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DAT Drive C1533A microswitches

Roberto Cantu'
Occasional Contributor

DAT Drive C1533A microswitches

Simply, I can't find any documentation about them.
Is there anybody who can help me?
Thanks. Roberto.


P.S. This thread has been moved from Storage>General to Tape Libraries and Drives. -HP Forum Moderator

Bob Light
Frequent Advisor

Re: DAT Drive C1533A microswitches


The following information is for the 8 unit micro switch on the bottom of the
drive. The host control
part is usually only for UNIX or MPE controllers.
The default settings are sw1,sw4-sw8 set to 1 and
sw2 and sw3 set to 0

C1533A/C1536A/C1537A/C1539A/C156XB Switch Setting and Definitions

Exchange Mech P/N C1533-69203

Exchange Mech P/N C1536-69203

Exchange Mech P/N C1537-69201

Exchange Mech P/N C1539-69201

Exchange Mech P/N C1560-69301

Switch(s) Position

Sw1 set to 0, Sw2 set to 0 Compression disabled, No Host Control

Sw1 set to 0, Sw2 set to 1 Compression disabled, Host Control

Sw1 set to 1, Sw2 set to 0 Compression enabled, No Host Control

Sw1 set to 1, Sw2 set to 1 Compression enabled, Host Control

Sw3 thru sw8 set to 1 (ON) Media Recognition disabled.

Sw3 set 0 (OFF),Sw4-Sw8 set to 1 (ON)Media Recognition enabled.

Bob Light

Bill Day
Occasional Visitor

Re: DAT Drive C1533A microswitches


At least on the old /tape site I could find info quick.
Using SEARCH at the new site fails miserably for 2 common items that I used to
regularly find in seconds.
We just ordered our second DAT24eU for some unix boxes. This is specifically
sold for unix, and the printed Install manual that came with it doesn't even
hint at where to find the specific details one needs. So at least try to get
your website search to find the info easily, as it once did. (TWO EXAMPLES

ITEM 1. I used to be able to find at www.hp.com/tape a web page for each of
several flavors of unix. Each page told how to use the dat24, had graphic
showing the 8-pole dip-sw settings and step-by-step instructions for editting
unix scsi files, etc. Over an hour of searching has led me in countless loops.
The stuff I could find was worthless. For example, a table where you click on
the green dots at intersection of your drive type and your flavor of unix. But
for sgi (irix), solaris and each of several others there was only a useless
blurb about looking in some (out-of-date) unix printed manual. None gave the
dip-switch settings or scsi configuration file editting instructions I remember
finding on your web site some time last year (1999). Finally in an old
bookmark, bingo! I found it:


I then tried a search of all tape info at /storage, and even using the actual
name of the above page, could not find it: "UNIX Configuration Guide". Please
make this useful info readily findable for the next poor person!

ITEM 2. Only 1 useless hit on C1537A internal ID.

You should at least get the search engine on your website to provide a
cross-reference from internal id C1537A to Drive Type (DAT24) as found in
manual below.
Most folks aren't going to open a box to find the exact model number. The tape
tools software apparently can't tell you whether you have a DAT24e or DAT24eU
it seems.

I only get 1 hit that even mentions my C1537 dat24 tape drive: a reply from
HP's Bob Light (United States) RE: DAT Drive C1533A microswitches

This single hit gave C1533A/C1536A/C1537A/C1539A/C156XB Switch Setting and
Definitions, but nothing on unix scsi conf file strings. HP dropped unix tape

The dat24e/eU product specs do NOT list a C1537A at all
I recently bought a second dat24eU, which comes with a "Generic" Installation
Guide whose title page says:

For "e" model drives, refer to Chapter 1.
For "eU" model drives, refer to Chapter 2.

NONE of these tell you if you have e or eU drive:
Nowhere I can find in the manual, which is too generic.
The id tag gives only model and serial number.
The faceplate says just "DAT24". So if the cardboard box it came in is gone,
you have to go to the website to cross-ref the model# to DAT24e or DAT24eU or

On both page 1-7 and 2-5 of then Install manual is the same table saying
HPC1537A is just a DAT24 . It does NOT say DAT24e or DAT24eU. So I guess you
can't tell by the "Internal Identifier which applications recognize rather than
their model numbers " as each table says.

So I'm not sure if I have a dat24e or dat24eU unless I disassemble, look at the
model number on drive id tag, then goto the website and search around for it.

Oldest drive I have reports SCSI info as "C1537A L708". It seems that L708 is
indeed the latest firmware version. Perhaps the next version of firmware could
return an Internal ID that includes full model name, such as:

"C1537A L708 DAT24EU". That would help us all!

-Thanks, Bill Day March 23, 2000