cursor mode and location int 10h mov cursor_mode,cx mov cursor_pos,dx mov dx,addr_6845 ;get CRTC base address push dx ;save it for later mov al,14 ;specify register number out dx,al inc dx ;point DX to data port in al,dx ;read high byte of address mov ah,al ;save it dec dx ;back to index register mov al,15 ;specify register number out dx,al inc dx ;back to data port in al,dx ;read low byte of address mov cursor_addr,ax ;save cursor address ; ;Determine whether an EGA is present and active in the system. ; mov ah,12h ;see if EGA is present mov bl,10h int 10h cmp bl,10h ;did BL return unchanged? je pu_main2 ;yes, then there's no EGA here test ega_info,8 ;is the EGA currently active? jnz pu_main2 ;no, then branch mov adapter,2 ;set ADAPTER for EGA push bx ;save BX mov ax,1130h ;get number of scan lines per char int 10h dec cl ;form cursor definition in CX mov ch,cl sub ch,2 mov new_cursor,cx ;save cursor definition mov si,offset color_attr ;point SI to color parms pop bx ;retrieve BX or bh,bh ;EGA attached to color monitor? je pu_hascolor ;yes, then branch mov si,offset mono_attr ;no, then point SI to mono parms jmp short pu_main4 pu_hascolor: cmp nocolors,0 ;use monochrome only ? je pu_main4 ; no, use color mov si,offset nocolor_attr ;color card with mono screen jmp short pu_main4 ; ;Determine whether the active video adapter is a CGA or an MDA. ; pu_main2: test addr_6845,40h ;is bit 6 of the CRTC address set? jz pu_main3 ;no, then it's monochrome mov adapter,1 ;set ADAPTER for a CGA mov new_cursor,0607h ;define cursor shape mov si,offset color_attr ;point SI to color parms jmp short pu_hascolor pu_main3: mov adapter,0 ;set ADAPTER for an MDA mov new_cursor,0B0Ch ;define monochrome cursor mov si,offset mono_attr ;point SI to mono parms ; ;Set video parameters for color or monochrome. ; pu_main4: push cs ;set ES to the code segment pop es assume es:cseg mov di,offset video_segment ;point DI to destination mov cx,5 ;5 bytes to move cld ;clear DF rep movsb ;transfer the values ; cmp adapter,1 ;disable CGA video jne pu_main7 call disable_cga pu_main7: call save_screen ;save memory to be overwritten call make_screen ;open the Pop-up window call make_status ;update status of the redirection cmp adapter,1 ;enable CGA video jne pu_main8 call enable_cga pu_main8: mov ah,1 ;hide the cursor mov ch,20h int 10h ; ;Wait for a keystroke and return when ESC is pressed. ; pu_mainA: call getkey ;wait for a keypress or al,al ;extended code entered? je pu_main12 ;yes, then branch cmp al,32 ;SPACE pressed? je toggle ;yes, toggle line cmp al,13 ;ENTER pressed? je escape ;yes, then get out cmp al,27 ;ESC pressed? je escape ;yes, then close window and return jmp pu_mainA ;no, then ignore keypress ; ;An extended code was entered. Check for an Alt-character key combination. ; pu_main12: cmp ah,72 ;UpArrow? je upone ;yes, then process it cmp ah,80 ;DownArrow? je downone ;yes, then process it cmp ah,75 ;LeftArrow? je toggle ;toggle line cmp ah,77 ;RightArrow? je toggle ;toggle line jmp pu_mainA ;return for another keypress ; upone: cmp menu_choice,0 ;are we at the top ? jne upone1 ; no, decrement it mov menu_choice,3 ; yes, wrap around upone1: dec menu_choice call make_status ;update status of the redirection jmp pu_mainA downone: cmp menu_choice,2 ;are we at the bottom ? jne downone1 ; no, increment mov menu_choice,-1 ; yes, wrap around downone1: inc menu_choice call make_status ;update status of the redirection jmp pu_mainA toggle: call make_change ;change the state call make_status ;update status of the redirection jmp pu_mainA ; ;Close the Pop-up window in preparation for return. ; escape: cmp adapter,1 ;disable CGA video jne esc1 call disable_cga esc1: call restore_screen ;restore screen contents cmp adapter,1 ;enable CGA video jne esc2 call enable_cga ; ;Restore the cursor's former position in the BIOS data area and the CRTC. ; esc2: mov ah,2 ;set cursor position thru BIOS mov bh,video_page mov dx,cursor_pos int 10h pop dx ;recover CRTC base address mov cx,cursor_addr ;restore cursor address mov al,14 ;CRTC register number out dx,al inc dx mov al,ch out dx,al ;write high byte of address dec dx mov al,15 ;CRTC register number out dx,al inc dx mov al,cl out dx,al ;write low byte ; ;Display the cursor, bypassing EGA cursor emulation logic, and return. ; cmp adapter,2 ;EGA on board? jne esc3 ;no, then branch call show_cursor ;retain current shape jmp do_pop_exit ; exit from popup esc3: mov ah,1 ;restore cursor shape mov cx,cursor_mode int 10h jmp do_pop_exit ; exit from popup do_popup endp ; ;------------------------------------------------------------ ; ; Writes buffer to disk ; do_save proc near mov CS:busy,ON ; set busy flag push AX ; Start the print process. push BX ; Character is in AL. push CX push DX push DS push ES push SI push DI push BP pushf sti ;interrupts on ; push CS ; DS is used as the segment register pop DS ; for all data during the interrupt ; pushf cli mov SI,SS mov word ptr DS:stk2_save+2,SI ;save caller's stack pointer mov SI,SP mov word ptr DS:stk2_save,SI mov SI,CS mov SS,SI ;give me new bigger stack mov SI,offset stk2 mov SP,SI popff ; ; check to see if any write requests are active. ; we do not look at the active flag since the print redirection ; may have been inactivated by the time, we are able to write to ; the disk. ; ; set up BX to point to the data area for the requested printer mov BX,offset lpt1 ;offset to LPT1 cmp DS:[BX].request,ON ;write LPT1 request? jne c28_lpt2 ;no call flush mov DS:[BX].request,OFF c28_lpt2: mov BX,offset lpt2 ;offset to LPT2 cmp DS:[BX].request,ON ;write LPT2 request? jne c28_lpt3 ;no call flush mov DS:[BX].request,OFF c28_lpt3: mov BX,offset lpt3 ;offset to LPT3 cmp DS:[BX].request,ON ;write LPT3 request? jne i28_done ;no call flush mov DS:[BX].request,OFF i28_done: pushf cli mov SI,word ptr DS:stk2_save mov SP,SI ;restore caller's stack pointer mov SI,word ptr DS:stk2_save+2 mov SS,SI popff ; popff pop BP pop DI pop SI pop ES pop DS pop DX pop CX pop BX pop AX mov CS:busy,OFF ret do_save endp ; ;------------------------------------------------------------ ; ; FLUSH - Flush print buffer to disk file ; flush proc near cmp DS:[BX].bufcntr,EMPTY ;buffer empty? jne flush_buf ;no, write it to disk ret ;exit flush_buf: call disk_out ret flush endp ;------------------------------------------------------------ ; ; DISK_OUT - write to disk ; disk_out proc near ;PSP ; push BX ; mov AH,51h ;get current PSP ; call_dos ; mov DS:save_psp,BX ;and save it ; mov BX,DS:lptx_psp ;get our PSP ; mov AH,50h ; call_dos ;set it into DOS ; pop BX ; push ES push DS mov AX,DS ;set up ES mov ES,AX push BX push ES mov AX,3524h ;get old critical error vector call_dos mov DS:off_crit,BX mov DS:seg_crit,ES mov DX,offset crit_int mov AX,2524h call_dos ;trap critical error vector mov DS:crit_flag,OFF ;clear critical error flag pop ES pop BX mov DX,BX ;open file add DX,offset lpt1.filen ;filename mov AL,1 ;open for writing mov AH,open_FILE call_dos mov DS:[BX].handle,AX ;file handle jc disk_err ;error cmp DS:crit_flag,ON ;critical error? je disk_err ;yes push BX mov AH,lseek_FILE mov AL,2 ;end of file mov CX,0 ;offset 0 mov DX,0 mov BX,DS:[BX].handle call_dos pop BX jc disk_err ;some seek error cmp DS:crit_flag,ON ;critical error? je disk_err ;yes mov CX,DS:[BX].bufcntr ;buffer size mov DX,BX ;offset of structure allocation add DX,offset lpt1.buffer ;add offset of buffer within the ; allocation push BX mov AH,write_FILE mov BX,DS:[BX].handle ;file handle call_dos ;buffer address is DS:DX pop BX jnc disk_ok cmp DS:crit_flag,ON ;critical error? je disk_err ;yes cmp AX,DS:[BX].bufcntr ;did DOS write it all? je disk_ok ;yes disk_err: call beep ;ring bell 4 times call beep call beep call beep mov DS:[BX].active,OFF ;turn us off mov DS:crit_flag,OFF ;clear error flag mov DS:[BX].prt_status,P_TIMEOUT ;signal time out error ;then try to close the file ;to save what we can jmp disk_close disk_ok: mov DS:[BX].bufcntr,EMPTY ;set buffer empty disk_close: push BX mov BX,DS:[BX].handle mov AH,close_FILE ;close the file call_dos pop BX disk_exit: pop DS pop ES push DS lds DX,dword ptr DS:off_crit mov AX,2524h ;restore critical error vector call_dos pop DS ; PSP ; push BX ; mov BX,DS:save_psp ;get user's PSP ; mov AH,50h ; call_dos ;set it back into DOS ; pop BX ; ret disk_out endp ; ;-------------------------------------------------------------- ; ; Routine to sound the beeper ; note equ 0a98h ;2712 = 1193180. / 440Hz beep proc near push AX push BX push CX push DX mov AL,0b6h ;select tim 2,lsb,msb,binary out 43h,AL ;set up timer chip mov AX,note ;get note out 42h,AL ;write timer 2 count: lsb... mov AL,AH out 42h,AL ;...and msb in AL,61h mov AH,AL ;save current port setting or AL,3 out 61h,AL ;turn speaker on mov CX,07FFFh beep_lp:loop beep_lp mov AL,AH out 61h,AL ;restore port setting mov CX,03FFFh beep1_lp:loop beep1_lp pop DX pop CX pop BX pop AX ret ;return to caller beep endp ;------------------------------------------------------------------- ; ; Routine to sound a key click ; key_clk equ 036h ;59 = 1193180. / 20,000Hz click proc near push AX push BX push CX mov AL,0b6h ;select tim 2,lsb,msb,binary out 43h,AL ;set up timer chip mov AX,key_clk ;get note out 42h,AL ;write timer 2 count: lsb... mov AL,AH out 42h,AL ;...and msb in AL,61h mov AH,AL ;save current port setting or AL,3 out 61h,AL ;turn speaker on mov CX,0FFh key_lp:loop key_lp mov AL,AH out 61h,AL ;restore port setting mov CX,0FFh key1_lp:loop key1_lp pop CX pop BX pop AX ret ;return to caller click endp ;-------------------------------------------------------------- ; ; Routine to honk the horn ; horn proc near push AX push BX push CX push DX mov AL,0b6h ;select tim 2,lsb,msb,binary out 43h,AL ;set up timer chip mov AX,2e9bh ;2712 = 1193180. / 100Hz out 42h,AL ;write timer 2 count: lsb... mov AL,AH out 42h,AL ;...and msb in AL,61h mov AH,AL ;save current port setting or AL,3 out 61h,AL ;turn speaker on mov CX,07FFFh horn_lp:loop horn_lp mov AL,AH out 61h,AL ;restore port setting mov CX,03FFFh horn1_lp:loop horn1_lp pop DX pop CX pop BX pop AX ret ;return to caller horn endp ;-------------------------------------------------------------------- ;------------------------------------------------------------------------------ ;SAVE_SCREEN saves the contents of the screen that underlie the window. ;------------------------------------------------------------------------------ video_address dw ? ;video address linesum dw ? ; save_screen proc near push ds ;save DS mov ax,bios_data ;point it to BIOS data area mov ds,ax assume ds:bios_data mov ax,crt_cols ;get number of display columns mov linesum,ax ;calculate distance from end of sub linesum,34 ; one line to start of next shl linesum,1 ; accounting for attribute bytes mov bl,6 ;calculate starting addrss (6 lines) mul bl ;result in AX add ax,18 ;add line offset (18 columns) shl ax,1 ;double result for attr bytes mov si,ax ;transfer to SI add si,crt_start ;add page offset mov video_address,si ;save offset address mov ds,video_segment ;then set DS to the video segment mov di,offset screen_buffer ;point DI to storage buffer mov cx,10 ;10 lines to save save_screen1: push cx ;save line count mov cx,34 ;34 characters per line rep movsw ;transfer one line to storage pop cx ;retrieve line count add si,linesum ;point SI to next video line loop save_screen1 ;loop until all lines are saved pop ds ;restore DS assume ds:cseg ret ;exit save_screen endp ; ;------------------------------------------------------------------------------ ;RESTORE_SCREEN writes the stored screen image to video memory. ;------------------------------------------------------------------------------ restore_screen proc near push es ;save ES register value mov di,video_address ;point DI to starting video offset mov es,video_segment ;point ES to video memory mov si,offset screen_buffer ;point DS:SI to screen image mov cx,10 ;10 lines to restore restore1: push cx ;save line count mov cx,34 ;34 characters per line rep movsw ;restore one line pop cx ;retrieve line count add di,linesum ;set DI to next video line loop restore1 ;loop until done pop es ;restore ES ret restore_screen endp ; ;------------------------------------------------------------------------------ ;MAKE_SCREEN writes an image of the Pop-up window to video memory. ;------------------------------------------------------------------------------ make_screen proc near push es ;save ES mov es,video_segment ;point ES:DI to video memory mov di,video_address mov si,offset window ;line 1 mov cx,34 ;do 34 characters mov ah,border_attr ;this makes the top border make0: lodsb stosw loop make0 add di,linesum mov cx,5 ;5 lines of user text make1: push cx call formline add di,linesum pop cx loop make1 mov cx,4 ;4 lines of instructions on bottom mov ah,border_attr make2: push cx mov cx,34 ;do next 34 characters make3: lodsb stosw loop make3 add di,linesum pop cx loop make2 pop es ;restore ES ret make_screen endp ; ;------------------------------------------------------------------------------ ;MAKE_STATUS writes the new status of the redirection window to video memory. ;------------------------------------------------------------------------------ make_status proc near push es ;save ES mov es,video_segment ;point ES:DI to video memory mov di,video_address ;this point to the beginning of w. add di,34 * 2 ;skip over the text add di,linesum ;skip to next line add di,34 * 2 ;skip over the text add di,linesum ;go down one line cmp adapter,1 ;disable CGA video jne msts0 call disable_cga msts0: mov bx,offset lpt1 ;structure #1 cmp ds:[bx].active,OFF ;printer redirected ? mov si,offset menuline1 ; no, text says PRINTER je msts1 mov si,offset menufile1 ; yes, text says FILE msts1: cmp menu_choice,0 ;is this the highlighted choice? je msts2 call formline ; no, display normal jmp short msts3 msts2: call cursline ; yes, display highlighted msts3: add di,linesum ;go down one line mov bx,offset lpt2 ;structure #2 cmp ds:[bx].active,OFF ;printer redirected ? mov si,offset menuline2 ; no, text says PRINTER je msts4 mov si,offset menufile2 ; yes, text says FILE msts4: cmp menu_choice,1 ;is this the highlighted choice? je msts5 call formline ; no, display normal jmp short msts6 msts5: call cursline ; yes, display highlighted msts6: add di,linesum ;go down one line mov bx,offset lpt3 ;structure #3 cmp ds:[bx].active,OFF ;printer redirected ? mov si,offset menuline3 ; no, text says PRINTER je msts7 mov si,offset menufile3 ; yes, text says FILE msts7: cmp menu_choice,2 ;is this the highlighted choice? je msts8 call formline ; no, display normal jmp short msts9 msts8: call cursline ; yes, display highlighted msts9: cmp adapter,1 ;enable CGA video jne msts10 call enable_cga msts10: pop es ;restore ES ret make_status endp ; ;------------------------------------------------------------------------------ ;MAKE_CHANGE changes the status of the redirection. ;------------------------------------------------------------------------------ make_change proc near push es ;save ES cmp menu_choice,0 ;is this the highlighted choice? jne mkchg1 mov bx,offset lpt1 ;structure #1 mkchg1: cmp menu_choice,1 ;is this the highlighted choice? jne mkchg2 mov bx,offset lpt2 ;structure #2 mkchg2: cmp menu_choice,2 ;is this the highlighted choice? jne mkchg3 mov bx,offset lpt3 ;structure #3 mkchg3: cmp ds:[bx].active,OFF ;flip printer redirection je mkchg4 mov ds:[bx].active,OFF ;turn redirection OFF mov ax,ds:[bx].bufcntr ;look at the buffer size or ah,al ;is there something in it ? jz mkchg5 ; no, buffer was empty mov ds:[bx].request,ON ; yes, request a buffer flush. jmp short mkchg5 mkchg4: mov ax,ds:[bx].handle ;get the file handle to check it or ah,al ;if it has ever been used. jz mkchg5 ; no, don't activate mov ds:[bx].active,ON ; yes, activate redirection mkchg5: call click ;give a little noisy feedback pop es ;restore ES ret make_change endp ; ;------------------------------------------------------------------------------ ;FORMLINE is called by MAKE_SCREEN to help with the dirty work. ;------------------------------------------------------------------------------ formline proc near mov ah,border_attr lodsb stosw mov cx,32 ;do next 32 characters mov ah,text_attr form1: lodsb stosw loop form1 mov ah,border_attr lodsb stosw ret formline endp ; ; ;------------------------------------------------------------------------------ ;CURSLINE is called by MAKE_SCREEN to help with the dirty work. ;------------------------------------------------------------------------------ cursline proc near mov ah,border_attr lodsb stosw mov cx,32 ;do next 32 characters mov ah,menu_attr curs1: lodsb stosw loop curs1 mov ah,border_attr lodsb stosw ret cursline endp ; ; ;------------------------------------------------------------------------------ ;DISABLE_CGA and ENABLE_CGA disable and enable CGA video output. ;------------------------------------------------------------------------------ disable_cga proc near mov dx,3DAh ;address of Status Register disable1: in al,dx ;get status test al,8 ;vertical retrace active? je disable1 ;no, then wait sub dx,2 ;MSR address in DX mov al,25h ;value to disable video out dx,al ;disable video output ret disable_cga endp ; enable_cga proc near mov ah,15 ;get video mode int 10h mov bx,offset enable_values ;get value to enable display xlat ;value in AL mov dx,3D8h ;MSR address out dx,al ;enable video output ret enable_cga endp ; ;------------------------------------------------------------------------------ ;GETKEY waits for a keypress and returns the keycode in AX. ;Exit: AX - keycode ;This function is careful to generate int28 for other TSR that may need them ;while the user is waiting to press a key. ;------------------------------------------------------------------------------ getkey proc near mov ah,1 ;check keyboard buffer int 16h jne getkey1 ;jump if buffer contains a keycode int 28h ;no key pressed - issue int 28h jmp getkey ;loop back to try again getkey1: mov ah,0 ;get keycode from buffer int 16h ret ;exit with keycode in AX getkey endp ; ; ;------------------------------------------------------------------------------ ;SHOW_CURSOR displays the cursor and discounts EGA cursor emulation logic. ;Entry: NEW_CURSOR - starting and ending scan lines ;------------------------------------------------------------------------------ show_cursor proc near cmp adapter,2 ;is an EGA currently active? jne cursor1 ;no, then branch push es ;save ES mov ax,bios_data ;point ES to BIOS data area mov es,ax assume es:bios_data push infobyte ;save EGA info byte or ega_info,1 ;disable EGA cursor emulation cursor1: mov ah,1 ;display the cursor mov cx,new_cursor int 10h cmp adapter,2 ;is an EGA active? jne cursor_exit ;no, then exit pop infobyte ;restore EGA info byte pop es ;restore ES assume es:nothing cursor_exit: ret show_cursor endp ; ;-------------------------------------------------------------------- end_res db 0 ; ; This is the end of the memory resident portion of LPTx ; ;-------------------------------------------------------------------- ; ; All of the following data is in the Code Segment ; mach_type db 0 DOS_version db 0 ;Major Version Number db 0 ;Minor Version Number lfeed db ON ;linefeed enable switch appending db 0 ;appending to an existing file drive db 0 ;default drive number 0=A etc. flag_27 db OFF ; 1=make this copy resident wrong_dos db 'DOS 2.0 or later required for LPTx',LF,CR,DOLLAR up_msg db 'LPTx - Line Printer Redirection Program - V7.00' db LF,CR,' Copyright 1987 Mark C. DiVecchio' db LF,CR,' Copyright 1987 Kepa Zubeldia',LF,CR db DOLLAR lptx_resident db LF,CR,'Resident Portion of LPTx Loaded',LF,CR db 'The pop-up window will be activated by Alt-PrtSc' db LF,LF,CR db DOLLAR lptx_err_3 db 'Could not delete file',LF,CR,DOLLAR lptx_over db CR,LF,'File already exists. Do you want to overwrite ' db 'it? (y or n) :',DOLLAR lptx_nc db 'File selection canceled',CR,LF,DOLLAR lptx_lf db 'Stripping Linefeed Characters',CR,LF,DOLLAR lptx_sd_on db 'Sound Enabled',CR,LF,DOLLAR lptx_mono db 'Monochrome only, graphic card ignored',CR,LF,DOLLAR lptx_cs_off db 'Critical Section Checking Disabled',CR,LF,DOLLAR lptx_del db 'File is being overwritten',LF,CR,DOLLAR lptx_cr db LF,CR,DOLLAR lptx_bad db 'Invalid Option',LF,CR db 'Calling sequence:',LF,CR db 'lptx [?] [-m] [-x] [-l] [-i] {-1,-2,-3} {-c -o -a <d:[pathname]filename>}' db LF,CR,DOLLAR lptx_on db LF,CR,'Redirection started. Disk file opened.' db LF,CR,DOLLAR lptx_off db LF,CR,'Redirection ended. Disk file closed.' db LF,CR,DOLLAR lptx_creat db 'Could not create the disk file',LF,CR,DOLLAR lptx_open db 'Could not open the disk file',LF,CR,DOLLAR lptx_gone db LF,'LPTx - Resident portion inactivated',CR,LF,DOLLAR ; HELP screen help_msg db LF,CR,'Calling sequence : ',LF,LF,CR db 'LPTx [?] [-m] [-x] [-l] [-i] -p -f <[d:][\pathname\pathname]filename>' db LF,LF,CR db ' where p = printer number : 1, 2, or 3',LF,CR db ' f = function : o for open a print file' db LF,CR db ' a for append to a print file' db LF,CR db ' c for close a print file' db LF,CR db ' drive letter & pathname are optional' db LF,CR db ' m = monochrome mode only, even with graphics cards' db LF,CR db ' x = disable check of Critical Section Flag' db LF,CR db ' l = strip Linefeed characters from output' db LF,CR db ' i = inactivate LPTx',LF,CR db ' defaults : p = 1',LF,CR db ' f = o',LF,CR db ' The pop-up window is activated with Alt-PrtSc' db LF,CR db DOLLAR ; stat_stat db CR,LF,'LPTx Status :',CR,LF,DOLLAR stat_lp db 'lpt' stat_ptr db ' : ',DOLLAR stat_off db ' not redirected',CR,LF,DOLLAR stat_dir db ' redirected to disk file ' stat_fn db 60 dup (BLANK) ; yn_max db 2 ;max # of char yn_act db 0 yn_in db 2 dup (0) ; ;-------------------------------------------------------------------- ; ; This is the main routine which is executed each time that LPTx is ; called. In this routine, DS points to the data segment which is ; transient. ES points to the data segment which is permanently ; resident. ES:BX points to the data structure for the selected ; line printer, 1, 2, or 3. ; The offsets are the same for both. If this is the first ; time that LPTx is run, then ES=DS. ; lptx_start: push DS ;Save DS xor AX,AX ;clear AX for return IP push AX ;put 0 on stack ; ;to check for machine type look at ; F000:FFFE ; I don't use this currently ; = FF IBM PC ; = FE IBM XT or Portable ; = FD IBM PCjr ; = FC IBM PC AT ; = F9 IBM Convertible mov AX,0F000h mov ES,AX mov BX,0FFFEh mov CL,ES:[BX] ;get machine type mov mach_type,CL ;save machine type ; ;PSP mov lptx_psp,DS ;put away our PSP Segment address ; ; get the DOS version number ; returns zero for pre DOS 2.0 releases mov AH,30h int DOS_CALL ;call DOS mov word ptr DOS_version,AX ; Requires at least version 2.0 and may or may not work ; with versions above 2.1 cmp DOS_version,2 ;is it DOS 2.+ jge dos_ok ;yes display wrong_dos ;print error message mov AH,0 int DOS_CALL ;terminate dos_ok: mov AH,def_drive ;get current default drive int DOS_CALL mov drive,AL ;save the drive number display up_msg ;print program ID mov flag_27,OFF ;to not make resident ; is a copy of LPTx already resident in memory? mov DX,REQ ;check if LPTx is already resident mov AH,3 ;get status - special call int 17h ;call int 17h - BIOS cmp DX,ACK ;my handler sets DX to ACK ;and sets ES je in_core ;LPTx is resident - ES loaded with ; segment address mov flag_27,ON ;to make this copy resident push CS pop ES ;set ES to CS for segment address mov AL,drive add AL,'a' ;make it a letter mov BX,offset lpt1 mov ES:[BX].filen,AL ;put it into the filename mov BX,offset lpt2 mov ES:[BX].filen,AL ;put it into the filename mov BX,offset lpt3 mov ES:[BX].filen,AL ;put it into the filename ; ---------------------------------------------------- in_core: ;ES is ok ; ES now points to resident data area ; set up ES:BX to point to default data structure mov BX,offset lpt1 ;offset - default to LPT1 ;get options and file name ;scan input line for line printer number mov SI,81h ;starting offset mov CL,DS:80h ;length of input line mov CH,0 cmp CX,0 ;nothing? jne cont_scan ;no jmp make_res ;yes, then just make LPTx resident ;if it isn't already ; ; [?] ; HELP printer ; help: display help_msg ;display the HELP screen jmp bail_out ; ; [-m] ; Monochrome monitor, even on graphic card ; mono_only: mov ES:nocolors,1 display lptx_mono jmp short inp_ret ; ; [-a] ; appending to a file, similar to open. ; append: mov appending,1 jmp file_op ; ; cont_scan: cmp byte ptr DS:[SI],'?' ;a ? ? je help ;yes cmp byte ptr DS:[SI],dash ;a dash ? je got_opt ;yes cmp byte ptr DS:[SI],CR ;a carriage return? je scan_done ;yes cmp byte ptr DS:[SI],BLANK ;a blank? je inp_ret ;yes jmp no_b ;assume that we got a file name ;without the -o option inp_ret: inc SI ;ignore blanks loop cont_scan ;continue to scan ; ; Scan of whole line is complete without a "-o", "-a", "-c" or filename scan_done: jmp make_res ; got_opt: ;we got an option inc SI ;to option cmp byte ptr DS:[SI],'1' ;LPT1? jne chk_2 mov BX,offset lpt1 ;offset from ES jmp short inp_ret chk_2: cmp byte ptr DS:[SI],'2' ;LPT2? jne chk_3 mov BX,offset lpt2 ;offset from ES jmp short inp_ret chk_3: cmp byte ptr DS:[SI],'3' ;LPT3? jne chk_fil mov BX,offset lpt3 ;offset from ES jmp short inp_ret chk_fil: ;is it file? cmp byte ptr DS:[SI],'?' ;help ? je help ;yes cmp byte ptr DS:[SI],'o' ;open a file je file_op ;yes cmp byte ptr DS:[SI],'a' ;append to a file je append ;yes cmp byte ptr DS:[SI],'c' ;close a file je file_cl ;yes cmp byte ptr DS:[SI],'m' ;monochrome only ? je mono_only ;yes cmp byte ptr DS:[SI],'x' ;inhibit check for Critical Section? je cs_check_off ;yes cmp byte ptr DS:[SI],'l' ;linefeed switch ? je lf_off ;yes cmp byte ptr DS:[SI],'s' ;enable sound? je sound_on ;yes cmp byte ptr DS:[SI],'i' ;inactivate? jne bad_opt jmp inactivate bad_opt: display lptx_bad ;incorrect option jmp nor_ex ; ; [-x] ; turn OFF Critical Section check ; cs_check_off: mov ES:cs_switch,OFF display lptx_cs_off jmp inp_ret ; ;[-l] ; Turn linefeeds off in captured file ; lf_off: mov lfeed,OFF ;turn LFs off display lptx_lf jmp inp_ret ;continue the scan ; ; [-s] ; turn ON Sound ; sound_on: mov ES:sound,ON display lptx_sd_on jmp inp_ret ; ; [-c] ; close output file ; file_cl:cmp ES:[BX].active,ON ;are we active? jne no_close ;no mov AL,1AH ;CTRL-Z push DS push ES pop DS ;set DS to point to resident ;data segment ; call prnt ;print end of file mark call flush pop DS ;restore DS mov ES:[BX].active,OFF ;make us inactive display lptx_off ;redirection off message no_close: jmp nor_exit ;nothing to close so exit ; ; [-o] ; open a file for ouput ; file_op: ;get the file name inc SI ;to next chracter cmp byte ptr DS:[SI],BLANK ;a blank? jne no_b ;no inc SI ;skip over blank no_b: ; at this point, we have found a new file name. We close the old ; file if one was open cmp ES:[BX].active,ON ;are we active? jne no_cl ;no mov AL,1AH ;CTRL-Z push DS push ES pop DS ;set DS to point to resident ;data segment ; call prnt ;print end of file mark call flush pop DS ;restore DS mov ES:[BX].active,OFF ;make us inactive display lptx_off ;redirection off message no_cl: mov DI,BX ;base of structure add DI,offset lpt1.filen ;add offset of destination push SI ;save pointer to file name ; search for a drive letter inc SI ;should point to a colon if ;one is there cmp byte ptr [SI],COLON ;? je got_drive ;yes get_drive: mov AL,drive ;get drive letter add AL,'a' ;make it a letter mov ES:[DI],AL ;put it in file name inc DI mov byte ptr ES:[DI],COLON ;put in a colon inc DI jmp path_search got_drive: pop SI ;move pointer back to start mov AL,[SI] ;get the given drive mov ES:[DI],AL ;move it sub AL,'a' ;make it a number mov drive,AL ;save the drive number inc SI inc DI mov byte ptr ES:[DI],COLON inc DI inc SI push SI ;save new start pointer path_search: ; now search for a backslash which says that a pathname was given bk_s_lp:cmp byte ptr [SI],BACKSLASH je got_path ;a path cmp byte ptr [SI],CR ;end of the file name? je get_path ;yes with no path inc SI jmp short bk_s_lp ;loop get_path: mov byte ptr ES:[DI],BACKSLASH ;create the path inc DI mov DL,drive ;the current drive inc DL ;bump it for DOS push DS push ES pop DS ;set up DS for DOS mov SI,DI ;set up SI for pathname mov AH,def_path ;get current directory int DOS_CALL ;path goes into DS:SI pop DS ;restore DS cmp byte ptr ES:[SI],NULL ;null path? je null_path ;yes - root directory path_lp: ;now find the end of the string cmp byte ptr ES:[SI],NULL ;null byte marks end of pathname je end_path ;now append the file name inc SI jmp short path_lp end_path: mov byte ptr ES:[SI],BACKSLASH inc SI null_path: mov DI,SI ;DI is destination got_path: pop SI ;restore source of filename ; pick up everything to next blank get_lp: mov AL,DS:[SI] ;character mov ES:[DI],AL ;put it away cmp AL,CR ;was it a Carriage Return? je end_line cmp AL,BLANK ;was it a space? je end_line inc SI inc DI jmp short get_lp ;no so get next character end_line: mov byte ptr ES:[DI],NULL ;zero out the CR or blank ;at the end of the filename ;it becomes an ASCIIZ string sub DI,BX ;now take out the base and cmp DI,offset lpt1.filen ; make sure that we got something jne lptx_make ;file name was ok display lptx_creat ;could not understand the file name jmp nor_exit ;don't stay resident nor_ex: jmp nor_exit lptx_make: ; default DTA used by Find File is set by DOS to an offset of ; 80h into this program's Program Segment Prefix push DS push ES pop DS ;uses DS:DX mov DX,BX add DX,offset lpt1.filen ;file name mov AH,find_FILE mov CX,0 ;normal files only int DOS_CALL ;find first match pop DS jnc lptx_d ;file was found jmp lptx_create ;not there - which is ok ;file already exists lptx_d: cmp appending,1 ;are we in append mode? je lptx_x ; yes display lptx_over mov DX,offset yn_max;input buffer mov AH,0AH int DOS_CALL cmp yn_act,0 ;anything typed? display lptx_cr je lptx_x ;no - try to append cmp yn_in,'y' ;a yes? je lptx_d_yes ;yes cmp yn_in,'Y' ;a yes? je lptx_d_yes ;yes lptx_x: push DS ;we can't overwrite, try to append push ES pop DS ;uses DS:DX mov DX,BX ;base of this LPT's structure add DX,offset lpt1.filen ;file name mov AL,1 ;open for writing mov AH,open_FILE mov CX,0 ;normal files only int DOS_CALL ;find first match pop DS jnc creat_ok display lptx_open ;could not open the file display lptx_nc jmp nor_exit ;don't stay resident lptx_d_yes: display lptx_del push DS push ES pop DS ;uses DS:DX mov DX,BX add DX,offset lpt1.filen ;file name mov AH,delete_FILE int DOS_CALL ;delete file pop DS jnc lptx_create ;ok its gone display lptx_err_3 ;can't delete it jmp nor_exit lptx_create: ; create the file push DS push ES pop DS ;uses DS:DX mov DX,BX ;base of this LPT's structure add DX,offset lpt1.filen ;file name mov AH,create_FILE mov CX,0 ;normal files only int DOS_CALL ;find first match pop DS jnc creat_ok display lptx_creat ;could not create the file jmp nor_exit ;don't stay resident creat_ok: ;now close the file push BX mov ES:[BX].handle,AX ;save the handle, for popup to know. mov BX,AX ;AX was loaded by the create file ; call mov AH,close_FILE ;close the file int DOS_CALL pop BX display lptx_on ; set the program up for writing mov ES:[BX].bufcntr,EMPTY ;set buffer empty mov ES:[BX].active,ON ;set us on mov AL,lfeed mov ES:[BX].linefeed,AL ;save linefeed switch make_res: cmp flag_27,ON ;make this one resident? je resident ;yes jmp nor_exit ;no ; resident: push ES push BX ; get old interrupt handler addressses mov AL,17h ;get current vector address for 17h mov AH,35h int DOS_CALL mov word ptr old_17h,BX mov word ptr old_17h[2],ES ;save it for later use mov AL,08h ;get current vector address for 08h mov AH,35h int DOS_CALL mov word ptr old_08h,BX mov word ptr old_08h[2],ES ;save it for later use mov AL,09h ;get current vector address for 09h mov AH,35h int DOS_CALL mov word ptr old_09h,BX mov word ptr old_09h[2],ES ;save it for later use mov AL,10h ;get current vector address for 10h mov AH,35h int DOS_CALL mov word ptr old_10h,BX mov word ptr old_10h[2],ES ;save it for later use mov AL,13h ;get current vector address for 13h mov AH,35h int DOS_CALL mov word ptr old_13h,BX mov word ptr old_13h[2],ES ;save it for later use mov AL,DOS_CALL ;get current vector address for 21h mov AH,35h int DOS_CALL mov word ptr old_21h,BX mov word ptr old_21h[2],ES ;save it for later use mov AL,28h ;get current vector address for 28h mov AH,35h int DOS_CALL mov word ptr old_28h,BX mov word ptr old_28h[2],ES ;save it for later use ; ; Set LPTx up as the new int 17h interrupt handler mov AX,2517h ;set interrupt vector mov DX,offset int_17h ;BIOS printer int DOS_CALL ; ; Set LPTx up as the new int 08h interrupt handler mov AX,2508h ;set interrupt vector mov DX,offset int_08h ;Timer int DOS_CALL ; ; Set LPTx up as the new int 09h interrupt handler mov AX,2509h ;set interrupt vector mov DX,offset keyboard ;Keyboard int DOS_CALL ; ; Set LPTx up as the new int 10h interrupt handler mov AX,2510h ;set interrupt vector mov DX,offset video ;Video int DOS_CALL ; ; Set LPTx up as the new int 13h interrupt handler mov AX,2513h ;set interrupt vector mov DX,offset bdisk ;Disk int DOS_CALL ; ; Set LPTx up as the new int 21h interrupt handler ; mov AX,2521h ;set interrupt vector ; mov DX,offset int_21h ;DOS Functions ; int DOS_CALL ; ; Set LPTx up as the new int 28h interrupt handler mov AX,2528h ;set interrupt vector mov DX,offset int_28h ;Idle int DOS_CALL ; ; get the address of the critical section flag ; mov AH,34h int DOS_CALL ;Call Special DOS interrupt ;returns pointer to critical ;section flag in ES:BX ;With DOS 2.1, this returns ;00EC:012D. I used the XRAY ;program to look at this ;byte while DOS was running. mov csect_seg,ES ;save the pointer mov csect_off,BX ; ; get the address of the critical error flag. This piece of code comes from ; PC Magazine, October 13, 1987, page 416, CARDFILE.ASM, by Jeff Prosise. ; mov cerrf_seg,ES ;save the pointer for critical error mov ax,3E80h ;CMP opcode mov cx,2000h ;max search length mov di,bx ;start at critical section address ce_init4: repne scasw ;do the search jcxz ce_init5 ;branch if search failed cmp byte ptr es:[di+5],0BCh ;verify this is it je ce_found ;branch if it is jmp ce_init4 ;resume loop if it's not ce_init5: mov cx,2000h ;search again inc bx ;search odd addresses this time mov di,bx ce_init6: repne scasw ;look for the opcode jcxz ce_notfound ;not found if loop expires cmp byte ptr es:[di+5],0BCh ;verify this is it je ce_found jmp ce_init6 ce_notfound: mov ax,csect_off ;flag not found, fake it jmp ce_end ce_found: mov ax,es:[di] ;get flag offset address ce_end: mov cerrf_off,ax ;save it ; pop BX pop ES display lptx_resident ;resident loaded message call stat ;display status mov DX,offset end_res int 27h ;terminate but stay resident ; ; Normal exit for transient copy of LPTx nor_exit: call stat ;display status bail_out: mov AH,0 int DOS_CALL ;terminate ; ; [-i] ; unhook LPTx from interrupt vectors 08h, 09h, 17h, 21h, and 28h inactivate: ; cmp word ptr ES:old_17h,0 ;is it sill 0? je bail_out ;yes, we weren't installed yet ; flush all buffers mov BX,offset lpt1 cmp ES:[BX].active,ON ;are we active? jne no_cl1 ;no mov AL,1AH ;CTRL-Z push DS push ES pop DS ;set DS to point to resident ;data segment ; call prnt ;print end of file mark call flush pop DS ;restore DS mov ES:[BX].active,OFF ;make us inactive display lptx_off ;capturing off message ; no_cl1: mov BX,offset lpt2 cmp ES:[BX].active,ON ;are we active? jne no_cl2 ;no mov AL,1AH ;CTRL-Z push DS push ES pop DS ;set DS to point to resident ;data segment ; call prnt ;print end of file mark call flush pop DS ;restore DS mov ES:[BX].active,OFF ;make us inactive display lptx_off ;capturing off message ; no_cl2: mov BX,offset lpt3 cmp ES:[BX].active,ON ;are we active? jne no_cl3 ;no mov AL,1AH ;CTRL-Z push DS push ES pop DS ;set DS to point to resident ;data segment ; call prnt ;print end of file mark call flush pop DS ;restore DS mov ES:[BX].active,OFF ;make us inactive display lptx_off ;capturing off message no_cl3: push DS mov DX,word ptr ES:old_17h ;original vector, offset mov AX,word ptr ES:old_17h[2];original vector, segment mov DS,AX mov AX,2517h ;set interrupt vector to DS:DX int DOS_CALL pop DS push DS mov DX,word ptr ES:old_21h ;original vector, offset mov AX,word ptr ES:old_21h[2];original vector, segment mov DS,AX mov AX,2521h ;set interrupt vector to DS:DX int DOS_CALL pop DS push DS mov DX,word ptr ES:old_08h ;original vector, offset mov AX,word ptr ES:old_08h[2];original vector, segment mov DS,AX mov AX,2508h ;set interrupt vector to DS:DX int DOS_CALL pop DS push DS mov DX,word ptr ES:old_09h ;original vector, offset mov AX,word ptr ES:old_09h[2] ;original vector, segment mov DS,AX mov AX,2509h ;set interrupt vector to DS:DX int DOS_CALL pop DS push DS mov DX,word ptr ES:old_10h ;original vector, offset mov AX,word ptr ES:old_10h[2] ;original vector, segment mov DS,AX mov AX,2510h ;set interrupt vector to DS:DX int DOS_CALL pop DS push DS mov DX,word ptr ES:old_13h ;original vector, offset mov AX,word ptr ES:old_13h[2] ;original vector, segment mov DS,AX mov AX,2513h ;set interrupt vector to DS:DX int DOS_CALL pop DS push DS mov DX,word ptr ES:old_28h ;original vector, offset mov AX,word ptr ES:old_28h[2];original vector, segment mov DS,AX mov AX,2528h ;set interrupt vector to DS:DX int DOS_CALL pop DS display lptx_gone ;inactivated jmp bail_out ;------------------------------------------------------------------------ ; ; displays the status of each of the three line printers ; stat proc near ; display each LPTx with a message "not redirected" ; or redirected to <filename> push AX push BX push DX push SI push DI display stat_stat stat_1: mov BX,offset lpt1 ;first printer mov stat_ptr,'1' display stat_lp cmp ES:[BX].active,ON ;are we active? je stat_1_a ;yes display stat_off jmp short stat_2 stat_1_a: mov SI,BX ;base add SI,offset lpt1.filen ;offset mov DI,offset stat_fn stat_1_lp: mov AL,ES:[SI] mov [DI],AL inc SI inc DI cmp AL,NULL ;loop till a null byte is found jne stat_1_lp mov byte ptr [DI],CR inc DI mov byte ptr [DI],LF inc DI mov byte ptr [DI],DOLLAR display stat_dir ;display file name stat_2: mov BX,offset lpt2 ;second printer mov stat_ptr,'2' display stat_lp cmp ES:[BX].active,ON ;are we active? je stat_2_a ;yes display stat_off jmp short stat_3 stat_2_a: mov SI,BX ;base add SI,offset lpt1.filen ;offset mov DI,offset stat_fn stat_2_lp: mov AL,ES:[SI] mov [DI],AL inc SI inc DI cmp AL,NULL ;loop till a null byte is found jne stat_2_lp mov byte ptr [DI],CR inc DI mov byte ptr [DI],LF inc DI mov byte ptr [DI],DOLLAR display stat_dir ;display file name stat_3: mov BX,offset lpt3 ;third printer mov stat_ptr,'3' display stat_lp cmp ES:[BX].active,ON ;are we active? je stat_3_a ;yes display stat_off jmp short stat_done stat_3_a: mov SI,BX ;base add SI,offset lpt1.filen ;offset mov DI,offset stat_fn stat_3_lp: mov AL,ES:[SI] mov [DI],AL inc SI inc DI cmp AL,NULL ;loop till a null byte is found jne stat_3_lp mov byte ptr [DI],CR inc DI mov byte ptr [DI],LF inc DI mov byte ptr [DI],DOLLAR display stat_dir ;display file name stat_done: pop DI pop SI pop DX pop BX pop AX ret stat endp ; cseg ends %out EOF end lptx