Computer Select (Limited Edition)

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Assembly Source File | 1992-01-27 | 75.4 KB | 2,182 lines

page 66,132 ;============================================================================ ; ADDIT.COM adds a series of numbers captured from the display. ; ; Usage: ADDIT [/B][/U] ; ; B = Use Video BIOS calls ; U = Uninstall ; ; Revision History: ; ; Version 1.0 Initial Release ; Version 1.1 Bug fix ; ;============================================================================ POPTIME equ 9 ;Allow 1/2 second to popup STACKSIZE equ 512 ;TSR stack MSGBOX_BUFFSIZE equ 1 * 132 * 2 ;Screen save buff for title HELPBOX_BUFFSIZE equ 5 * 132 * 2 ;Screen save buff for help MSGBOX_BUFFER equ offset end_of_resident ATTR_BUFFER equ MSGBOX_BUFFER + MSGBOX_BUFFSIZE ;---------------------------------------------------------------------------- ; BIOS Data segment ;---------------------------------------------------------------------------- bios_data segment at 40h org 17h shift_state db ? ;State of keyboard shift keys org 1Ah keybuff_head dw ? ;Start ptr for keyboard buff keybuff_tail dw ? ;End ptr for keyboard buff org 4Eh video_buffoff dw ? ;Offset of video buffer org 63h video_ioregs dw ? ;I/O addr of video controller org 80h keybuff_start dw ? ;Start ptr for keyboard buff keybuff_end dw ? ;End ptr for keyboard buff video_rows db ? ;Number of rows on the screen bios_data ends ;---------------------------------------------------------------------------- ; ADDIT Code and Data segments ;---------------------------------------------------------------------------- code segment assume cs:code org 2ch env_segment dw ? ;Word containing the segment ; of the program's env. block. org 80h command_tail db ? ;Offset of the command tail. org 100h prog: jmp initialize ;--------------------------------------------------------------------------- pushf ; Resident Data ;--------------------------------------------------------------------------- pushf program db 13,10 program1 db "ADDIT 1.1 " copyright db "Copyright (c) 1992 Douglas Boling" program2 db 10,13 db "First published in PC Magazine, Feburary 11, 1992" db 13,10,"$",1Ah def_marked_bw db 70h ;Default marked attr B/W def_text_bw db 70h ;Default text attr B/W def_number_bw db 79h ;Default number attr B/W def_neg_bw db 7Fh ;Default neg number attr B/W bw_segment dw 0B000h ;Segment of B/W video memory def_marked_clr db 70h ;Default marked attr Color def_text_clr db 71h ;Default text attr Color def_number_clr db 7Eh ;Default number attr Color def_neg_clr db 74h ;Default neg number attr Color clr_segment dw 0B800h ;Segment of color video memory attr_buffsize dw 1024 ;Size of attribute buffer helpbox_buff dw 0 ;Pointer to helpbox buffer res_stack dw 0 ;Stack ptr when resident indos_ptr dd -1 ;Pointer to INDOS flag criterr_ptr dd -1 ;Pointer to DOS crit err flag int08h dd -1 ;Int 2f vector (Timer) int09h dd -1 ;Int 09 vector (Keyboard HW) int10h dd -1 ;Int 10 vector (Video BIOS) int13h dd -1 ;Int 13 vector (Disk BIOS) int28h dd -1 ;Int 28 vector (DOS Idle) int2Fh dd -1 ;Int 2F vector (DOS Multiplex) int08_active db 0 ;Interrupt active flag int09_active db 0 ;Interrupt active flag int10_active db 0 ;Interrupt active flag int13_active db 0 ;Interrupt active flag int28_active db 0 ;Interrupt active flag int2F_active db 0 ;Interrupt active flag main_active db 0 ;TSR active flag saved_ss dw 0 saved_sp dw 0 hotshift db 0ah ;Shift condition for popup popflag db 0 ;Go active counter keycodes db 3bh,4eh,0dh,51h,49h,4fh,47h,48h,50h,74h,73h,4bh,4dh keycodes_end = $ keyjmp_table dw offset cursor_rt ;Index into key routines are dw offset cursor_lt ; inverse of order of dw offset cursor_clt ; keycode array. dw offset cursor_crt dw offset cursor_dn dw offset cursor_up dw offset cursor_home ;Home dw offset cursor_end ;End dw offset cursor_top ;Page Up dw offset cursor_bottom ;Page Down dw offset addmarked ;=/+ key dw offset addmarked ;keypad + dw offset showhelp ;F1 addmarked_tbl dw offset add_digit ;Digit after digit dw offset setdec ;Period after digit dw offset chkcomma ;Comma after digit dw offset setneg ;Dash after digit dw offset termnumber ;Char after digit dw offset add_digit ;Digit after char dw offset setdec ;Period after char dw offset termnumber ;Comma after char dw offset setneg1 ;Dash after char dw offset termnumber ;Char after char summsg db "Sum:",0 pastemsg db "Number too long to paste",0 helptag db "F1 for Help",0 no_help db 0 ;Blocks help msg ; 1234567891123456789212345678931234567894 helpmsg1 db " <Cursor> keys delete box/move cursor " db " <Shift><Cursor> keys size box",0 helpmsg2 db " <Home> Move to start of line " db " <End> Move to end of line",0 helpmsg3 db " <Pg Up> Move to top of screen " db " <Pg Dn> Move to bot of screen",0 helpmsg4 db " <+> Add numbers found in box " db " <P> Paste sum into application",0 helpmsg5 db " <Esc> Exit the program",0 overflowmsg db "Overflow",0 ; ;Screen variables ; BIOSFlag db 0 ;1 = Use Vid BIOS calls video_ptr label dword video_offset dw 0 ;Offset of video memory video_seg dw 0 ;Segment of video memory marked_attr db 0 ;Screen attr for marked area text_attr db 0 ;Attribute for msg box text number_attr db 0 ;Attribute to mark numbers negative_attr db 0 ;Attribute to mark neg numbers cursor_pos dw 0 ;Cursor position at popup cursor_type dw 0 ;Cursor shape at popup screen_page db 0 ;Active video page screen_size label word screen_cx db 0 ;Screen columns screen_cy db 0 ;Screen rows marked_pos1 label word marked_x1 db 0 ;Marked area starting column marked_y1 db 0 ;marked area starting row marked_pos2 label word marked_x2 db 0 ;Marked area ending column marked_y2 db 0 ;marked area ending row oldmarked_pos1 label word oldmarked_x1 db 0 ;Marked area starting row oldmarked_y1 db 0 ;marked area starting column oldmarked_pos2 label word oldmarked_x2 db 0 ;Marked area columns oldmarked_y2 db 0 ;marked area rows boxactive db 0 ;Flag for message box ; ;Variables used in the addition routines. ; base dw 10 ;base 10 sum_num dw 3 dup (0) sum_exp db 0 sum_sign db 0 curr_num dw 3 dup (0) curr_exp db 0 curr_sign db 0 sum_overflow db 0 decimal_flag db 0 curr_num_active db 0 last_char db 0 ;============================================================================ ; VIDEOINT processes BIOS video services interrupt (Int 10h) ;============================================================================ videoint proc far assume cs:code,ds:nothing,es:nothing inc cs:int10_active pushf call cs:[int10h] ;Call old int dec cs:int10_active iret ;Return videoint endp ;============================================================================ ; DISKINT processes BIOS disk services interrupt (Int 13h) ;============================================================================ diskint proc far assume cs:code,ds:nothing,es:nothing inc cs:int13_active pushf call cs:[int13h] ;Call old int pushf dec cs:int13_active popf ret 2 ;Return preserving flags diskint endp ;============================================================================ ; TIMERINT processes timer interrupt (Int 08h) ;============================================================================ timerint proc far assume cs:code,ds:nothing,es:nothing pushf call cs:[int08h] ;Call old int 8 push ds push cs pop ds assume ds:code cmp int08_active,0 ;See if we are in this jne timerint_exit1 ; routine already inc int08_active cmp popflag,0 ;See if we need to try to jne timer_check ; pop up timerint_exit: dec int08_active timerint_exit1: pop ds iret ;Return timer_check: push ax call check_system ;See if system OK to pop up or ax,ax je timerint_1 or ah,ah je timerint_dec push ax push bx mov ax,0e07h mov bx,0 int 10h pop bx pop ax jmp timerint_dec timerint_1: call main ;Call the TSR mov popflag,1 timerint_dec: dec popflag pop ax jmp short timerint_exit timerint endp ;============================================================================ ; KEYINT processes keyboard interrupts (Int 09h) ;============================================================================ keyint proc far assume cs:code,ds:nothing,es:nothing pushf call cs:[int09h] ;Call old int 9 push ax push ds mov ax,40h mov ds,ax ;Set ES to bios data segment assume ds:bios_data mov al,ds:[shift_state] and al,0fh ;Mask lock bits cmp al,cs:[hotshift] pop ds pop ax je keyint_hotkey keyint_exit: iret ;Return keyint_hotkey: mov cs:popflag,POPTIME ;Set timer to pop up jmp short keyint_exit keyint endp ;============================================================================ ; IDLEINT processes DOS Idle interrupt (Int 28h) ;============================================================================ idleint proc far assume cs:code,ds:nothing,es:nothing pushf call cs:[int28h] ;Call old int push ds push cs pop ds assume ds:code cmp int28_active,0 ;See if we are in this jne idleint_exit1 ; routine already inc int28_active ;Set int active flag cmp popflag,0 ;See if we need to try to jne idle_check ; pop up idleint_exit: dec int28_active ;Set int active flag idleint_exit1: pop ds iret ;Return idle_check: push ax call check_system ;See if OK to pop up. Ignore or al,al ; INDOS since in idle. jne idleint_1 mov popflag,0 ;Clear popup flag call main ;Call the TSR idleint_1: pop ax jmp short idleint_exit idleint endp ;--------------------------------------------------------------------------- pushf ; Check System Determines if the system is in a state compatible with TSRs ; Exit: AL - ORed flags for DOS Idle OK ; AH - State of INDOS flag ;--------------------------------------------------------------------------- pushf check_system proc near assume cs:code,ds:code,es:nothing push bx push ds xor ax,ax or al,int10_active ;Check BIOS video int or al,int13_active ;Check BIOS disk int ; or al,int16_active ;Check BIOS keyboard int lds bx,criterr_ptr ;Check DOS critical error or al,byte ptr ds:[bx] ; flag. lds bx,cs:indos_ptr ;Check INDOS flag mov ah,byte ptr ds:[bx] check_sys_exit: pop ds pop bx ret check_system endp ;============================================================================ ; MAIN this is the main body of the TSR ;============================================================================ main proc near assume cs:code,ds:code,es:nothing cmp main_active,0 ;See if already active jne main_exit cli inc main_active mov [saved_sp],sp ;Save old stack pointer mov [saved_ss],ss mov ax,cs ;Set ss:sp to internal stack mov ss,ax mov sp,res_stack sti ;Enable interrupts cld ;Set string direction UP push bx push cx push dx push di push si push bp push es mov ah,0fh ;Get display mode int 10h cmp al,7 je main_1 ;Pop up only if in text mode. cmp al,4 jb main_1 main_exit1: pop es pop bp pop si pop di pop dx pop cx pop bx cli mov ss,[saved_ss] ;Restore old stack mov sp,[saved_sp] dec main_active main_exit: ret main_1: mov byte ptr no_help,0 ;Enable help message cmp ah,80 jb main_exit1 mov screen_page,bh ;Save active video page mov screen_cx,ah ;Save screen columns mov ah,3 ;Get cursor position int 10h mov cursor_pos,dx ;Save cursor information mov cursor_type,cx cmp dh,0 ;If on top line, move down 1 jne main_11 ; to miss banner. inc dh main_11: mov marked_pos1,dx ;Save initial cursor position mov ax,40h mov es,ax ;Set ES to bios data segment assume es:bios_data mov ah,12h ;Determine if CGA by checking mov bl,10h ; for EGA compatibility int 10h mov al,24 ;CGA, only 25 rows on screen cmp bl,10h je main_2 mov al,es:video_rows ;Get number of rows on screen main_2: mov screen_cy,al ;Save screen rows mov ax,es:video_buffoff ;Copy ptr to video memory mov video_offset,ax mov ax,marked_pos1 ;Copy starting pos to ending mov marked_pos2,ax ; pos to zero block. mov oldmarked_pos1,ax mov oldmarked_pos2,ax test es:video_ioregs,40h ;See if color or monochrome jne main_colorvid mov si,offset def_marked_bw ;Point to B/W parameters jmp short main_3 main_colorvid: mov si,offset def_marked_clr ;Point to color parameters main_3: push ds pop es assume es:code mov di,offset marked_attr ;Copy default attributes movsw movsw lodsw ;Get Video buffer segment mov video_seg,ax mov ah,1 ;Hide the cursor by changing mov cx,200h ; the size of the cursor int 10h call init_attrlist ;Initialize attr save list jc main_end1 mov dx,marked_pos1 ;Mark initial cursor where call getchar ; the old cursor was mov ah,marked_attr ;Mark cursor position on call putchar ; screen. main_loop: cmp boxactive,1 ;If box active, don't reprint je main_4 ; the box. mov al,marked_y2 ;If cursor on top line, don't or al,marked_y2 ; print the title box. je main_4 call msgbox ;Draw title box main_4: call getkey ;Wait for a key cmp al,27 ;If ESC, end. je main_end cmp ah,25 ;If 'p' paste and exit je main_paste mov al,ah ;Copy scan code main_6: mov di,offset keycodes mov cx,offset keycodes_end - offset keycodes repne scasb jne main_loop shl cx,1 ;Convert key num into jump mov bx,cx ; table index. mov ax,marked_pos2 ;Preload parameters into regs mov cx,screen_size ; to save code call [keyjmp_table+bx] ;Call key routine jmp short main_loop main_paste: call paste ;Paste to keyboard buffer main_end: call clearmarked ;Restore attributes call clearbox ;Delete title box main_end1: mov ah,1 ;Set cursor type mov cx,cursor_type mov bh,screen_page int 10h mov ah,2 ;Set cursor position mov dx,cursor_pos int 10h jmp main_exit1 main endp ;----------------------------------------------------------------------------- ; CURSOR KEYS Handles the actions of the cursor keys as the user uses them ; to mark the selected area. ; Entry: AL - marked_x2 ; AH - marked_y2 ; CL - screen_cx ; CH - screen_cy ;----------------------------------------------------------------------------- cursor_keys proc near ; CURSOR HOME Moves the cursor to the left most column cursor_home: xor al,al ;Zero current column jmp short cursor_1 ; CURSOR END Moves the cursor to the right most column cursor_end: mov al,cl ;Set Cur column to screen cols dec al jmp short cursor_1 ; CURSOR TOP Moves the cursor to the top row cursor_top: mov ah,1 ;Move to line 1 to avoid jmp short cursor_1 ; title erase ; CURSOR END Moves the cursor to the bottom row cursor_bottom: mov ah,ch ;Set Cur Row to screen rows jmp short cursor_1 ; CURSOR UP Moves the marked orgin up one row cursor_up: or ah,ah je cursor_1 dec ah jmp short cursor_1 ; CURSOR DN Moves the marked orgin down one row cursor_dn: cmp ah,ch je cursor_1 inc ah jmp short cursor_1 ; CURSOR CLT Moves the marked orgin left 8 columns cursor_clt: sub al,8 jae cursor_1 xor al,al jmp short cursor_1 ; CURSOR CRT Moves the marked orgin right 8 columns cursor_crt: add al,8 dec cl cmp al,cl jb cursor_1 mov al,cl jmp short cursor_1 ; CURSOR LT Moves the marked orgin left one col cursor_lt: or al,al je cursor_1 dec al jmp short cursor_1 ; CURSOR RT Moves the marked orgin right one col cursor_rt: dec cl cmp al,cl jae cursor_1 inc al cursor_1: mov marked_pos2,ax ;Save new position push ax mov ah,2 ;Get shift state int 16h and al,3 pop ax je cursor_11 mov si,offset sum_num ;If changing the size of the call clear_number ; box, clear the sum. inc boxactive jmp short cursor_2 cursor_11: mov marked_pos1,ax ;Not shifted, set points equal cursor_2: or ah,ah ;If cursor on top line, clear jne cursor_3 ; title box so user can see call clearbox ; what is on top line. cursor_3: call drawmarked ret cursor_keys endp ;----------------------------------------------------------------------------- ; PASTE Clears the keyboard buffer, then copys the sum into the buffer. ; Entry: SI - Points to ASCIIZ string to paste into keyboard buffer. ;----------------------------------------------------------------------------- paste proc near push es mov di,offset command_tail ;Point buffer mov si,offset sum_num push di call hex2asc ;Convert sum to ASCII pop si inc si ;Move past attribute mov cx,di ;Compute length of number sub cx,si cmp sum_overflow,0 jne paste_exit mov ax,bios_data mov es,ax assume es:bios_data cli ;No interrupts mov di,es:[keybuff_start] ;Get ptr to buffer offset mov bx,es:[keybuff_end] ;Get ptr to end of buffer push bx sub bx,di shr bx,1 cmp cx,bx pop bx ja paste_overflow sub bx,2 mov es:[keybuff_head],di ;Clear buffer by setting mov es:[keybuff_tail],di ; pointers equal. paste_1: lodsb ;Get character or al,al ;See if end of string je paste_done paste_2: call getscan ;Get scan code for char stosw ;Stuff in keyboard buffer cmp di,bx ;See if buffer full jb paste_1 ;No, continue mov es:[keybuff_tail],di paste_overflow: sti mov si,offset pastemsg ;If number longer than the mov dx,39 ; keyboard buffer print mov ah,negative_attr ; message to warn user. call writestr1 call getkey paste_done: mov es:[keybuff_tail],di sti paste_exit: pop es ret paste endp ;----------------------------------------------------------------------------- ; GETSCAN Returns the keyboard scan code for a limit set of ASCII characters ; Entry: AL - ASCII character ; Exit: AH - Scan code ;----------------------------------------------------------------------------- xlate_keys db 27,"1234567890-,." xlate_keys_end = $ xlate_scan db 52,51,12,11,10,9,8,7,6,5,4,3,2,1 ;Rev of ASCII table getscan proc near push di push es mov cx,cs mov es,cx mov cx,offset xlate_keys_end - offset xlate_keys mov di,offset xlate_keys repne scasb mov di,cx mov ah,[xlate_scan+di] pop es pop di ret getscan endp ;----------------------------------------------------------------------------- ; DRAWMARKED Displays the marked area by changing the screen attributes ; inside the marked area. ;----------------------------------------------------------------------------- drawmarked proc near push es mov ax,marked_pos1 mov dx,marked_pos2 cmp dx,oldmarked_pos2 jne drawmarked_1 cmp ax,oldmarked_pos1 je drawmarked_exit drawmarked_1: mov bx,offset marked_pos1 mov cx,4 drawmarked_2: call find_min ;AX = upper left corner call find_max ;DX = lower right corner add bx,2 loop drawmarked_2 drawmarked_7: sub dx,ax ;Compute size of area xor cx,cx mov cl,dl ;Copy column count mov si,cx inc si mov cl,dh ;Copy row count inc cx mov dx,ax ;Copy starting row, column drawmarked_8: push cx ;Save row count push dx ;Save cursor position mov cx,si ;Get column count drawmarked_9: mov bx,offset marked_pos1 call chk_inwin mov ah,al ;Save in marked area flag mov bx,offset oldmarked_pos1 call chk_inwin cmp ah,al ;See if in or out of both je drawmarked_11 ; areas. If so, no change. push ax ;Save in-window flags call getchar pop bx or bh,bh ;See if in marked area je drawmarked_10 mov ah,marked_attr ;Mark character call putchar jmp short drawmarked_11 drawmarked_10: call get_attr ;Get saved screen attribute call putchar ;Restore attribute drawmarked_11: inc dl loop drawmarked_9 pop dx pop cx inc dh loop drawmarked_8 mov ax,marked_pos1 ;Update old pointers mov oldmarked_pos1,ax mov ax,marked_pos2 mov oldmarked_pos2,ax drawmarked_exit: pop es ret drawmarked endp ;----------------------------------------------------------------------------- ; CLEARMARKED Restores the marked area to its original screen attributes ;----------------------------------------------------------------------------- clearmarked proc near assume ds:code mov bx,offset marked_pos1 call compute_box sub ax,dx xor cx,cx mov cl,al mov si,cx ;Save column count inc si mov cl,ah inc cx clearmarked_3: push cx push dx mov cx,si clearmarked_4: call getchar call get_attr ;Get saved screen attribute call putchar inc dl loop clearmarked_4 pop dx pop cx inc dh loop clearmarked_3 clearmarked_exit: ret clearmarked endp ;----------------------------------------------------------------------------- ; ADDMARKED Finds numbers in marked area, marks them, then sums them. ;----------------------------------------------------------------------------- addmarked proc near assume ds:code mov si,offset sum_num ;Zero sum call clear_number mov di,si mov si,offset curr_num ;Zero current number call clear_number xor al,al mov decimal_flag,al ;Zero other flags mov sum_overflow,al mov curr_sign,al mov curr_num_active,al mov bx,offset marked_pos1 ;Compute dim of marked box call compute_box sub ax,dx ;Compute size of box xor cx,cx mov cl,al inc cx mov bp,cx ;BP = column count mov cl,ah inc cx ;CX = row count addmarked_loop1: push cx push dx mov cx,bp ;Get column count addmarked_loop2: push cx call getchar ;Read char from screen call isnum ;See if character is a number mov bl,ch mov bh,ch xchg last_char,bh ;Change routine called or bh,bh ; depending on if the je addmarked_3 ; pervious char was a digit. add bl,5 addmarked_3: xor bh,bh shl bx,1 push ax call [addmarked_tbl+bx] pop ax cmp curr_num_active,0 ;See if we need to mark the je addmarked_4 ; character call marknum addmarked_4: pop cx inc dl ;Inc Column loop addmarked_loop2 call termnumber ;Number ends at boundry pop dx pop cx inc dh ;Inc Row loop addmarked_loop1 inc boxactive ;Force box to be redrawn addmarked_exit: ret addmarked endp ;----------------------------------------------------------------------------- ; ADDDIGIT Adds digit to current number ; Entry: SI - Pointer to current number ; DI - Pointer to sum number ;----------------------------------------------------------------------------- add_digit proc near mov bl,decimal_flag ;If sign or fraction flags set add bl,curr_sign ; back up to mark the leading je add_digit_1 ; characters call markprev ;Mark preceding char add_digit_1: inc curr_num_active ;Digit found mov bx,base call mul_number ;Multiply number by BASE jo add_digit_3 cmp decimal_flag,0 ;If in fraction, inc exponent je add_digit_2 inc curr_exp add_digit_2: add [si],cx ;Add new digit to number adc word ptr [si+2],0 adc word ptr [si+4],0 jno short add_digit_exit add_digit_3: inc sum_overflow ;Set overflow flag add_digit_exit: ret add_digit endp ;----------------------------------------------------------------------------- ; SETDEC Process decimal point after character ; Entry: SI - Pointer to current number ; DI - Pointer to sum number ;----------------------------------------------------------------------------- setdec proc near cmp decimal_flag,0 ;If decimal flag already found je setdec_1 ; the period terminates the call termnumber ; current number. jmp short setdec_exit setdec_1: mov decimal_flag,1 ; current number. setdec_exit: ret setdec endp ;----------------------------------------------------------------------------- ; CHKCOMMA Process commas ; Entry: SI - Pointer to current number ; DI - Pointer to sum number ;----------------------------------------------------------------------------- chkcomma proc near cmp decimal_flag,0 ;If decimal flag already found je chkcomma_exit ; the comma terminates the call termnumber ; current number. chkcomma_exit: ret chkcomma endp ;----------------------------------------------------------------------------- ; SETNEG Process dash after character ;----------------------------------------------------------------------------- setneg proc near call termnumber ;If num active, terminate it setneg1: mov curr_sign,1 ;Set sign bit. ret setneg endp ;----------------------------------------------------------------------------- ; TERMNUMBER Process character after character ; Entry: SI - Pointer to current number ; DI - Pointer to sum number ;----------------------------------------------------------------------------- termnumber proc near cmp curr_num_active,0 ;See if a number is active je termnum_clear push di ;Save original pointers push si mov al,[di+6] ;Get destination exponent sub al,[si+6] ;Compare to source exponent je termnum_2 ;If equal power, skip shift. ja termnum_1 ;If dest exp less, shift xchg si,di ; destination instead of neg al ; the source. termnum_1: add [si+6],al ;Change exponent xor ah,ah mov cx,ax mov bx,base termnum_11: call mul_number ;Mul number by the base jo termnum_2 ; raised to the power of the loop termnum_11 ; of the exponent. termnum_2: pop si ;Restore original pointers pop di jo termnum_overflow call add_number ;Add numbers together jno termnum_3 termnum_overflow: inc sum_overflow ;Set overflow flag termnum_3: call clear_number ;Zero current number termnum_clear: xor al,al mov curr_num_active,al ;Terminate number mov decimal_flag,al ;Zero fraction flag mov curr_sign,al ;Clear sign termnum_exit: ret termnumber endp ;----------------------------------------------------------------------------- ; ISNUM - Determines if a character is a number, a break character, or a ; character to be ignored ; Entry: AL - character ; Exit: CL - Number, if character is a number ; CH - 0 if number, 1 if decimal point, 2 if comma, 3 if a dash, ; 4 if anything else. ;----------------------------------------------------------------------------- isnum proc near mov ch,3 ;Use AH as char type flag mov cl,al cmp cl,'-' ;Is char a dash? je isnum_1 dec ch cmp cl,',' ;Is char a comma? je isnum_1 dec ch cmp cl,'.' ;Is char a decimal point? je isnum_1 dec ch sub cl,'0' ;Convert char to number jb isnum_no cmp cl,9 ja isnum_no isnum_1: clc isnum_exit: ret isnum_no: mov ch,4 jmp short isnum_exit isnum endp ;----------------------------------------------------------------------------- ; MARKNUM - Sets the attribute of a number on the screen ; Entry: AL - character on screen ; DH,DL - Current row/column ;----------------------------------------------------------------------------- marknum proc near mov ah,number_attr ;Change attribute to indicate cmp curr_sign,0 ; that a number has been je marknum_1 ; found. mov ah,negative_attr marknum_1: call putchar ;Write attribute ret marknum endp ;----------------------------------------------------------------------------- ; MARKPREV - Sets the attribute of the character before the current char ; Entry: BL - Number of prev characters to mark ; DH,DL - Current row/column ;----------------------------------------------------------------------------- markprev proc near dec dl ;Back up and read prev char dec bl ;Recursively call markprev je markprev_1 ; to mark the proper number call markprev ; of characters. markprev_1: push ax call getchar call marknum ;Mark char inc dl ;Go back to original char pop ax ret markprev endp ;----------------------------------------------------------------------------- ; MULNUMBER - Multiplys a number pointed to by SI by the number in BX ; Entry: SI pointer to number ; BX number ; Exit: OF - set if overflow ;----------------------------------------------------------------------------- mul_number proc near push ax push dx mov ax,[si+4] imul bx ;Mul upper word jo mulnum_exit mov [si+4],ax mov ax,[si+2] mul bx ;Mul mid word add [si+4],dx jo mulnum_overflow mov [si+2],ax mov ax,[si] mul bx ;Mul lower word add [si+2],dx adc word ptr [si+4],0 jo mulnum_overflow mov [si],ax clc mulnum_exit: pop dx pop ax ret mulnum_overflow: stc jmp short mulnum_exit mul_number endp ;----------------------------------------------------------------------------- ; ADDNUMBER - Adds two numbers pointed to by SI and DI ; Entry: SI pointer to first number ; DI pointer to second number ; Exit: OF - set if overflow ;----------------------------------------------------------------------------- add_number proc near cmp curr_sign,0 ;If the source is negitive, je addnum_1 ; 2's compliment the number. call neg_number addnum_1: push si lodsw ;Get low source word add [di],ax ;Add to dest low word lodsw ;Get mid source word adc [di+2],ax lodsw ;Get high source word adc [di+4],ax ;Add to dest high word pop si ret add_number endp ;----------------------------------------------------------------------------- ; NEGNUMBER - Performs a two'w compliment on the number ; Entry: SI pointer to number structure ;----------------------------------------------------------------------------- neg_number proc near not word ptr [si] ;2's compliment the number not word ptr [si+2] not word ptr [si+4] xor ax,ax stc adc word ptr [si],ax adc word ptr [si+2],ax adc word ptr [si+4],ax ret neg_number endp ;----------------------------------------------------------------------------- ; CLRNUMBER - Clears the a number ; Entry: SI pointer to number structure ;----------------------------------------------------------------------------- clear_number proc near push ax push di mov di,si xor ax,ax stosw ;Clear low word stosw ;Clear mid word stosw ;Clear high word stosw ;Clear flags pop di pop ax ret clear_number endp ;----------------------------------------------------------------------------- ; GET ATTR Gets a saved attribute in the attribute buffer for a given ; cursor location. ; Entry: DX - Row, Column of character ; Exit: AH - Attribute ;----------------------------------------------------------------------------- get_attr proc near push cx push dx push si push ax call compute_offset ;Get count into buffer mov si,ATTR_BUFFER xor ax,ax mov dx,ax get_attr_1: lodsb ;Get count byte inc si or al,al je get_attr_exit sub cx,ax jae get_attr_1 mov dh,[si-1] ;Get attribute get_attr_exit: pop ax mov ah,dh ;Copy attribute pop si pop dx pop cx ret get_attr endp ;----------------------------------------------------------------------------- ; INIT ATTRLIST Initializes the attribute list ;----------------------------------------------------------------------------- init_attrlist proc near assume ds:code mov bx,screen_size ;Get size of screen inc bh inc bh xor ax,ax mov dx,ax ;Start at top left corner mov cx,ax xchg bh,cl ;CX-Col count, BX-Row cnt mov si,bx mov di,ATTR_BUFFER ;Get pointer to buffer call getchar mov bh,ah mov bl,0 init_attrlist_1: push cx push dx mov cx,si ;Get number of columns init_attrlist_2: call getchar ;Read attribute cmp bh,ah ;Compare attributes jne init_attrlist_newblk ;If different write block inc bl ;Incriment count cmp bl,-1 ;If count full, write block je init_attrlist_newblk mov bh,ah ;Copy attribute value init_attrlist_3: inc dl ;Next column loop init_attrlist_2 pop dx pop cx inc dh ;Next row loop init_attrlist_1 clc init_attrlist_exit: ret init_attrlist_newblk: mov ds:[di],bx ;Write old block to list inc di ;Update ptr inc di mov bl,1 ;New count mov bh,ah ;Copy new attribute cmp di,helpbox_buff jb init_attrlist_3 ;If list runs into the help inc no_help ; buffer, disable help push ax mov ax,helpbox_buff ;If past helpbox buffer, exit add ax,HELPBOX_BUFFSIZE cmp di,ax pop ax jb init_attrlist_3 ;If list past help box stc ; buffer, exit prog. jmp short init_attrlist_exit init_attrlist endp ;----------------------------------------------------------------------------- ; COMPUTE OFFSET Computes the offset into the attribute buffer for a ; given cursor location. ; Entry: DX - Row, Column of character ; Exit: CX - Offset in buffer. ;----------------------------------------------------------------------------- compute_offset proc near push ax push dx mov al,dh ;Copy column mul screen_cx ;Mul by width of screen xor dh,dh add ax,dx ;Add row xchg cx,ax pop dx pop ax ret compute_offset endp ;----------------------------------------------------------------------------- ; CHK INWIN Determines if a character is inside the bounds of an area ; Entry: BX - Pointer to bounding rectangle ; x1 db point 1 column ; y1 db point 1 row ; x2 db point 2 column ; y2 db point 2 row ; DX - Row, Column of character ; Exit: AL - <> 0 if inside area ;----------------------------------------------------------------------------- chk_inwin proc near push bx push cx push ax ;Save AX push dx ;Save current cursor pos call compute_box ;DX = UL corner, AX = LR corner pop bx xchg bx,dx ;DX = cur cursor, BX=UL corner mov cx,ax ;CX = LR corner pop ax ;Restore AX mov al,0 ;Clear inbox flag cmp dl,bl ;See if above starting row jb chk_inwin_exit cmp dh,bh ;See if left of starting col jb chk_inwin_exit cmp dl,cl ;See if below ending row ja chk_inwin_exit cmp dh,ch ;See if right of ending col ja chk_inwin_exit inc al chk_inwin_exit: pop cx pop bx ret chk_inwin endp ;----------------------------------------------------------------------------- ; FIND MIN Computes the smaller of two screen coordinates. ; Entry: AX - Row, Column of 1st coordinate ; BX - Pointer to 2nd coordinate ; Exit: AX - Result coordinate. ;----------------------------------------------------------------------------- find_min proc near cmp al,[bx] jbe find_min_1 mov al,[bx] find_min_1: cmp ah,[bx+1] jbe find_min_2 mov ah,[bx+1] find_min_2: ret find_min endp ;----------------------------------------------------------------------------- ; FIND MAX Computes the larger of two screen coordinates. ; Entry: DX - Row, Column of 1st coordinate ; BX - Pointer to 2nd coordinate ; Exit: AX - Result coordinate. ;----------------------------------------------------------------------------- find_max proc near cmp dl,[bx] jae find_max_1 mov dl,[bx] find_max_1: cmp dh,[bx+1] jae find_max_2 mov dh,[bx+1] find_max_2: ret find_max endp ;----------------------------------------------------------------------------- ; COMPUTE BOX Puts the starting row/column in DX and the SI and CX ; Entry: BX - Pointer to coordinates ; Exit: AX - Ending row/column ; DX - Starting row/column ;----------------------------------------------------------------------------- compute_box proc near mov ax,[bx] mov dx,[bx+2] cmp al,dl ja compute_box_1 xchg al,dl compute_box_1: cmp ah,dh ja compute_box_2 xchg ah,dh compute_box_2: ret compute_box endp ;----------------------------------------------------------------------------- ; SHOWHELP Displays a help screen on the first three lines of the display ;----------------------------------------------------------------------------- showhelp proc near cmp byte ptr no_help,0 ;See if help msg disabled. jne showhelp_exit mov dh,1 ;Box at top of screen mov cx,5 mov di,helpbox_buff showhelp_1: push cx call saveline inc dh pop cx loop showhelp_1 mov dh,1 mov si,offset helpmsg1 ;Write help text line call writeline inc dh ;Move to next line mov si,offset helpmsg2 call writeline inc dh ;Move to next line mov si,offset helpmsg3 call writeline inc dh ;Move to next line mov si,offset helpmsg4 call writeline inc dh ;Move to next line mov si,offset helpmsg5 call writeline call getkey ;Wait for a key mov dh,1 ;Box at top of screen mov cx,5 mov si,helpbox_buff showhelp_2: push cx call restoreline inc dh pop cx loop showhelp_2 showhelp_exit: ret showhelp endp ;----------------------------------------------------------------------------- ; MSGBOX displays a message in a text window on the top line of the ; screen. The current data on the screen is saved. ; ; Entry: DS:SI - Pointer to string to display. ;----------------------------------------------------------------------------- msgbox proc near mov dh,0 ;Box at top of screen mov al,boxactive cmp al,2 ;Display sum only je msgbox_1 or al,al ;If box already displayed, jne msgbox_1 ; don't save screen data. mov di,MSGBOX_BUFFER call saveline msgbox_1: mov si,offset program1 mov cx,offset program2 - offset program1 xor dx,dx msgbox_11: lodsb call writechar loop msgbox_11 push dx msgbox_12: mov al,' ' ;Pad line with spaces call writechar cmp dl,screen_cx jb msgbox_12 pop dx add dl,6 mov si,offset summsg call writestr mov dl,screen_cx sub dl,12 mov si,offset helptag call writestr msgbox_2: mov ah,text_attr mov si,offset overflowmsg ;Assume overflow cmp sum_overflow,0 jne msgbox_error mov di,offset command_tail ;Point to num and print mov si,offset sum_num push di call hex2asc ;Convert number to ASCII pop si lodsb ;Get attribute for number mov ah,al msgbox_error: mov dl,44 call writestr1 ;Write number or overflow msgbox_3: mov boxactive,1 ;Set box active flag ret msgbox endp ;----------------------------------------------------------------------------- ; CLEARBOX removes the title box from the screen. ;----------------------------------------------------------------------------- clearbox proc near cmp boxactive,0 ;If box already displayed, je clearbox_2 ; don't save screen data. mov si,MSGBOX_BUFFER mov dh,0 ;Box at top of screen call restoreline mov boxactive,0 ;Clear box displayed flag clearbox_2: ret clearbox endp ;----------------------------------------------------------------------------- ; WRITELINE Writes a line of help text to the screen. The line is padded ; with spaces to the right. ; Entry: DH - Line on screen to write ; SI - Pointer to ASCIIZ text ;----------------------------------------------------------------------------- writeline proc near push dx xor dl,dl ;Start at left side of screen call writestr ;Write string writeline_2: mov al,' ' ;Pad line with spaces call writechar cmp dl,screen_cx jb writeline_2 pop dx ret writeline endp ;----------------------------------------------------------------------------- ; SAVELINE Saves the contents of a screen line ot a buffer ; Entry: DH - Line on screen to save ; DI - Pointer to save buffer ;----------------------------------------------------------------------------- saveline proc near push dx xor dl,dl ;Start at left side of screen xor cx,cx mov cl,screen_cx saveline_1: call getchar ;Read character from screen stosw inc dl ;Point to next character loop saveline_1 pop dx ret saveline endp ;----------------------------------------------------------------------------- ; RESTORELINE Restores the screen that was covered by a line of program ; helptext. ; Entry: DH - Line on screen to restore ; SI - Pointer to buffer that contains original screen contents ;----------------------------------------------------------------------------- restoreline proc near push dx xor dl,dl ;Start at left side of screen xor cx,cx mov cl,screen_cx restoreline_1: lodsw call writechar1 ;Read character from screen loop restoreline_1 pop dx ret restoreline endp ;----------------------------------------------------------------------------- ; WRITESTR Writes a string to the screen. ; Entry: DH,DL - Row/Column to write the string ; SI - Pointer to ASCIIZ text ;----------------------------------------------------------------------------- writestr proc near mov ah,text_attr writestr1: lodsb ;Read text from string, then or al,al ; call putchar to write to je writestr_1 ; the screen. call writechar1 jmp short writestr1 writestr_1: ret writestr endp ;----------------------------------------------------------------------------- ; WRITECHAR Writes a character to the screen ; Entry: AL - Character ; DX - Row, Column ;----------------------------------------------------------------------------- writechar proc near mov ah,text_attr writechar1: call putchar inc dl ret writechar endp ;----------------------------------------------------------------------------- ; HEX2ASC converts number in DX AX to ASCII ; Entry: SI - Pointer to number ; DI - Pointer to buffer to store ASCII number ;----------------------------------------------------------------------------- hex2asc proc near assume ds:code,es:nothing push bx push cx push si push bp push [si] ;Save current number push [si+2] push [si+4] mov al,number_attr ;Save proper attribute stosb test byte ptr [si+5],80h ;See if negative je hex_1 call neg_number ;Negate number dec di mov al,negative_attr ;Change attribute to indicate mov ah,'-' ; negative number, then stosw ; print - sign. hex_1: xor cx,cx ;Clear digit counter hex_loop1: xor bx,bx ;BX used for zero test mov ax,[si+4] ;Get high word xor dx,dx ;Clear high word div base ;Divide by base mov [si+4],ax or bx,ax ;OR quotient for zero test mov ax,[si+2] ;Get mid word div base ;Divide by base mov [si+2],ax or bx,ax ;OR quotient for zero test mov ax,[si] ;Get low word div base ;Divide by base mov [si],ax or bx,ax ;OR quotient for zero test add dl,30h ;Convert to ascii push dx ;Save digit on stack inc cx ;Inc digit count or bx,bx jne hex_loop1 ;If number <> 0, continue. mov bl,"0" ;Set leading zero flag mov bh,3 ;Get comma spacing constant mov bp,cx ;Copy digit count xor ax,ax mov al,[si+6] ;Subtract exponent to get sub bp,ax ; num of non-fraction digits jmp short hex_2 ;Don't lead with a comma hex_loop2: xor ax,ax or ax,bp ;Get number non-fract digits js hex_4 ;If count neg, inside fract div bh ;If digit count a multiple or al,al ; of 3 insert comma. je hex_2 or ah,ah jne hex_2 mov al,',' jmp short hex_3 hex_2: or bp,bp ;If position count zero jne hex_4 ; insert decimal point. mov al,'.' hex_3: stosb ;Copy char to buffer hex_4: pop ax ;Get digit off stack or bl,al ;Don't print leading zeros. cmp bl,"0" ;The first non zero will je hex_5 ; change bl to non-zero. stosb hex_5: dec bp ;Dec current digit count loop hex_loop2 cmp bl,"0" ;If number zero, write last jne hex_exit ; zero. mov al,bl stosb hex_exit: xor al,al ;Terminate with 0 stosb pop [si+4] ;Restore number pop [si+2] pop [si] pop bp pop si pop cx pop bx ret hex2asc endp ;----------------------------------------------------------------------------- ; GETCHAR Reads a character and its attribute from the screen ; Entry: DH - Row of character to read ; DL - Column of character to read ; Exit: AL - Character ; AH - Attribute ;----------------------------------------------------------------------------- getchar proc near push bx cmp BIOSFlag,0 jne getchar_bios push cx push si push ds call compute_offset ;Get offset into buffer shl cx,1 ;Double for char and attr lds si,video_ptr ;Get ptr to video memory add si,cx ;Double since char and attr lodsw ;Read char/attribute pop ds pop si pop cx jmp short getchar_exit getchar_bios: mov ah,2 ;Set cursor mov bh,screen_page int 10h mov ah,8 ;Read character/attr int 10h getchar_exit: pop bx ret getchar endp ;----------------------------------------------------------------------------- ; PUTCHAR Writes a character and its attribute to the screen ; Entry: AL - Character to write ; AH - Attribute to write ; DH - Row of character to write ; DL - Column of character to write ;----------------------------------------------------------------------------- putchar proc near push bx push cx push ax cmp BIOSFlag,0 jne putchar_bios push di push es call compute_offset ;Get offset into buffer shl cx,1 ;Double since char and attr les di,video_ptr add di,cx ;Add to start of buffer stosw ;Read char/attribute pop es pop di jmp short putchar_exit putchar_bios: mov ah,2 ;Set cursor mov bh,screen_page int 10h pop ax push ax mov bl,ah ;Copy attribute mov ah,9 ;Read character/attr mov cx,1 int 10h putchar_exit: pop ax pop cx pop bx ret putchar endp ;----------------------------------------------------------------------------- ; GETKEY Waits for a key from the keyboard. ; Exit: AX - Scan code, ASCII char from keyboard. ;----------------------------------------------------------------------------- getkey proc near mov ah,1 ;Check for key int 16h jnz getkey_exit int 28h ;Call DOS Idle mov ax,1680h ;Release Timeslice int 2fh jmp short getkey getkey_exit: xor ax,ax ;Get key int 16h ret getkey endp even ;Align stack on word boundry end_of_resident = $ ;---------------------------------------------------------------------------- ; Non-resident data. ;---------------------------------------------------------------------------- alrdy_installed db 0 ;Installed flag installed_seg dw 0 ;Segment of installed code dos_version dw 0 ;DOS version patchcode db "AlLs" ShiftCodes db "Rs","Ls","Al","Ct" ;These codes are used by ShiftText db "Ctrl",0 ; PATCH.COM for indicating db "Alt",0 ; Hot Shift combinations. db "Left-Shift",0 db "Right-Shift",0 infomsg2 db "ADDIT uninstalled$" errmsg0 db "Need DOS 3.0 or greater$" errmsg1 db "ADDIT not installed$" errmsg2 db "Usage: ADDIT [/B][/U]",13,10 db "/B = Use Video BIOS",13,10 db "/U = Uninstall",13,10,"$" errmsg3 db "Can",39,"t uninstall$" errmsg4 db "ADDIT already installed$" errmsg5 db "Can not find Critical error flag$" endmsg db 13,10,"$" infomsg1 db "ADDIT installed",13,10,10 db "Hot key is " infomsg1a db "$" ;---------------------------------------------------------------------------- ; Initialization routine. ;---------------------------------------------------------------------------- initialize proc near assume cs:code,ds:code,es:code cld mov dx,offset program ;Print copyright message call printmsgcr mov ah,30h ;Get DOS version int 21h xchg al,ah ;Swap major, minor numbers mov dx,offset errmsg0 ;Bad DOS version cmp ah,3 ;Run if DOS 3.0 or greater. jb disp_error mov dos_version,ax ;Save version number mov ax,offset end_of_code+512 ;Set stack ptr mov sp,ax add ax,15 mov cl,4 ;Convert offset to segment size shr ax,cl mov ah,4ah ;Reduce memory allocation int 21h call find_installed ;See if already installed jc init_1 inc alrdy_installed ;Yes, set flag mov installed_seg,es ;Save seg of installed code init_1: push ds pop es mov dx,offset errmsg4 ;Default message mov di,80h ;Parse command line xor cx,cx or cl,[di] ;Get length of cmd line je init_exit init_2: mov al,'/' repne scasb ;Find command line switches jne init_exit mov al,[di] ;Get comamnd line switch or al,20h cmp al,'b' ;See if Video BIOS parameter jne init_3 inc BIOSFlag jmp short init_2 init_3: cmp al,'u' ;See if uninstall je init_4 mov dx,offset errmsg2 ;Print useage statement ; ;Display error message. ; assume ds:nothing disp_error: push cs pop ds assume ds:code call printmsgcr ;print string mov ax,4c01h ;Terminate with RC = 1 int 21h init_4: call remove ;Remove installed copy jc disp_error jmp short exit init_exit: cmp alrdy_installed,0 jne disp_error call install jc disp_error exit: mov ax,4C00h ;Terminate with RC = 0 int 21h initialize endp ;----------------------------------------------------------------------------- ; INSTALL Installs the program ;----------------------------------------------------------------------------- assume cs:code,ds:code,es:code install proc near mov ah,34h ;Get ptr to INDOS flag int 21h mov word ptr indos_ptr,bx mov word ptr indos_ptr[2],es call findCEF ;Get ptr to crit error flag jc install_error mov word ptr criterr_ptr,bx mov word ptr criterr_ptr[2],es mov al,08h ;Get/set the timer interrupt mov dx,offset timerint mov di,offset int08h call set_interrupt mov al,09h ;Get/set the keyboard int mov dx,offset keyint mov di,offset int09h call set_interrupt mov al,10h ;Get/set the video interrupt mov dx,offset videoint mov di,offset int10h call set_interrupt mov al,13h ;Get/set the disk interrupt mov dx,offset diskint mov di,offset int13h call set_interrupt mov al,28h ;Get/set the DOS idle int mov dx,offset idleint mov di,offset int28h call set_interrupt push cs push cs pop ds assume ds:code pop es assume es:code call setshiftmsg ;Set proper install text mov dx,offset infomsg1 ;Print program installed msg call printmsgcr mov dx,ATTR_BUFFER ;Set pointers for resident add dx,attr_buffsize ; code. mov helpbox_buff,dx add dx,HELPBOX_BUFFSIZE + 512 mov res_stack,dx add dx,15 mov cl,4 shr dx,cl mov ax,3100h ;Terminate and stay resident int 21h install_error: ret install endp ;----------------------------------------------------------------------------- ; REMOVE uninstalls the installed program from memory. ;----------------------------------------------------------------------------- remove proc near assume ds:code,es:code push ds push es mov dx,offset errmsg1 ;Not installed message cmp alrdy_installed,0 je remove_error1 mov ds,installed_seg ;Point DS to installed code assume ds:nothing mov al,8 ;Restore int 8 (Timer) mov dx,offset timerint mov di,offset int08h call restore_int jc remove_error mov al,9 ;Restore int 9 (keyboard) mov dx,offset keyint mov di,offset int09h call restore_int jc remove_error mov al,10h ;Restore int 10h (BIOS Video) mov dx,offset videoint mov di,offset int10h call restore_int jc remove_error mov al,13h ;Restore int 13h (BIOS disk) mov dx,offset diskint mov di,offset int13h call restore_int jc remove_error mov al,28h ;Restore int 28h (DOS Idle) mov dx,offset idleint mov di,offset int28h call restore_int jc remove_error mov es,ds:[2ch] ;Get installed env seg mov ah,49h int 21h ;Free installed env segment push ds pop es mov ah,49h ;Free installed program segment int 21h mov ax,cs mov ds,ax mov es,ax mov dx,offset infomsg2 ;Print program removed msg call printmsgcr clc remove_exit: pop ds pop es ret remove_error: mov dx,offset errmsg3 ;Can't uninstall msg remove_error1: stc jmp short remove_exit remove endp ;----------------------------------------------------------------------------- ; SETINTERRUPT Get and sets an interrupt ; Entry: AL - Interrupt number ; DX - Pointer to new interrupt routine ; DI - Pointer to storage location for old interrupt vector ;----------------------------------------------------------------------------- assume cs:code,ds:code,es:nothing set_interrupt proc near push es push ax mov ah,35h ;DOS get interrupt int 21h pop ax mov word ptr [di],bx ;Save old vector mov word ptr [di+2],es mov ah,25h ;DOS set interrupt int 21h pop es ret set_interrupt endp ;----------------------------------------------------------------------------- ; RESTOREINT Checks to see if an interrupt vector has been changed, if not ; the interrupt vector is restored with its original value ; Entry: AL - Interrupt number ; DS:DX - Pointer to current interrupt routine ; DS:DI - Pointer to old interrupt vector ;----------------------------------------------------------------------------- assume cs:code,ds:nothing restore_int proc near push es push ax mov ah,35h ;DOS get interrupt int 21h pop ax ;Get back interrupt number cmp dx,bx ;Compare routine offset jne restoreint_error mov bx,es ;Get current vector segment mov cx,ds ;Get installed segment cmp cx,bx ;Compare routine segment jne restoreint_error push ds lds dx,ds:[di] ;Get old vector mov ah,25h ;DOS set interrupt int 21h clc pop ds restoreint_exit: pop es ret restoreint_error: stc jmp short restoreint_exit restore_int endp ;----------------------------------------------------------------------------- ; FINDCEF Finds the DOS ErrorMode (Critical error) flag ; Exit: ES:BX - Segment,offset of ErrorMode flag ; CF - Clear if flag found ;----------------------------------------------------------------------------- findCEF proc near mov ah,34h ;Get InDOS address int 21h dec bx cmp dos_version,30ah ;If DOS 3.1 or later, ErrorMode jnc findCEF_exit ; sits before InDOS. mov ax,3e80h ;CMP opcode mov si,028cdh ;Int 28 Opcode mov dl,75h ;JNE Opcode mov cx,-1 ;max search length mov di,bx ;start at INDOS address findCEF_1: repne scasb ;do the search jcxz findCEF_notfound ;branch if search failed cmp es:[di],ah ;Check other half of CMP opcode jne findCEF_1 cmp byte ptr es:[di+4],dl ;Check for JNE jne findCEF_1 cmp word ptr es:[di+6],si ; Check for Int 28h call jne findCEF_1 ;Resume loop if not found inc di mov bx,es:[di] ;Get offset of ErrorMode flag clc findCEF_exit: ret findCEF_notfound: stc mov dx,offset errmsg5 ;Can't find Critical Error flg jmp short findCEF_exit findCEF endp ;----------------------------------------------------------------------------- ; FIND INSTALLED Find the installed code by scanning the memory control blocks. ; Exit: AX - Segment of installed code if found. ; CF - Clear if installed code found ;----------------------------------------------------------------------------- find_installed proc near assume ds:code,es:code mov word ptr prog,0 mov bx,0A000h ;Start at upper mem blk start mov ax,cs ;keep CS value in AX find_installed_1: inc bx ;increment search segment value mov es,bx assume es:nothing cmp ax,bx ;not installed if current je find_installed_2 ; segment is found. call cmpheader jne find_installed_1 ;loop back if not found clc find_installed_exit: ret find_installed_2: stc jmp short find_installed_exit find_installed endp ;----------------------------------------------------------------------------- ; CMPHEADER compares the first 16 bytes of this file with the segment ; pointed to by ES. ; Entry: DS - code segment ; ES - pointer to segment to compare ; Exit: ZF - 0 = segments match. ;----------------------------------------------------------------------------- cmpheader proc near assume ds:code,es:nothing mov si,offset prog ;Search this segment for ASCII mov di,si ; fingerprint. mov cx,16 repe cmpsb ret cmpheader endp ;----------------------------------------------------------------------------- ; SETSHIFTMSG Sets the proper hot shift text from the code set by PATCH.COM ;----------------------------------------------------------------------------- setshiftmsg proc near assume ds:code,es:code mov si,offset infomsg1a mov ax,word ptr patchcode call setshiftmsg1 mov ax,word ptr [patchcode+2] call setshiftmsg1 mov byte ptr [si],'$' ret setshiftmsg endp setshiftmsg1 proc near mov byte ptr [si],'<' inc si mov di,offset shiftcodes ;Scan code list to find mov cx,4 ; the proper shift word repne scasw ; to use in the message jne setshiftmsg_exit mov ah,cl mov di,offset shifttext ;Find message in list xor al,al or ah,ah je setshiftmsg_2 setshiftmsg_1: mov cx,30 repne scasb dec ah jne setshiftmsg_1 setshiftmsg_2: xchg di,si setshiftmsg_3: lodsb ;Copy shift label to msg stosb or al,al jne setshiftmsg_3 mov byte ptr [di-1],'>' ;Append closing > mov si,di setshiftmsg_exit: ret setshiftmsg1 endp ;----------------------------------------------------------------------------- ; PRINTMSG prints the message pointed to by DX to the screen. ; Entry: DX - pointer to ASCII message terminated by $ ;----------------------------------------------------------------------------- printmsg proc near assume ds:nothing,es:nothing push ds push cs pop ds assume ds:code mov ah,9 ;Print message int 21h pop ds ret printmsg endp ;----------------------------------------------------------------------------- ; PRINTMSGCR calls PRINTMSG, then appends a carriage return to the message. ; Entry: DX - pointer to ASCII message terminated by $ ;----------------------------------------------------------------------------- printmsgcr proc near assume ds:nothing,es:nothing push dx call printmsg mov dx,offset endmsg call printmsg pop dx ret printmsgcr endp even end_of_code = $ code ends end prog