Subject: Re: next question: scsi Tapes
To: None <>
From: mark thompson <>
List: macbsd-general
Date: 12/28/1994 11:31:42
At 11:39 AM 12/27/94 -0500, Allen Briggs wrote:
>> 1) How come the character (raw) scsi tape device read and write routines are
>>  disabled (in the cdev switch)? The block read and write routines work.
>You generally don't mess with tapes in anything but blocks.  At least,
>that's my best estimation of why there aren't any character devices for
>the tape.  The drivers were written by Julian Elischer a while back and
>we just implemented the low-level parts.
Well, my memory is that the raw devices worked on my PC (NetBSD 1.0). I
note that the mac port has its own copies of the SCSI drivers, which seems
odd, since nothing should be different except the lower levels...

Also, there is SOURCE for the character read and write routines, you just
can't get to them because of the contents of the cdev switch.

The DAT drives write variable blocks, and so using the raw device is almost
a necessity.

>> 2) I am running MRG, and playing with tapes. Doing a dump (or maybe trying
>> to read the dump tape to make sure it was ok) seems to have wiped out the 
>> root partition, had to rebuild it. Was using /dev/st0 (see question 1).
>Ack!  Did you have any panics or errors or anything in the process?
Well, not until i tried to reboot and it couldn't find init.

>> Am I getting out into uncharted territory here?
>Yes.  I used a tape drive a while ago, but I haven't tried it recently.
>It was a QIC drive and I no longer have it.  :-(
Well, I will do some more hacking on it then, and report what I find. 
Are the 'best' sources available (i.e. is there anything more recent than
the stuff in the NetBSD-1.0 archives)?


p.s. Oh yeah. Are the floppies supposed to work?