Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!magnus.acs.ohio-state.edu!tut.cis.ohio-state.edu!uoft02.utoledo.edu!desire.wright.edu!jmatthews
From: jmatthews@desire.wright.edu
Newsgroups: comp.sys.mac.programmer
Subject: Re: trapping for floppy diskDOWN
Message-ID: <1991Mar26.231454.3002@desire.wright.edu>
Date: 27 Mar 91 04:14:54 GMT
References: <1991Mar19.164204.8847@hubcap.clemson.edu> <6761@rex.cs.tulane.edu> <23818@well.sf.ca.us>
Organization: University Computing Services, Wright State University
Lines: 47

>>>I am working on an init that traps on MountVol.  What I want to do
>>>is to distinguish between floppies and hard disks.  Can anybody help 
>>>me out?  Sample code would be appreciated.  Thanks in advance.

Here's some code to call the disk driver. The first drive in the
queue is

  currentDrive := GetDrvQHdr^.qHead^.drvQElem;

subsequent elements are

  currentDrive := currentDrive.qLink^.drvQElem;

You can call the driver's Control routine thus:

  function FloppySize (currentDrive: DrvQEl): Integer;
    var
      info: Integer;
      pBlock: ParamBlockRec;
  begin
    FloppySize := 0;
    with pBlock, currentDrive do
      begin
        ioVRefNum := dQDrive;
        ioRefNum := dQRefNum;
        csCode := 23; {IM V p 470}
        if PBControl(@pBlock, false) = noErr then
          begin
            info := BitAnd(csParam[1], $F);
            if info = 2 then
              FloppySize := 400
            else if info = 3 then
              FloppySize := 800
          end
      end
  end;

You might look at bits 8 through 11 for information about whether
a drive is SCSI/IWM (bit 9), or fixed/removable (bit 10).

The real question: "is the drive queue initialized at INIT
time?"

o----------------------------------------------------------------------------o
| John B. Matthews, jmatthews@desire.wright.edu, am103@cleveland.freenet.edu |
| "Say...what's a mountain goat doing way up here in a cloud bank?" - Larson |
o----------------------------------------------------------------------------o