Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!texbell!merch!cpe!hal6000!trsvax!slimer
From: slimer@trsvax.UUCP
Newsgroups: comp.sys.ibm.pc
Subject: Re: How can I poll a drive?
Message-ID: <216100138@trsvax>
Date: 8 Sep 89 13:59:00 GMT
References: <342@castle.ed.ac.uk>
Lines: 45
Nf-ID: #R:castle.ed.ac.uk:342:trsvax:216100138:000:1286
Nf-From: trsvax.UUCP!slimer    Sep  8 08:59:00 1989



  What you would want to do is this...

  union REGS inregs, outregs;
  char drive_value;

  main()
  {

  /* Set up for IOCTL Function call */

  inregs.h.ah = 0x44;
  inregs.h.al = 0x0e;

  /* Get Logical Drive Map */

  drive_value = "C";     /* Set check for drive C */

  inregs.h.bl = (drive_value - "A" + 1)                            

  intdos(&inregs,&outregs);

  printf("Drive %c does %sexist.",drive_value,          
	((outregs.x.cflag & 1) ? "not " : ""));

  }



  What this routine will do is test for the logical drive of C. If it
  exists, then the outregs.x.cflag test will fail and the message will be
  DOES EXIST. I use the function call 0x44 for interrupt 21 because it only
  does a system configuration block devices, it never actually accesses any
  disk. By placing your own values in the drive_value character, it will
  test for different drives.

  Have Fun!


****************************************************************************
*  Thank You,                           texbell!letni!rwsys!trsvax!slimer  *
*         Bill                            "I do windows." - ComputerWorld  *
*  George W. Pogue, 1300 Two Tandy, Fort Worth, TX. 76102  (817) 390-2871  *
****************************************************************************