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Date: Fri, 26 Jul 1996 15:15:02 +0000 ()
From: David Brockus <dbrockus@cyberhall.com>
To: FreeBSD questions <questions@freebsd.org>
Subject: Tape Drive error messages
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I installed an HP Colorado T4000s tape drive (SCSI-2 TR-4) in a FreeBSD 
2.0.5R machine with an Adaptec 2940 controller.  

I installed the drive in case, configured the kernel, and rebooted.  It 
recognizes the tape drive.

I ran 'mt' to check the drive status and got this.

cyber1# mt status
Present Mode:   Density = 0x45         Blocksize = 512 bytes
---------available modes---------
Mode 0:         Density = 0x00         Blocksize variable
Mode 1:         Density = 0x00         Blocksize variable
Mode 2:         Density = 0x00         Blocksize variable
Mode 3:         Density = 0x00         Blocksize variable

I got the following system error message

st0(ahc0:4:0): ILLEGAL REQUEST asc: 24,0 Invalid field in CDB
st0: Cannot set selected mode

What is CDB?

I have obviously missed something, but I am not sure what. 

I am new to installing/using tape drives on unix systems, so I apologize 
in advance if this is a stupid question.

Is there a device setup file where I specify the density and blocksize 
for each mode?

I have found some technical info about TR-4 media
	
	QIC-3095
	Number of Tracks: 73
	Bit density: 67,733 (docs didn't say if per inch or not)  
	Encoding method: RLL1,7
	Length: 270 ft.

My problem is what do I do with this information?  In the man page for 
'mt' that specific bit density is not supported, do I just pick the 
closest match?  

Any suggestions would be greatly appreciated.

David Brockus