Imaging SCSI hard disks

From: Paul Koning <>
Date: Thu Sep 2 08:41:41 2004

>>>>> "Ethan" == Ethan Dicks <> writes:

 Ethan> On Wed, Sep 29, 2004 at 10:48:11PM -0400, Jerome H. Fine
 Ethan> wrote:
>> HELP!! Something seems to be missing. Is SIMH being used with
>> SCSI hard disk drives are are the SCSI hard disk drives first
>> being copied to a hard disk file AFTER which SIMH does: ATTACH
>> RQ0: hard_disk_file.DSK I don't know of any command that allows
>> SIMH to ATTACH a raw SCSI hard drive like E11 allows. What am I
>> missing in this discussion? PLEASE!!!

 Ethan> I have no idea how to do this with any version of Windows, but
 Ethan> UNIX/Linux/etc. have always given you access to the raw disk.
 Ethan> In my case, the relevant command would resemble something
 Ethan> like...

 Ethan> ATTACH RQ0: /dev/sda

 Ethan> (where 'sd' is the driver, and 'a' is the controller).

 Ethan> This works with any and all emulators since to UNIX, unlike
 Ethan> Windows, everything is a file. "Devices" are not special
 Ethan> entities to open()/close() calls, etc.

It's not quite that simple.

Most Unices (though not Linux) have two ways to look at disks, the
regular "block" device, and a "character"[sic] also called "raw". To
do raw disk access you have to use the raw device.

Second, the application may need to know the size of the disk. With a
file that's easy: seek to the end, and ask for the position. While
devices are "files", the seek and position technique doesn't work
there, at least not on Linux when I was digging into this some years
ago. You *can* usually find out how big a device is, but the means
are specific to each flavor of the OS.

Received on Thu Sep 02 2004 - 08:41:41 BST

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