[comp.sys.att] Bigger disks for AT&T 3B2/310 -- su

rjd@tiger.UUCP (05/06/87)

>I am interested in purchasing a larger hard disk for my
>AT&T 3B2/310. I'd appreciate info about vendors, experience,
>etc. Please respond by e-mail to
>
>	Ed Scheinerman	msc_wers@jhunix

   Can't email to jhunix from this site, and since no complete path is given,
I will post:

   If you are looking for a larger integral disk (boot disk) for your 310,
the largest that AT&T supports is the 86 MB (72 MB formatted) found in certain
configurations (otherwise you started with a 36 MB [32 formatted]).  If you
are needing a larger boot disk (you don't specify, and I do not see any reason
that you would care, unless it is due to external space limitations), you may
be out of luck.  If you just need more disk space and do not care if it fits
into the 310 case (no other disks will), look into buying expansion modules.
Three routes:
   1) adding a second disk to your 310 through the disk control and data ports
      on the back of the 310.  An XM is sold for this purpose.
   2) adding number 1) above and/or adding an XDC (eXternal Disk Controller)
      and associated expansion module (XM) to the 310.  The XDC will support
      two disk drives, so that you could have three added by putting one on
      according to 1) and two more with the XDC.  The XDC occupies one I/O
      slot.
1 and 2 both use the same disk drives that are put into the case, the options
of which ar the 32 or 72 MB size.
   3) Add SCSI to your system.  (Small Computer Systems Interface)  Numbers
      one and two may be cheaper (I do not know), but the SCSI interface will
      allow more expansion: up to 28 135 MB disks off of one I/O slot.  (Yes,
      28 X 135 MB = 3.78 GB!!)  I am unsure at the moment of the exact size of
      these SCSI drives that are being marketed at the moment, but they are in
      the area of 135 MB.  The SCSI interface will allow the connection of other
      devices other than disk drives.  You can, for instance, configure it
      with a maximum of 24 disks and one 9-track tape drive (of course, you
      can put just one disk on it and expand it later...).


--------------------------------------------------------------------------------
Randy Davis                     		UUCP: ...(ihnp4!)3b2fst!randy
3B2 System Test Engineering
AT&T Oklahoma City Works
All opinions and/or advice stated above are MY OWN, not those of AT&T.
--------------------------------------------------------------------------------

kai@ihlpa.ATT.COM (Irwin) (05/09/87)

> 
> >I am interested in purchasing a larger hard disk for my
> >AT&T 3B2/310. I'd appreciate info about vendors, experience,
> >etc. Please respond by e-mail to
> >
> >	Ed Scheinerman	msc_wers@jhunix
> 
>    Can't email to jhunix from this site, and since no complete path is given,
> I will post:
> 
>    If you are looking for a larger integral disk (boot disk) for your 310,
> the largest that AT&T supports is the 86 MB (72 MB formatted) found in certain
> configurations (otherwise you started with a 36 MB [32 formatted]).  If you
> are needing a larger boot disk (you don't specify, and I do not see any reason
> that you would care, unless it is due to external space limitations), you may
> be out of luck.  If you just need more disk space and do not care if it fits
> into the 310 case (no other disks will), look into buying expansion modules.
> Three routes:
>    1) adding a second disk to your 310 through the disk control and data ports
>       on the back of the 310.  An XM is sold for this purpose.
>    2) adding number 1) above and/or adding an XDC (eXternal Disk Controller)
>       and associated expansion module (XM) to the 310.  The XDC will support
>       two disk drives, so that you could have three added by putting one on
>       according to 1) and two more with the XDC.  The XDC occupies one I/O
>       slot.
> 1 and 2 both use the same disk drives that are put into the case, the options
> of which ar the 32 or 72 MB size.
>    3) Add SCSI to your system.  (Small Computer Systems Interface)  Numbers
>       one and two may be cheaper (I do not know), but the SCSI interface will
>       allow more expansion: up to 28 135 MB disks off of one I/O slot.  (Yes,
>       28 X 135 MB = 3.78 GB!!)  I am unsure at the moment of the exact size of
>       these SCSI drives that are being marketed at the moment, but they are in
>       the area of 135 MB.  The SCSI interface will allow the connection of other
>       devices other than disk drives.  You can, for instance, configure it
>       with a maximum of 24 disks and one 9-track tape drive (of course, you
>       can put just one disk on it and expand it later...).

actually all 3B2/310s, 3B2/400s, and AM6 and later 3B2/300s (some later AM5s 
engineering traces added to the HDU controller chip, (AM is the boards Art
Master number on rear of board behind memory slots)) are capable of addressing
20 data heads on any st506 interface drive (with a properly written vtoc entry)
this covers all drives that I know of with that interface!!! On machines with
2.0.4 or earlier UNIX installed the standard "vtoc" files are in /etc/vtoc
to give you an idea what they look like, the file name contains the default
drive ID. These vtocs are also on the first "essential utilities" disk and can
be looked at by mounting /dev/ifdsk05 (not 06). If you put a non-standard drive
on a 3B2 (ie: no vtoc file) back up your drive and make a copy of the first
core (essential utilities) floppy, mount the copy (ifdsk05) and modify a vtoc
entry your not going to use (there isn't a lot of spare room on the floppy, so
don't just create another file (you will run out of tmp space when you try to
install unix!!!) format the drive and reinstall unix.

If you bought your machine through a VAR ask them to help (I'm sure they know!)
and the most widly used BIG drive is the MAXTOR (4000 series I think?) available
in 180MB sizes (about 140 formatted) this is about the largest drive I know of
with an st506 interface, these will fit internal in a 3B2/3XX and are fast.
They are however a little noisier than the standard drives (not extreem). Many 
a 3B2/400 have been sold in 300Mb internal storage utilizing these drives!


NOTE: This has been done by just about every AT&T VAR (Value Added Reseller)
in the country and is not some closley guarded secret, so no flames! And as a
matter of fact AT&T even has a tool available to do just that (I don't however
know if that is generally available) its called "dev tools" and a version IS
sold for the UNIXpc. 


and as a response to the SCSI idea 135MB in a SCSI drive is pretty piddly these
days SEVERAL manufactures are in the 300MB range and at least one is in the 
700MB range (5 1/4" drives kids) and if you use a SCSI to SMD bridge you can
get yer' gigs a drive at a time! ( thats one drive one gig, 24 drives 24 gig )
and if you're an EXTREEEEM pack rat, with SCSI there are arrays of WORM optical 
disks to get you into the terabytes (this of course is for people that save 
bent staples and used masking tape, or have a hankerin' to spend there life time
key in the library of congress (`grep -i "icabod crane" Lib_Of_Con' could take 
years to complete!))


K. A. Irwin    .....np4!ihlpa!kai


disclaimer:
the above configurations are not supported by my employer, but than again if
they were you probably wouldn't have asked!