Date: Thu, 8 Jun 1995 09:20:25 +0300
From: eliz AT is DOT elta DOT co DOT il (Eli Zaretskii)
To: djgpp AT sun DOT soe DOT clarkson DOT edu, clef AT aber DOT ac DOT uk
Subject: Re: Floppy Error Msg supression

> Does anybody know how to supress the 'Abort,Retry, or Cancel' msg when you 
> don't have a floppy disc loaded and you've tried to save/load. We've got this 
> box with a 386 in it and no monitor (or keyboard). We get interaction from a 
> series of knobs and buttons.

You can try to read the first disk sector with a BIOS call, like this:

          unsigned char buf[512];
          int bios_status, count = 0;
 
          /* Int 13h/AH=02h returns 6 for disk changed, even if the
             disk isn't readable (e.g., unformatted).  Retry the
             operation after disk change, each time resetting the 
             drive, until something other than 6 is returned or we
             run out of our patience.  */
          while (++count < 10 && (bios_status =
                 biosdisk(2, drive_number - 1, 0, 0, 1, 1, buf)) == 6)
            biosdisk(0, drive_number - 1, 0, 0, 0, 0, NULL);
 
          /* If the loop ends with nonzero status, fail.  */
          if (bios_status != 0)
            do-whatever-it-takes-for-empty-drive;