Example Using C or Assembly to Scroll Text for FORTRAN

• Microsoft FORTRAN for MS-DOS and OS/2 versions 4.1, 5.0 and 5.1

SUMMARY

With an OUTTEXT call, it is not possible to embed CR/LF characters to enforce scrolling of text on the screen. To scroll the text, an assembler or C routine may be used as follows:

1. Use SETTEXTPOSITION to position the cursor on the screen.

2. Use OUTTEXT to display the output at that position.

3. Call an Assembly or C routine to scroll the screen by one line.

4. Return to step 1 above, positioning the cursor at the same location on the screen.

MORE INFORMATION

The following code sample illustrates the use of the assembly routine:

Sample Code (.for)

       interface to subroutine scroll_line()
       end
       include 'fgraph.fi'
       include 'fgraph.fd'
       record/rccoord/curpos

       call settextposition (10,20,curpos)
       call outtext('Hello1')

       call scroll_line()

       call settextposition (10,20,curpos)
       call outtext ('Hello2')
       end

Sample Code (.asm)

.model large,fortran

.code

scroll_line proc far

     push bp
     mov bp, sp
     mov ah,6          ;function 6H
     mov al,1          ;number of lines to scroll
     mov ch,0          ;row of top left corner
     mov cl,0          ;col of top left corner
     mov dh,24         ;row of bottom right corner
     mov dl,79         ;col of bottom right corner
     mov bh,7          ;attribute of line
     int 10h           ;interrupt 10h
     pop bp
     ret

     end

       interface to subroutine scroll_line [FAR,C] ()
       end

Sample Code (C)

#include <stdio.h>
#include <dos.h>

void scroll_line()

/*
 *  The registers have the same significance as those in
 *  the assembly-language routine above.
 */

  reg.h.ah = 6;     // function 6H
  reg.h.al = 1;     // number of lines to scroll
  reg.h.bh = 0x7;   // attribute of line
  reg.h.ch = 0;     // row of top left corner
  reg.h.cl = 0;     // column of top left corner
  reg.h.dh = 24;    // row of bottom right corner
  reg.h.dl = 79;    // row of top right corner

  int86(0x10, &reg, &reg);
  return;

The following is the MAKE file when the assembly module subroutine is used:

Makefile (Assembly)

all=1.obj 2.obj

update: 1.for

    fl /Zi /c 1.for

    masm /Zi 2.asm;

The following is the MAKE file when the C module subroutine is used:

Makefile (C)

all=1.obj 2.obj

update: 1.for

    fl /Zi /c 1.for

    cl /AL /Zi /c 2.c

    link $(all)/co,,,/nod /noe graphics llibfer llibcer;