Programmer 7500

home *** CD-ROM | disk | FTP | other *** search

/ Programmer 7500 / MAX_PROGRAMMERS.iso / PASCAL / GETFLD.ZIP / GETFLD.ASM next >

Wrap

Assembly Source File | 1987-06-30 | 20.3 KB | 498 lines

CODE SEGMENT BYTE PUBLIC ASSUME CS:CODE PUBLIC GetField ;-------------------------------------------------------------------------- ; Key code equates... ;-------------------------------------------------------------------------- CR equ 13 ; Carraige return Dkey equ 339 ; Delete key code BkSpace equ 8 ; Back-space Escape equ 27 ; Escape code UpArrw equ 328 ; Up Arrow DnArrw equ 336 ; Down Arrow LftArrw equ 331 ; Left Arrow RtArrw equ 333 ; Right Arrow HmKey equ 327 ; Home key EKey equ 335 ; End key CBkKey equ 127 ; Ctrl-Backspace PgUp equ 329 ; Page Up PgDn equ 337 ; Page Down CtrlCR equ 10 ; Ctrl-Enter ;-------------------------------------------------------------------------- ; The following are offsets in the stack for the input parameters: ;-------------------------------------------------------------------------- Fptr equ word ptr [bp-4] FptrB equ byte ptr [bp-4] Opts equ byte ptr [bp-5] TheOpts equ dword ptr [bp+6] ; Options[0] = length of input options UpCnv equ 02h ; Bit #1 = Convert input to Uppercase! AutoX equ 20h ; Bit #6 = Auto exit from field InitVal equ 80h ; Bit #7 = Use initial value of Ibuf ISize equ 10 ; Position of Size variable on stack col equ 12 ; Position of Column value on stack row equ 14 ; Position of Row value on stack Atrib equ 16 ; Position of Attribute to use for field Ibuf equ 18 ; Position of pointer to input buffer Legal equ 22 ; Positon of legal string on stack KeyVal equ 26 ; Position of pointer to return variable ;-------------------------------------------------------------------------- ; Getkey function: ; Return: AX = 0 if no key pressed ; AX = 1..255 if standard key code ; AX = 256.. if function key or cursor control key... ;-------------------------------------------------------------------------- GetField PROC FAR push bp ; save the base pointer mov bp,sp ; point it to the stack push bp ; save new value on stack jmp start GetKey proc near mov bx,0 ;temporary return value mov ah,1 ; check kbd buffer int 16h ; kbd IO interrupt jz GetKey ; keep waiting until key is found mov ah,0 ; else get kbd char int 16h ; kbd io interupt mov bl,al ; put into return register or al,al ; check for extended code jnz GY1 ; skip if not extended code mov bh,1 ; set MSByte for extended code mov bl,ah ; move scan code into bl GY1: mov ax,bx ; set up for return from function ret ; exit module GetKey endp ;-------------------------------------------------------------------------- ; Put out field with attribute specified by user ;-------------------------------------------------------------------------- RevFld proc near mov ax,0920h ; get blank...& write char code mov bh,0 ; set for page 0 mov bl,Atrib[bp] ; get video attribute mov cx,ISize[bp] ; get length of field int 10h ; go do it! ret revfld endp ;-------------------------------------------------------------------------- ; Write a character to the screen... ;-------------------------------------------------------------------------- WChar proc near mov ah,10 ; write character only at current position mov bh,0 ; page 0 of video board! mov cx,1 ; only write one character... int 10h ; video I/O interrupt (write character) inc Fptr ret wchar endp ;-------------------------------------------------------------------------- ; Goto X,Y position (dh = row, dl = column) ;-------------------------------------------------------------------------- GotoXY proc near dec dh ; Adjust row & column for BIOS dec dl ; (0,0) = upper left corner! mov ah,2 ; set cursor function code mov bh,0 ; set for current page! int 10h ; video I/O interrupt ret gotoxy endp ;-------------------------------------------------------------------------- ; Position cursor to Col+Fptr-1,Row ;-------------------------------------------------------------------------- CurPos proc near mov dl,FptrB ; get Field pointer value dec dl ; subtract 1 add dl,Col[bp] ; dl = Fptr+Col-1 mov dh,Row[bp] ; get Row call GotoXY ; position cursor ret ; exit module curpos endp ;-------------------------------------------------------------------------- ; UpCase function: convert a character to its upper-case equivalent - ; if it is a lowercase letter! ;-------------------------------------------------------------------------- UpCase proc near cmp al,'a' ; Check against 'a' jb UE1 ; nope, its below that cmp al,'z' ; check against 'z' ja UE1 ; nope, its above that! xor al,20h ; make it UPPERCASE! UE1: ret ; exit module upcase endp ;-------------------------------------------------------------------------- ; Check for legal characters in input! ;-------------------------------------------------------------------------- LegalCk proc near les di,Legal[bp] ; get address of legal string mov cl,es:[di] ; get length of legal string xor ch,ch ; zero out msb or cl,cl ; check for zero length je LK1 ; exit if no length LK2: inc di ; increment address pointer cmp al,es:[di] ; is character in legal string? loopne LK2 ; repeat until found or end of table LK1: ret ; exit from module legalck endp ;-------------------------------------------------------------------------- ; Home key function ;-------------------------------------------------------------------------- HomeKey proc near mov Fptr,1 ; set Fptr back to start of field ret HomeKey endp ;-------------------------------------------------------------------------- ; End Key function ;-------------------------------------------------------------------------- EndKey proc near les di,Ibuf[bp] ; get address of Ibuf mov al,es:[di] ; get length of Ibuf... inc al ; Plus one! mov FptrB,al ret endkey endp ;-------------------------------------------------------------------------- ; Right Arrow key ;-------------------------------------------------------------------------- RightKey proc near les di,Ibuf[bp] ; get address of Ibuf mov al,es:[di] ; get length of Ibuf inc al ; plus one! cmp FptrB,al ; compare with Fptr? jnb RY1 ; exit module if ok... inc Fptr ; increment Fptr! RY1: ret RightKey endp ;-------------------------------------------------------------------------- ; Left Arrow Key ;-------------------------------------------------------------------------- LeftKey proc near cmp Fptr,1 ; Fptr > 1? jna LY1 ; move left if ok... dec Fptr ; Fptr := Fptr - 1; LY1: ret LeftKey endp ;-------------------------------------------------------------------------- ; Control-Backspace Key ;-------------------------------------------------------------------------- CBackKey proc near call Init ; Erase entire field & start over! ret cbackkey endp ;-------------------------------------------------------------------------- ; String Delete: delete a character from the current position of a string ;-------------------------------------------------------------------------- StrDel proc near les di,Ibuf[bp] ; get input buffer address mov cx,Fptr ; get field pointer cmp cl,es:[di] ; compare Ibuf[0] w/ Fptr ja DY1 ; Fptr > Ibuf[0] je DY2 ; Ibuf[0] = Fptr mov bx,cx ; Fptr < Ibuf[0] mov cl,es:[di] ; get length of Ibuf sub cl,bl ; cx = # of char's to move DYLP1: mov al,es:[di+bx+1] ; get char @ next position mov es:[di+bx],al ; place char @ current position inc bx ; get ready for next char loop DYLP1 ; repeat until cx = 0 DY2: dec byte ptr es:[di] ; decrement Ibuf length by one DY1: ret ; exit from module! strdel endp ;-------------------------------------------------------------------------- ; Screen delete: remove a character from the field shown on the screen! ;-------------------------------------------------------------------------- ScrDel proc near mov ax,row[bp] ; get starting row of field dec ax ; set up for calc mov di,col[bp] ; get starting col of field dec di ; set up for calc add di,Fptr ; add in Fptr offset! dec di ; Col + Fptr - 1 !!! les bx,Ibuf[bp] ; get address of input string mov cl,es:[bx] ; get length of input string xor ch,ch mov bx,0040h ; Calc actual address in video memory... mov es,bx ; set up segment for following: mul es:word ptr[4ah] ; Calc Row * current width add di,ax ; add in # of col's shl di,1 ; multiply by two for Attrib/Value pair mov si,di ; get as source address add si,2 ; next video loc mov dx,es:[63h] ; test video board add dx,6 ; offset of register in video adapter mov ax,0b800h ; Color ? mov bx,es:[10h] ; test for Mono vs Color and bx,30h cmp bx,30h jne setcard ; Board is color... else mov ax,0B000h ; Mono ! setcard: mov es,ax ; set up segment for transfer push ds mov ds,ax sub cx,Fptr ; Calc actual # of char's to move! jb SRExit1 ; if < 0 then skip ... je SRExit2 ; if = 0 then just put out space & exit! test_low: in al,dx ; wait for Horizontal retrace to end test al,1 jnz test_low cli test_hi: in al,dx ; wait for next one to start test al,1 jz test_hi cld ; set direction to forward movelp: movsb ; found it! now move data! inc di inc si loop movelp SREXit2: mov byte ptr ds:[di],' ' ; blank out last position! sti SRExit1: pop ds ret scrdel endp ;-------------------------------------------------------------------------- ; Delete Key ;-------------------------------------------------------------------------- DelKey proc near call ScrDel ; delete char from screen field call StrDel ; delete char from string ret delkey endp ;-------------------------------------------------------------------------- ; Backspace Key ;-------------------------------------------------------------------------- BackKey proc near cmp Fptr,1 ; Fptr > 1? jna BY1 ; move lef if ok dec Fptr ; Fptr := Fptr - 1; call DelKey ; and then delete char!!! BY1: ret BackKey endp ;-------------------------------------------------------------------------- ; This routine accesses all of the key subroutines! ;-------------------------------------------------------------------------- Gosub proc near jmp cx ; jump to address found from table! Gosub endp ;-------------------------------------------------------------------------- ; Test content of AX against entry in JUMP Table! ;-------------------------------------------------------------------------- TabTest2 proc near pop bx ; get address of Table! mov cx,0 ; preset ending value T2Lp1: cmp word ptr cs:[bx],0 ; at end of table? je T2Exit ; yes, get out of subroutine! cmp ax,cs:[bx] ; is char in table entry? jne T2Skip1 mov cx,bx ; get address of match position! add cx,2 ; increment to jump address T2Skip1: add bx,5 ; get to next address! jmp T2Lp1 T2Exit: inc bx inc bx or ch,ch push bx ret ; exit from module! tabtest2 endp ;-------------------------------------------------------------------------- ; Initialize system ;-------------------------------------------------------------------------- Init proc near mov Fptr,1 ; set up Fptr for following... les di,TheOpts mov al,es:[di] mov Opts,al call CurPos ; position cursor to start of field call RevFld ; put out video area test byte ptr Opts,InitVal ; use initial value of Ibuf? jz IT1 ; no, skip setup rtn xor byte ptr Opts,InitVal ; reset flag!! les di,Ibuf[bp] ; get address of Input buffer cmp byte ptr es:[di],0 ; initial value for Ibuf? je IT1 ; no, skip anything else... mov cl,es:[di] ; get length of Ibuf xor ch,ch ; zero out CH IT3: inc di ; increment string pointer mov al,es:[di] ; get byte from Ibuf push cx ; save count! call WChar ; write character to screen call CurPos ; re-position cursor! pop cx ; restore counter loop IT3 ; repeat until message is printed mov Fptr,1 ; reset field pointer to field start les di,Ibuf[bp] ; get address of Input buffer jmp IT2 ; exit from module IT1: mov Fptr,1 ; reset field pointer to field start les di,Ibuf[bp] ; get address of Input buffer mov byte ptr es:[di],0 ; set Input length to zero IT2: ret ; exit module init endp ;-------------------------------------------------------------------------- ; Main module ;-------------------------------------------------------------------------- Main proc near call CurPos ; position cursor call GetKey ; get char from kbd cmp ax,' ' ; is it >= a space? jb MN1 ; not a valid printable character! cmp ax,127 ; is it <= chr(127)? jnb MN1 ; not a valid printable character! test byte ptr Opts,UpCnv ; convert to uppercase option active? jz MN0 ; nope, continue... call UpCase ; else convert it! MN0: call LegalCk ; check for legal character jnz Main ; ignore if not found in legal string mov bl,FptrB ; get current field pointer cmp bl,ISize[bp] ; at end of field? ja Main ; no, skip this test! les di,Ibuf[bp] ; get address of input buffer mov bl,FptrB ; get input pointer value xor bh,bh ; zero out BH mov es:[di+bx],al ; save char into input buffer cmp bl,es:[di] ; increase return size of buffer? jna MN2 ; no, mov es:[di],bl ; yes, store ptr @ buffer length pos MN2: call WChar ; write character to screen mov bl,FptrB ; get current field pointer cmp bl,ISize[bp] ; at end of field? jna Main ; don't worry about it! test byte ptr Opts,AutoX ; auto-exit on? jz Main ; nope - try again mov ax,CR ; pretend to be a CR jmp Skip1 ; go to exit from module MN1: call TabTest2 ; check for address of subroutine... dw EKey ; scan code for [END] key jmp EndKey ; jump to routine dw LftArrw ; scan code for [LEFT ARROW] key jmp LeftKey dw RtArrw ; scan code for [RIGHT ARROW] key jmp RightKey dw CBkKey ; scan code for [^BACKSPACE] jmp CBackKey dw BkSpace ; scan code for [BACKSPACE] jmp BackKey dw HmKey ; scan code for [HOME] key jmp HomeKey dw DKey ; scan code for [DEL] key jmp DelKey dw 0 ; mark end of table jz Skip1 call Gosub ; go do subroutine jmp Main Skip1: ret ; exit from module! main endp ;-------------------------------------------------------------------------- ; Conclusion to program ;-------------------------------------------------------------------------- Conc proc near les di,KeyVal[bp] ; get address of return variable mov es:[di],ax ; store keycode of last keystroke ret ; exit module Conc endp ;-------------------------------------------------------------------------- ; Start of Program !!!! ;-------------------------------------------------------------------------- start: sub sp,5 ; allocate space for locals CmdLoop: call Init ; set up for program call Main ; do main loop call Conc ; conclusion of program pop ax mov sp,bp ; reset stack pointer pop bp ; reset base pointer ret 24 ; exit & clear stack of variables GetField ENDP CODE ENDS END