HDTenEightyP/NetNews huggingface dataset:
Newsgroups: comp.sys.dec
Subject: Re: Help with Maxtor XT-2190
From: don@zl2tnm.gen.nz (Don Stokes)
Date: 9 Nov 92 08:17:40 GMT
Distribution: world
Organization: The Wolery

dgray@menudo.uh.edu (Dennis Gray Jr.) writes:
> Does this mean that you can use any MFM drive in a micro vax?  (how
> about a vax station?)  If this is true, is there a MAX # of
> heads/cyls?

Well, sort of.  An RQDX3 controller or MicroVAX 2000 can cope with pretty
much any MFM drive, but formatting it is a bugger.  A VS2000 can format it
from the console prompt, but you need to know how to generate some magic
numbers (and I don't).  If you have a MicroVAX or MicroPDP-11 with an RQDX3
you need the field service diagnostic kit, and said magic numbers.  I don't
think the customer diags have a good enough formatter on 'em.  Getting the
formatter out of Field Service appears not to be possible.  8-(  
(Aww, c'mon DEC!)

If you have an RQDX2 or RQDX1, you're stuck with the DEC drives (and only
the older ones at that).

--
Don Stokes, ZL2TNM (DS555)                        don@zl2tnm.gen.nz (home)
Network Manager, Computing Services Centre            don@vuw.ac.nz (work)
Victoria University of Wellington, New Zealand              +64-4-495-5052
Newsgroups: comp.sys.dec
From: plward@ll.mit.edu (paula l ward)
Subject: dxmail on ULTRIX 
Reply-To: plward@ll.mit.edu (paula l ward)
Organization: MIT Lincoln Laboratory
Date: Wed, 11 Nov 92 00:00:45 GMT


I'm using dxmail on ULTRIX and it's been working fine until I
wanted to send mail to an address of the form:

blah!blah%blah.UUCP@blah.blah.blah

It's a good address because I had someone on a SUN forward it for me.
I also tried it with the command line e-mail but it didn't like the "!".
I've tried alot of different quotes and backslashes too.

Any Ideas???

Also, does anyone know if DEC has an e-mail address for sending
questions or problems to?

Thanks in advance...



--
//////////////////////////////////////////////////////////////////////////////
                                   /
Paula L. Ward  (plward@ll.mit.edu) /   Nor deem the irrevocable Past,     
MIT Lincoln Laboratory             /     As wholly wasted, wholly vain,
244 Wood Street M-130              /   If, rising on its wrecks, at last
Lexington, MA 02173                /     To something nobler we attain.
                                   /            -LONGFELLOW,
                                   /             The Ladder of St. Augustine
                                   /
//////////////////////////////////////////////////////////////////////////////
Newsgroups: comp.sys.dec
From: dold@unislc.uucp (Clarence Dold)
Subject: Re: alpha memory requirements (vs vax) ?
Organization: Unisys Corporation SLC
Date: Mon, 9 Nov 1992 17:23:18 GMT

From article <JOHN.92Nov9101505@sekrit.WPI.EDU>, by john@sekrit.WPI.EDU (John Stoffel):

> (Clarence Dold) writes:
>> ... experience in moving code from a Motorola
>> 68040 to the Motorloa 88100 RISC set shows a substantial change in the
>> requirement for disk space for executables, as well as run-time memory.
>> I recall a comparison of ~20% for like code.

> It's been pretty good here (we're a Beta site) for compiled binary
> sizes.  You really don't notice shared libraries for most code.  Where
> it really shines is for very grahics intensive code.  We had one guy
> who went from a 1.2 Mb on disk program to 90K on the Alpha.  

I think we're talking about two different animals at once.  Going from
non-shared libraries to shared can be a major win, especially if your
X11/Motif libraries are shared (which they are not on Unisys Motorola boxes).

The other issue is the size of the executables (perhaps just .o should be
compared) for a CISC machine verses a RISC machine.  

In joining this thread, I am assuming that the VAX, non-alpha that we are
talking about is a CISC machine.  It appears that OSF verses VMS might also
be part of the conversation, but on a different thread.

-- 
---
Clarence A Dold - dold@unislc.slc.Unisys.COM
               ...pyramid!ctnews!tsmiti!dold
Newsgroups: comp.sys.dec
From: prangley@inews (Technical Services Mgr. 505-893-7164)
Subject: VAX 7610
News-Software: VAX/VMS VNEWS 1.41    
Keywords:  Does anyone have a VAX 7610 installed?  Any problems to report?
Organization: Intel Corporation
Date: Thu, 5 Nov 1992 05:58:00 GMT
From: jjr@alantec.com (Janardan Ramesh)
Newsgroups: comp.sys.dec
Subject: HELP: Decnet Phase-IV routing
Summary: Need information on how node ID is assigned on a level 2 (area) router.
Keywords: routing area phase-iv
Date: 5 Nov 92 20:01:20 GMT
Distribution: na

I am in the process of implementing DECNET phase-IV routing. When a node is
configured as a level 2 router, it is necessary to assign a different node ID
for each area the router is connected to? Should the router maintain a
different routing data base for each area? These concepts have not been
addressed clearly in the routing specification.

The configuration I was referring to, is shown below:


    --------------------------- (area 1)
		  |
	 ------------------- 
	| Router            |
	 -------------------
		  |
    --------------------------- (area 2)

Please send me e-mail at this address: jjr@alantec.com

Thanks in advance

J. Ramesh
(Alanetc)
Newsgroups: comp.sys.nsc.32k
From: jkh@esel.lotus.com (Jordan K Hubbard)
Subject: Re: bsd 4.4 port for pc532
Organization: Lotus Ireland
Date: 11 Nov 92 21:34:28

	Yes, getting a port of 386bsd-0.1 would be a great thing to do.  I have
	actually played with 386bsd (on a pc for 1 week) and I have the sources

What is this in reference to?  I seem to have missed the thread.
Gary and I were talking about this just a couple of weeks ago.

I also run 386BSD on my PC (I have for the last month and a half or so and
I'm quite happy with it).

I've had gcc producing reasonable bsd binaries for the '532 for some
time (it's not hard).  When linked with my stand-alone stdio library,
they actually run, too.  None of this is much of a trick, however.
The hard part (as I see it) is extracting the MMU setup code from the
mach port and somehow grafting it into 386BSD, as well as autoconf'ing
in the serial and scsi drivers.  Most if the 32532 specific math and
assembly code for libc can probably be stolen outright (in fact, the
386BSD math libraries compile with -DNATIONAL!).

I need to look at how much trouble the drivers are going to be, but
this is hardly my area of expertise.  Gary would be far more qualified
to comment on that.

Actually, I think this would probably amuse the hell out of Bill
Jolitz, and he could possibly even be halfway helpful with it if we
asked him nice.  Those familar with Bill's history will know why it
would amuse him to see 386BSD on a national chip.

One ofh the problems I see is hosting all this in a coordinated
fashion.  Phil appears to be trying to host from minix whereas I'm
hosting from a PC that shares the same SCSI disk (makes populating a
BSD fs with cross-compiled binaries a lot easier!).

Adding 30 character filenames to minix is very easy - I'm surprised
Phil hasn't done that particular hack yet.  In any case, I think
cross-compilation is the way to go, for now.

					Jordan
Newsgroups: comp.sys.nsc.32k
From: bdale@gag.COM (Bdale Garbee)
Subject: Re: bsd 4.4 port for pc532
Organization: Association for the Prevention of Polar Bears and Kangaroos
Date: Thu, 12 Nov 1992 15:34:52 GMT

Re porting 386bsd to the pc532.

Wouldn't it be easier to build a cross-compile environment on a 386bsd system
than to try and do this from Minix?  That's what I was hacking on last time I
had time.  I had gcc2.2.2 running as a cross-compiler, had gas running, and
was looking at ld issues when I got involved in a hardware project that has
sucked up most of my time.  

Actually, I'm using BSDI's BSD/386, and not the Jolitz bits, but for this 
purpose, they're virtually identical.

With the 386/486 and 532 chips having the same byte-ordering, it would seem to
me that the issues of processor are very managable here, and you don't have to
deal with OS issues.

Bdale
From: Mark_Geisert@l66a.ladc.bull.COM (Mark Geisert)
Newsgroups: comp.sys.nsc.32k
Subject: NS32GX32 pricing for ET532 board
Date: 4 Nov 92 20:57:00 GMT
Organization: Association for the Prevention of Polar Bears and Kangaroos

Here's some pricing info I received from Bell Industries, a NatSemi
distributor in California, in $US...
                QTY1-24     QTY25-99    QTY100-999
                -------     --------    ----------
NS32GX32U-20      90.00        78.50         71.00
NS32GX32U-25     100.00        91.00         83.00
NS32GX32U-30     120.00       105.00         95.00
 
BTW, this was the first Resale Schedule I've seen that didn't list
the '532.  NS32532, R.I.P.
 
..mark
From: wittb@nextnet.csus.edu (brian witt)
Newsgroups: comp.sys.nsc.32k
Subject: help: Need docs for Definicon 32032 board
Summary: Looking for hardware docs for Definicon 32032 board.
Keywords: 32032, Definicon Systems
Date: 9 Nov 92 04:07:59 GMT
Organization: California State University Sacramento, USA

Hello all --
At long last my Definicon Systems 32032 board is going to get some
workout!  However, I did purchase the board used, and received no
documentation.  I do have the UNIX filesystem and such for it, so
I can get some useful work done with the board.  However, I'm interested
in two items:
	1) what are the jumpers' meanings, and
	2) what is the hardware port interface like?
	3) any way to add more memory (board has 2 megs(?))

Does any one have any interesting details about this board?  Was
this the board featured in BYTE some number of years ago?

Specifically, the rev. C PCB has a 1985 copyright date on it, and uses
the [S8624] NS32032E-10/G processor.  Support chips are [S8608]
NS32082D-10/M, [S8536] NS32201D-10, and [S8628] NS32081D-101/F.  I've
seen this bord run UNIX, so I know it works.  The EEPROM is also
programmed correctly.  Are these "good" chip revision steps?
Does the CPU have an errors?  Does this MMU have boundry troubles?

What I'd like to do in January is perhaps force Mach onto this board.
I'm interested in operating system research stuff (home consumption,
mind you :-).  Hopefully the 32032 Mach will be talking to the 80386
Mach running on the host...

All pointers are welcome!  Is beowulf still archiving?
I realize most everyone is running that awesome PC-532 machine, but
hey, this is what I got!  I also have the 32016/32032 Designer Kit
from N.S. through in as extra, so I'm not without chip docs.

(For email replies, use wittb@babbage.ecs.csus.edu rather than nextnet)

--- tanks in advance
--- Brian Witt   (wittb@babbage.ecs.csus.edu)

-- 
======================================================================== !
   Brian Witt     [Sac State Comp Science]   "Waldo, the pariot, is dead"
   Internet:  wittbj@cube01.ccs.csus.edu               -- Agent Cooper
                  #define  POSIX_ME_HARDER     1      <-- GNU
Newsgroups: comp.sys.nsc.32k
From: phil@cs.wwu.EDU (Phil Nelson)
Subject: bsd 4.4 port for pc532
Reply-To: phil@cs.wwu.edu
Organization: Association for the Prevention of Polar Bears and Kangaroos
Date: Wed, 11 Nov 1992 00:31:11 GMT


Yes, getting a port of 386bsd-0.1 would be a great thing to do.  I have
actually played with 386bsd (on a pc for 1 week) and I have the sources
on my pc532 (under Minix) and have looked at them.  Before I could be
very aggressive toward getting the kernel running, I needed several things
working under minix.  Here was my partital list . . .

  a) gcc with gas, gld, ...   (I now have it working,  up to gcc-2.2.2.
	gnu ar and ranlib "required" me at add a system call to minix.
	That system call was truncate/ftruncate. )

  b) Some of the Net-2 utilities, pmake, and other tools used in the 
	making of the kernel/utilities.  (I have many of those running.)

  c) Some way of creating, checking, and copying files to a BSD file
	system.  This would have to include mkdir, mknod, newfs, and
	fsck.  (To date I have newfs, fsck, and mknod working.
	mkdir is almost working in every case.  Copying files from a
	minix partition to the BSD partition is still not started.)

  d) Support for the BSD disklabel on disks and a way to boot a new
	kernel (Supported by my hdsetup program and autoboot monitor.)

  e) Make sure that standalone programs can be created and loaded
	to a boot partition using the GNU compiler and binutils.
	(Done just this week.  GNU ld did not generate a correct
	minix a.out file that the hdsetup program recognized.
	That is now corrected.)

  f) I have also discovered that to really have the makefiles as configured
	work under minix for 386bsd/net-2, minix needs to support at least
	30 character file names and symbolic links.  (I have neither on
	my version of minix.)

  g) I also need a way to generate BSD executables under Minix.  This
	means a complete separate library, include structure, ....
	These programs could not be tested under minix, but only copied
	to the BSD partitions.  (I have none of this done yet.)

  I will continue to slowly work on getting my system up to the place where
I can work on getting a "532BSD" up and working.  I am willing to help
where I can and I will continue to try to "upgrade" my Minix to make
it possible to do a full build for "532BSD."

  I understand that Mach is running reasonably well on the pc532 and that
when it was being distributed, BNR2SS (single server from the Net2 tape)
started to work.  I have similar problems to try to compile Mach and 
the BNR2SS under Minix.

  We will someday get BSD for the pc532!  (I hope!!!!)

--Phil


Newsgroups: comp.sys.nsc.32k
From: hoffberg@medusa.aps.anl.gov (Mike G. Hoffberg)
Subject: Anybody want dead HP-41's? or how to fix them
Summary: how to fix the bad display on the HP41
Organization: Argonne National Laboratory, Chicago Illinois
Date: Tue, 10 Nov 1992 22:20:43 GMT

I don't blame anyone for this, but I was not one of the people who got
one of the dead HP41s.  I just wish that I had the time to read
comp.sys.handhelds 24 hours a day, so that I could respond more
quickly.

A couple of years ago I got an original HP-41C from a friend.  He
basically said that if I could fix it, it was mine.

The problem was that the display was intermittant, the CPU seemed to
be fine.  I knew that it was a loose connection, but I had no idea
where.  The symptoms were that of a cracked trace, but none was to be
found.

Finally I got so fed up with the beast that I sat down one day and
said to myself that I would fix it (or break it beyond repair).  So, I
take out my trusty multi-meter, and prepare to start measuring
continuity.

The first step was to take out the batteries, then I pryed off the
rubber feet and removed the four screws.  The machine was now apart,
waiting for me to do my magic.

I sat there staring at the circuit board wondering where to begin...
I knew the problem was with the display, so I started with the foil
wires that connected the LCD module with the main board.  The first
one seemed OK, same with the second, on the next couple I found the
problem.  Over the years, the poor solder joints had loosened up.  All
that was required to fix the calculator was to reflow the solder, and
replace the screws which were now somewhere on the workbench.

When that was done, I had a working calculator.  I was happy, it was
one of the first pieces of equipment that I fixed using those four
valuable years of EE education, as well as countless hours of hobbying
:)

So, if anyone has any "dead" HPs, contact me, I would like them.

MIKE
-- 
Michael Hoffberg               /.\ <Build APS>   ~\   /~  "Jeez, am I the
hoffberg@phebos.aps.anl.gov   // \\ Argonne        \ /     only one who paid
hoffberg@anlaps.aps.anl.gov  //_O_\\ National       |      full price?" F.F.
                            /__| |__\ Lab   Obbyn! _|_ Obbyn!
From: m14494@mwvm.mitre.org (Mike White)
Newsgroups: comp.sys.handhelds
Subject: Sharp Wizard 8000 wanted
Date: 6 Nov 92 14:44:06 GMT
Distribution: na
Organization: The MITRE Corporation

A few days ago, someone posted a Wizard 8000 for sale, but I lost the
message.  If it's still available, or if you've got one you'd like to
let go of, please email.  Thanks.

************************
* These are my opinions only.*
************************
From: akcs.ddd@hpcvbbs.cv.hp.com (Don Davis)
Date: Wed, 11 Nov 1992 21:40:02 GMT
Subject: User's Groups
Message-ID: <2b016fa7.4974comp.sys.handhelds@hpcvbbs.cv.hp.com>
Newsgroups: comp.sys.handhelds

Does anyone have information on an HP calculators user's group in the
Atlanta, GA area? I'd be interested.
From: akcs.rbutler@hpcvbbs.cv.hp.com (Ralph Butler)
Newsgroups: comp.sys.handhelds
Subject: Forsale HP 75C
Date: 7 Nov 92 17:40:02 GMT

I have an HP 75C forsale, including a Reference Manual and an 
Owner's Manual, HP-IL cable (5m), AC power adaptor, and some 
mag strip application programs.  Make an offer.  Thanks.
Ralph Butler 602-862-4158
r.butler@az05.bull.com
From: akcs.alistairl@hpcvbbs.cv.hp.com (Alistair S Lang)
Date: Thu, 5 Nov 1992 21:40:03 GMT
Subject: SHAPE MEMORY ALLOYS
Message-ID: <2af98775.4953comp.sys.handhelds@hpcvbbs.cv.hp.com>
Newsgroups: comp.sys.handhelds
Keywords: shape memory alloys heat engines

This has *nothing* to do with my HP48 but as this is the only Bulletin
Board that I know, I thought I'd post this here:

Currently I'm studying Mechanical Engineering at the University of
Strathclyde in Glasgow, Scotland and my fourth year project is to analyse
the performance of shape memory alloys (SMA's) and to develop a small
power generation unit utilising their characteristics.

I would like as much information as possible on existing SMA heat engines
from anybody who can supply it.

I believe the Lawrence Berkeley Laboratory at the University of
California demonstrated the first successful application of SMA's to a
continually operating heat engine in August 1973. After that various SMA
studies, including heat engines, were initialised at LBL principally
under a grant from the National Science Foundation/RANN.

Are these studies continuing today?

What are the current maximum power outputs from these engines?  My
project has been "initiated" by the Ford Motor Company and they suggested
a possible goal of 10 watts - rather optimistic in my opinion!

The only books that I have access to are:
Engineering Aspects of Shape Memory Alloys by T W Duerig et al 1990   and
Shape Memory Effects in Alloys by J Perkins 1975  (source of the above
information).

Any information would be greatly appreciated.

Thanks!

A.S.Lang
Newsgroups: comp.sys.handhelds
From: brianw@iat.holonet.net (Brian Walsh)
Subject: Re: Does PPC still exist?
Organization: HoloNet
Date: Wed, 11 Nov 1992 00:46:26 GMT

akcs.robertson@hpcvbbs.cv.hp.com (Glenn Robertson) writes:
: Mark,
: PPC has been resurrected!  Their BBS number is (310) 978-0024
: Glenn
: 
That's the BBS Richard Schwartz started several years ago before PPC ceased.
Newsgroups: comp.sys.handhelds
From: tlspurli@athena.mit.edu (Terry Spurling)
Subject: HP calc for sale
Organization: Massachusetts Institute of Technology
Distribution: usa
Date: Thu, 12 Nov 1992 05:43:19 GMT

Rev E HP48sx calc for sale
Owner's manuals
Soft case
Some software(including ->ASC and ASC->) installed

$200 +shipping from MIT in Boston price is negotiable, shipping is not!
I need to get rid of it before I leave on the 20th.
terry spurling
tlspurli@athena.mit.edu

Also I have a homebrew cable with a female RS-232 connector on the end and all
original manuals that came with the calculator.
From: akcs.gazza@hpcvbbs.cv.hp.com (Jack Dermody)
Newsgroups: comp.sys.handhelds
Subject: why is chat never availlabk [Dle?
Date: 11 Nov 92 18:40:01 GMT
Article-I.D.: hpcvbbs.2b014d4e.4973comp.sys.handhelds

i have signed on 5 times and chat is never availlable.Please write back
and explain what is wrong?
From: akcs.robertson@hpcvbbs.cv.hp.com (Glenn Robertson)
Date: Tue, 10 Nov 1992 13:40:02 GMT
Subject: Re: Does PPC still exist?
Message-ID: <2affbaf4.4957.1comp.sys.handhelds.1@hpcvbbs.cv.hp.com>
Newsgroups: comp.sys.handhelds

Mark,
PPC has been resurrected!  Their BBS number is (310) 978-0024
Glenn

Xref: sparky comp.sys.handhelds:2373 comp.sys.palmtops:3569
From: anthony@csd4.csd.uwm.edu (Anthony J Stieber)
Newsgroups: comp.sys.handhelds,comp.sys.palmtops
Subject: Re: Gateway 2000 Handbook Information
Date: 10 Nov 92 01:06:32 GMT
Distribution: inet
Organization: Computing Services Division, University of Wisconsin - Milwaukee
NNTP-Posting-Host: 129.89.7.4

In article <swood.721350721@vela> swood@vela.acs.oakland.edu (Scott Wood - EVENSONG) writes:

>Processor:		C & T 286-class (NEC V30???)

It's a C&T 8680 which is basicly a fast Intel 8086 (or NEC V30).  It
may have the extra 80286 real mode instructions like the V30.  It is
not in any way a 80286 compatible processor (no protected mode, no
extended memory).  MS-Windows will only run on it in real mode.  No
version of OS/2 will run on it.  The use of the term "286-class" is
really misleading, unfortunatly I see more and more companies using it
to mean "speed of at least a slow 286 and nothing more".  Still, the
machine has good performance, better than other palmtops.

>Suggested Retail:	$1295

Note that this is also the only price since Gateway 2000 gives no
discounts and does all sales direct to the user.
--
<-:(= Anthony Stieber	anthony@csd4.csd.uwm.edu   uwm!uwmcsd4!anthony
From: akcs.tsblue@hpcvbbs.cv.hp.com (Thomas Stewart Blue)
Newsgroups: comp.sys.handhelds
Subject: Re: Iterations on HP-48? Mail-order places?
Date: 12 Nov 92 15:40:02 GMT
Article-I.D.: hpcvbbs.2b02720e.4952.1comp.sys.handhelds.1


Iterations.................I believe not, at least not directly
It would be fairly simple to write a routine to perform iterations,
however. This would be especially true if you have the equation sover
card.

Cheapest 48/48sx price i've seen: Surveyor's Supply (Apex, NC)

Cheapest 48/48sx accessories I've seen: Educalc (Laguna Nigel, CA) (I
believe)

tsblue@eos.ncsu.edu
From: akcs.suzanne2@hpcvbbs.cv.hp.com (suzanne smith)
Newsgroups: comp.sys.handhelds
Subject: Re: Stuff For Sale
Date: 5 Nov 92 22:40:03 GMT

I am looking for an HP-IL interface card to connect an HP-41CV to a PC.
Will your HP-95 Connectivity Pack fill that bill do you think.  What 
are you asking for the item? S. Smith, P.O. Box 2124, South Hackensack,
New Jersey 07606.
Newsgroups: comp.sys.handhelds
From: twh18@isuvax.iastate.edu (Phoenix)
Subject: Re: Anybody want two dead HP-41's?
Reply-To: twh18@isuvax.iastate.edu
Organization: Iowa State University, Ames, Iowa
Date: Thu, 12 Nov 1992 03:50:09 GMT

In article <2afffdc2.4965.2comp.sys.handhelds.1@hpcvbbs.cv.hp.com>, akcs.levenson@hpcvbbs.cv.hp.com (william j. levenson) writes:
>Wow!  I didn't know that there was such a demand for dead HP-41's.  Mine
>has been spoken for.  Thanks for the responses.
>
>Bill levenson
	I thought that you guys said HP's are pretty tough macine.....
Is HP-41 a exception:)?	
				Ming
	(just wondering, I heard HP's are build like tanks, or was that
regarding to HP48SX only?)
From: bobc@natinst.com (Bob Conyne)
Newsgroups: comp.sys.handhelds
Subject: HP-41 stuff for sale
Date: 11 Nov 1992 17:23:11 -0600
Organization: National Instruments, Austin, TX
Distribution: inet
NNTP-Posting-Host: eagle.natinst.com
Summary: 41 ROMs, books, etc for sale

I keep seeing posts regarding the HP-41, so I guess there is hope that
someone might be interested in purchasing some HP-41 stuff I have.  I traded
in my HP-41 for a 48SX from EduCalc, and I still have several 41 add-ons, all
in excellent working condition, with manuals:

ROMs:    Time Module (with manual and "Time Module Solutions" book)
         Advantage Module
         EE module
         PPC ROM

Books:   "Expand your HP-41" by W. Mier-Jedrsejowicz  (> 600 pages!)
         "Inside the HP-41" (41 machine language)

Also:    80 Mag cards for the card reader
         N-cell recharger w/ 2 sets of batteries (8 total) -- works great!
         Several program listings w/bar code from the program library

All in a very handsome briefcase!  (Actually, the briefcase is beat to hell,
but still functional).

I'd be thrilled if someone offerred $75 for this stuff, but I will take any 
reasonable offer.

Email me at bobc@natinst.com if you are interested.
--Bob