[comp.sys.dec] CD-ROM readers on DECstation

eric@batcomputer.tn.cornell.edu (Eric Fielding) (03/08/90)

We have a CD-ROM reader attached to a IBM PC-AT via a SCSI board.  I have
been wondering if it would be possible to connect it to our DECstation 3100.  I
assume that we just need to get the right cable and check for the right SCSI
termination (since we also have a Maxtor 8760S on the DECstation).  The main
question is what kind of software is needed.  Presumably there is a low-level
driver (perhaps the "generic SCSI driver of Ultrix 3.1?", but then is there
also a higher-level program needed?  We have lots of CD-ROMs now that are
readable under DOS (I think this means the so-called "High Sierra" format),
what do these look like to an U*ix machine?

				++ERic Fielding
eric@geology.tn.cornell.edu
eric@crnlthry.bitnet

jtkohl@MIT.EDU (John T Kohl) (03/10/90)

In article <9867@batcomputer.tn.cornell.edu> eric@batcomputer.tn.cornell.edu (Eric Fielding) writes:

> We have a CD-ROM reader attached to a IBM PC-AT via a SCSI board.  I have
> been wondering if it would be possible to connect it to our DECstation 3100.

It should "work" "out of the can".  I have tested a read-write optical
CD on my DS3100 with no problems.
> Presumably there is a low-level
> driver (perhaps the "generic SCSI driver of Ultrix 3.1?", 

Yep, the Ultrix driver works fine.

> but then is there
> also a higher-level program needed?  We have lots of CD-ROMs now that are
> readable under DOS (I think this means the so-called "High Sierra" format),
> what do these look like to an U*ix machine?

My guess is that they will look like large files with a strange data
encoding format.  Since they're obviously not Unix/Ultrix file systems,
you will initially only be able to access them via something that
interprets the format in user code.

You could write a file-system-switch entry to support the High Sierra
format if you wished; then you could link this into your Unix kernel and
eventually do something like
	mount -t high-sierra /dev/rz?c /cd-rom
and look at the files in a "normal" fashion.
--
John Kohl <jtkohl@ATHENA.MIT.EDU> or <jtkohl@Kolvir.Brookline.MA.US>
Digital Equipment Corporation/Project Athena
(The above opinions are MINE.  Don't put my words in somebody else's mouth!)

gjc@paradigm.com (03/11/90)

>> but then is there
>> also a higher-level program needed?  We have lots of CD-ROMs now that are
>> readable under DOS (I think this means the so-called "High Sierra" format),
>> what do these look like to an U*ix machine?
> 

DECUS has a program and a subroutine library for reading those ISO-9660
format CD-ROMS. It was submitted for VMS systems but it probably wouldn't
be difficult to port to Ultrix. Obviously you should check comp.sources.unix
archives too.