TITLE NWS - ASSEMBLER PROGRAM TO STRIP HI-ORDER BITS FROM WORDSTAR FILES SUBTTL DESCRIPTION OF THE STACK SEGMENT PAGE STACK SEGMENT PARA STACK 'STACK' DB 64 DUP('STACK ') STACK ENDS SUBTTL DESCRIPTION OF THE DATA SEGMENT PAGE WORKAREA SEGMENT PARA PUBLIC 'DATA' LOGO DB ' ***********************************************************************',10,13 db ' * *',10,13 db ' * UN - Wordstar *',10,13 db ' * A program to remove the high-order bits from Wordstar data *',10,13 db ' * files. You are prompted for the input and output file names. *',10,13 db ' * *',10,13 db ' * Written as an assembler language example by Gene Plantz *',10,13 db ' ***********************************************************************',10,10,10,10,13,'$' donem db '--------> DONE <-------------',10,13,'$' eofflag db 0 crlf db 10,13,'$' ;issue carriage return-linefeed after input fcb1 db 40 dup(0) ;input file only needs to be 36 (but safe) fcb2 db 40 dup(0) ;file control block for output err0 db 7,7,'---> ERROR Opening INPUT file <--------',10,13,'$' err1 db 7,7,'---> ERROR.. not enough disk space for output <---',10,13,'$' err2 db 7,7,'---> ERROR.... bad file name given. <----',10,13,'$' parms db 14 ;max size of reply repson db ? ;size of what they typed name1 db 20 dup(' ') ;this is where the users reply goes parms2 db 14 ;max size of input resp2 db ? ;size of what they really typed in name2 db 20 dup(' ') ;this is where the reply goes ask1 db 10,10,13,'Please Enter the name of the input file $' ask2 db 'Please Enter the name of the output file $' buffer db 128 dup(' ') ;record buffer workarea ends ; subttl desciption of dos interfaces cseg segment para public 'CODE' start proc far assume cs:cseg,ds:workarea,ss:stack,es:workarea org 100h push ds ;set up starting linkage as per dxample sub ax,ax ;zero this and place on stack push ax ;so that when we do a RET we go to mov ax,workarea ;location 0; point to our workarea mov ds,ax ;move the workarea address into DS mov es,ax ;also into ES for the function 29H call cls ;call subroutine to clear the screen mov dh,3 ;set cursor to row 8 mov dl,0 ;set cursor to column 0 mov bh,0 ;use screen number 0 mov ah,2 ;function 2 to locate cursor int 10h ; go do it mov dx,offset logo ;display the logo where we put cursor mov ah,9 ;function 9 is print string int 21h ;call dos to do it ; mov dx,offset ask1 ;point to message to display mov ah,9 ;tell DOS what function (print string) int 21h ;call DOS ; mov dx,offset parms ;point to console input buffer mov ah,10 ;read console buffer int 21h ;do it ; mov si,offset name1 ;put address of name1 into SI mov di,offset fcb1 ;put address of file control block DI mov ah,29h ;tell DOS to parse filename int 21h ;do it ; mov dx,offset crlf ;do a carriage return-line feed mov ah,9 ;after the reply int 21h ;to DOS ; mov al,[di+1] ;if DI+1 = blank, no file name cmp al,20h ;if blank, error jnz isok jmp error2 ; isok: mov dx,offset ask2 ;ask user for name of new file mov ah,9 ;display question int 21h ;DOS ; mov dx,offset parms2 ;put address of input buffer into DX mov ah,10 ;get input from user int 21h ;DOS ; mov dx,offset crlf ;another cr,lf mov ah,9 int 21h ; mov si,offset name2 ;SI = address of field NAME2 mov di,offset fcb2 ;DI = address of second file control mov ah,29h ;ask DOS to parse filename int 21h ;DOS ; mov al,[di+1] ;if DI+1 = blank, error cmp al,20h ;is it blank?? jz error2 ;tell him and leave yyyyy ; mov dx,offset fcb1 ;point to first fcb mov ah,15 ;open the input file int 21h ;call dos to do it ; cmp al,0 ;see if ok jnz error0 ;tell him and leave ; mov dx,offset fcb2 ;address of fcb2 mov ah,16h ;create out put file int 21h ;this does open, too ; mov dx,offset buffer ;point to out record buffer mov ah,1ah ;tell DOS to put disk data there int 21h ;DOS ; readl: cmp eofflag,1 ;see if end-of-file was reached jz closeall ;yes, wrap it up and leave mov dx,offset fcb1 ;read from file 1 mov ah,14h ;sequential read from disk int 21h ;DOS ; cmp al,0 ;see if normal return jz readok ;if zero, ok mov eofflag,1 ;no, set end-of-file flag jmp readl ;back to read ; readok: mov cx,128 ;size of logical record mov si,offset buffer ;SI = address of our buffer andloop: ;these 3 lines were used because ; AND [SI],7FH wouldn't assemble ; mov al,[si] ;and out the hi-bit and al,7fh mov [si],al ;put it back ; inc si ;bump pointer to next char in buffer loop andloop ;do it 128 times (in CX) ; mov dx,offset fcb2 ;point to output fcb mov ah,15h ;sequential write int 21h cmp al,1 ;this means disk full jz error1 ; jmp readl ;do it again ; closeall: mov dx,offset fcb2 ;close output file mov ah,10h int 21h ; mov dx,offset donem ;iisue DONE message mov ah,9 int 21h jmp exit ; error2: mov dx,offset err2 ;err mess 2 jmp errorm error1: mov dx,offset err1 ;point to error mess number 1 jmp errorm error0: mov dx,offset err0 errorm: mov ah,9 ;print it int 21h jmp closeall exit: ret start endp ; ; subttl clear screen routine cls proc near mov cx,0 mov dx,2479h mov bh,7 mov ax,600h int 10h ret cls endp ; ; cseg ends end start 65399 '** DONE - PRESS ENTER TO RETURN TO MENU **  10h ret cls endp ; ; cseg ends