Power Programmierung 2

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/ Power Programmierung 2 / Power-Programmierung CD 2 (Tewi)(1994).iso / c / library / dos / diverses / cexpress / printer / prtcntr.asm < prev next >

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Assembly Source File | 1989-05-03 | 6.2 KB | 215 lines

;void prt_center(strg,field_size,fill_char,printer_codes) ; char *strg,fill_char,*printer_codes; ; int field_size; EXTRN _memory_model:byte EXTRN _error_code:byte EXTRN _time_out:byte _TEXT SEGMENT BYTE PUBLIC 'CODE' ASSUME CS:_TEXT PUBLIC _prt_center _prt_center proc near push bp ; mov bp,sp ; push di ; push si ; push ds ; cmp _memory_model,0 ;near or far? jle begin ;jump if near inc bp ;else add 2 to BP inc bp ; begin: jmp short A1 keep_count dw ? keep_target dw ? strg_len db ? right_border dw ? field_size db ? fill_char db ? codes_seg dw ? codes_ofs dw ? A1: mov ah,1 ;BIOS func to init prtr sub dx,dx ;choose LPT1 int 17h ;initialize the prtr port sub ax,ax ;clear AX mov es,ax ;point ES to 0000:0000 mov dx,es:[408h] ;get LPT1 base address mov _error_code,1 ;1 = printer error mov al,_time_out ;get _time_out seconds cmp _memory_model,2 ;data near or far? jb B1 ;jump if near lds si,dword ptr[bp+4] ;DS:SI pts to Strg mov bh,[bp+8] ;field size mov bl,[bp+10] ;fill char les di,dword ptr[bp+12] ;ES:DI pts to PrinterCodes jmp short B2 ; B1: mov si,[bp+4] ;NEAR case mov bh,[bp+6] ; mov bl,[bp+8] ; mov di,[bp+10] ; push ds ; pop es ; B2: mov cs:field_size,bh ;store parameters for later mov cs:fill_char,bl ; mov cs:codes_seg,es ; mov cs:codes_ofs,di ; or al,al ;don't allow 0 seconds in time out jnz C1 ; mov al,3 ;default to 3 seconds C1: mov cl,18 ;18 ticks per second mul cl ; mov cs:keep_count,ax ;save count sub cx,cx ;clear CX mov cs:strg_len,0 ;in case null string cmp byte ptr[si],0 ;test for null input string je F1 ; push si ;go count number code chars in Strg sub cx,cx ;also count string length sub al,al ;AL counts control codes D1: mov ah,[si] ;get char from Strg or ah,ah ;terminating null yet? jz E2 ;quit loop if so cmp ah,128 ;test lower end of range jb E1 ;jump if below cmp ah,159 ;test upper limit ja E1 ;jump if above inc al ;else inc code counter E1: inc si ;forward string pointer inc cx ;inc string length counter jmp short D1 ;go check next char E2: pop si ; mov cs:strg_len,cl ;save string length sub ah,ah ;clear AH sub cx,ax ;num printed chrs in Strg F1: sub ax,ax ;clear AX mov al,cs:field_size ;line length (255 max) or al,al ;test for zero jz M1 ;quit if zero cmp cx,ax ;compare Strg, field lens jbe G1 ;jump if Strg <= mov cx,ax ;print only part of Strg mov cs:strg_len,cl ; sub ax,ax ;use 0 in calculation jmp short H1 ;jump below G1: sub ax,cx ;minus string length H1: mov cx,ax ;copy in CX shr ax,1 ;div by 2 sub cx,ax ;remainder mov cs:right_border,cx ;save right border length mov cx,ax ;left border jcxz J1 ;jump if no left border I1: mov al,cs:fill_char ;fetch fill character call Writeit ;print a char or ah,ah ;check for printer error jz M1 ;quit if error loop I1 ;go do next on left J1: mov cl,cs:strg_len ; mov ch,cs:fill_char ;copy fill char in CH or cl,cl ;test for null string jz R1 ;jump ahead if null K1: mov al,[si] ;get a character cmp al,128 ;test if control code jb P1 ;jump if below range cmp al,159 ;test if above ja P1 ;jump if above push cx ;save Strg len ctr push si ;save Strg pos ptr push ax ;point ES:DI to PrinterCodes mov ax,cs:codes_seg mov es,ax mov di,cs:codes_ofs pop ax sub al,128 ;count codes from 0 mov cl,6 ;times six bytes mul cl ;offset in PrinterCodes add di,ax ;SI pts to code sequence sub cx,cx ;clear CX mov cl,es:[di] ;get string descriptor jcxz O1 ;quit loop if null L1: inc di ;forward ptr mov al,[di] ;get code character call Writeit ; or ah,ah ;printer error? jnz N1 ;continue if not pop si ;restore Strg pos ptr pop cx ;restore Strg len ctr M1: jmp short U1 ;go quit routine N1: loop L1 ;go do next O1: pop si ;restore Strg pos ptr pop cx ;restore Strg len ctr jmp short Q1 ;go get next char in Strg P1: call Writeit ; or ah,ah ;proc returned error? jz U1 ;quit if so Q1: inc si ;forward Strg ptr dec cl ;dec Strg len ctr jnz K1 ;loop till finished R1: mov al,ch ;fill char to AL mov cx,cs:right_border ;right border length jcxz T1 ;quit if no right border mov ch,al ;copy back to CH S1: mov al,ch ;fill char to AL call Writeit ; or ah,ah ;check for printer error jz U1 ;quit if error dec cl ;dec border len counter jnz S1 ;loop till finished T1: pop ds ; dec _error_code ;0 = no error jmp short V1 ; U1: pop ds ; V1: pop si ; pop di ; pop bp ; cmp _memory_model,0 ;quit jle quit ; db 0CBh ;RET far quit: ret ;RET near Writeit PROC out dx,al ;send to output data register inc dx ;forward to status register push cx ;save string counter call GetBiosCount ;get timer reading mov bx,cx ;make copy add cx,cs:keep_count ;add delay count cmp bx,cx ;if timer doesn't turn over... jb W1 ;go ahead mov cx,cs:keep_count ;otherwise, extend delay W1: mov cs:keep_target,cx ;save target count on stack Wait: in al,dx ;get status value test al,8 ;test for printer error jz Error ; test al,80h ;test for Printer Ready jnz Ready ;jump if ready Error: call GetBiosCount ; cmp cx,cs:keep_target ;compare to target jb Wait ; mov bl,1 ;1 = error pop cx ;restore string counter mov ah,0 ;return code for failure jmp short X1 ;return Ready: pop cx ;restore string counter inc dx ; output control register mov al,13 ;bits for strobe signal out dx,al ;send the signal dec al ;change to strobe OFF out dx,al ;send the signal dec dx ;point back to dec dx ; base address mov ah,1 ;return code for success X1: ret ; Writeit endp GetBIOSCount PROC push dx ;return value in CX:DX push ax ; sub ah,ah ;function number int 1ah ;get timer count mov cx,dx ;low word in CX pop ax ; pop dx ret GetBIOSCount endp _prt_center endp _TEXT ENDS END