---
title: "Displaying QL Screens In MS-DOS"
type: "article"
slug: "displaying-ql-screens-in-ms-dos"
url: "http://localhost/article/displaying-ql-screens-in-ms-dos/"
markdown_url: "http://localhost/article/displaying-ql-screens-in-ms-dos.md"
published_at: "2025-12-18T14:53:13+00:00"
modified_at: "2026-06-21T23:26:55+00:00"
featured_image:
  url: "http://localhost/wp-content/uploads/2022/04/20230809-041332.jpg"
excerpt: "[It's not normally the policy of the QHJ to publish programs that are written for other platforms than the QL. But in this case, I can make an exception. The following program by Jeff Kuhlmann is designed to display a QL screen file on an MS-DOS computer. I've tried it with my MS-DOS laptop (CGA…"
category:
  - name: "QL Hacker's Journal"
    slug: "ql-hackers-journal"
    taxonomy: "category"
    url: "http://localhost/category/periodicals/ql-hackers-journal/"
post_tag:
  - name: "C (programming language)"
    slug: "c-programming-language"
    taxonomy: "post_tag"
    url: "http://localhost/tag/c-programming-language/"
  - name: "Full Text"
    slug: "fulltext"
    taxonomy: "post_tag"
    url: "http://localhost/tag/fulltext/"
  - name: "QL"
    slug: "ql"
    taxonomy: "post_tag"
    url: "http://localhost/tag/ql/"
model:
  - name: "Sinclair QL"
    slug: "sinclair-ql"
    taxonomy: "model"
    url: "http://localhost/model/sinclair-ql/"
indiv:
  - name: "Jeffrey Kuhlmann"
    slug: "jeffrey-kuhlmann"
    taxonomy: "indiv"
    url: "http://localhost/indiv/jeffrey-kuhlmann/"
publication_r:
  id: 33686
  title: "QL Hacker’s Journal"
  type: "periodical"
  url: "http://localhost/periodical/ql-hackers-journal/"
authors_r:
  - name: "Jeffrey Kuhlmann"
    slug: "jeffrey-kuhlmann"
    taxonomy: "indiv"
    url: "http://localhost/indiv/jeffrey-kuhlmann/"
issue: "19"
issues_articles:
  - id: 61555
    title: "QL Hacker’s Journal 19"
    type: "issue"
    url: "http://localhost/issue/ql-hackers-journal-19/"
pubdate: "November 1994"
archive_link: true
---

[It’s not normally the policy of the QHJ to publish programs that are written for other platforms than the QL. But in this case, I can make an exception. The following program by [Jeff Kuhlmann](http://localhost/indiv/jeffrey-kuhlmann/) is designed to display a QL screen file on an MS-DOS computer. I’ve tried it with my MS-DOS laptop (CGA display) and with a 486 (VGA display) and it works fine on both computers.

As more and more QLers are buying PC’s, programs like this are becoming more useful. – ED]

```
/* SHOWGR.C - A 'C' PROGRAM TO DISPLAY '_GR' FILES
 FROM THE MDOS PROMPT */
/* JEFFREY A. KUHLMANN 27FEB94 */

#include "graphics.h"
#include "stdio.h"
#include "string.h"
#include "stdlib.h"
#include "io.h"
#include "conio.h"

char infn[81];  /* input file name */
char str1[81];
char buf[128*200+128];
FILE inf;
int arry[20];   /* utility array */
char rows[81];  /* row string */
char cols[81];  /* columns string */
int ctr,end,delim,col,row;
int rctr,cctr,cptr;
int chardat[8],chrptr;
char hexdat[81];
int hex[4];
int blank[4],where,pval,ccc;
int mptr,fd,gm;

main(argc,argv)
int argc;
char **argv;
{
gm=5;                   /* Graphic Mode */
if (argc<2) /* If no file name given on command line, */
{                       /* ask for one */
setvmode(2);
puts("QL SCREEN VIEWER FOR MDOS");
puts("Press any key when done");
puts("viewing picture...");
puts("QL SCREEN file name? (w/o .SCR)");
gets(infn);
}
else strcpy(infn,argv[1]);
strcat(infn,".SCR");    /* add required extension */
setvmode(gm);           /* change video mode */
fd=open(infn,O_BINARY); /* open file for reading */
mptr=0;
if (fd==-1) {setvmode(2); printf("Can't open %s",infn);
    exit(0);}
read(fd,buf,128*200);
   /* ^ read first 200 lines into a buffer */
 for(rctr=0;rctr<200;rctr++)
   /* ^ 200 pixels in 'y' direction */
  for(cctr=0;cctr<128;cctr++)
   /* ^ each QL line is 128 bytes */
  { pval=buf[(rctr)*128+cctr];
    if(rctr&1)               
     /* ^ need to take into account odd scan line */
    poke(0xba00,(rctr-1)*40+cctr/2+8,pval);
    else
    poke(0xb800,rctr*40+cctr/2+8,pval);
 }
while(!kbhit());    /* wait for keypress */
setvmode(2);        /* restore 80 col. mode */
exit(0);
}
```