Info-IBMPC@WSMR-SIMTEL20.ARMY.MIL ("Info-IBMPC Digest") (11/18/90)
Info-IBMPC Digest Sun, 18 Nov 90 Volume 90 : Issue 186
Today's Editor:
Gregory Hicks - Rota Spain <GHICKS@WSMR-Simtel20.Army.Mil>
Today's Topics:
filehandles (7 msgs)
Re: SLOW memory check
Re: Low Level Format of 7080AT Hard Disk
Today's Queries:
Contour map algorithm
Problem with Token ring....
Tandy 2000 HD ==> AT&T PC6300 ???
WP Graphics and MATLAB
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Date: Tue, 6 Nov 90 09:52:30 +0100
From: bax%TUDGW2.TUDELFT.NL@uga.cc.uga.edu
Subject: filehandles
>Date: Tue, 6 Nov 1990 07:38:50 MET
>From: "W. Felscher" <mife001@MAILSERV.ZDV.UNI-TUEBINGEN.DE>
>Subject: filehandles
>To: Multiple recipients of <RED-UG@HEARN.BITNET>
>
>
>1. Assume that "program" is small, auxiliary program running in
> a batch file. Assume that it produces a short screen output
> which you want to suppress. Calling it with
> program > nul
>
> indeed suppresses said output.
>
> But it also decreases the number of filehandles available. If
> other programs, started at some later stage, require a minimum
> number of open file handles, these may not be available. Of
> course, an obvious way out is to reboot such that config.sys
> again exerts its effect.
I have a question about this. Doesn't command.com free the handle that
was used for "nul" after the program ends? Besides, does command.com
really use a new handle for redirection? I was convinced that standard
output always uses handle number 1. And that filehandles are freed
after termination of the program in which they were opened. Can someone
let his light shine on this?
Arjen Bax.
Ir. Jan A. Bax Phone: +31-15-782501
Delft University of Technology, Faculty of Geodesy
Section of Physical, Geometric & Space Geodesy
Thijsseweg 11, 2629 JA Delft, The Netherlands
E-mail: gdsgste@hdetud1.bitnet; bax@tudgw2.tudelft.nl
------------------------------
Date: Tue, 6 Nov 90 21:19:00 N
From: Felix Geerinckx <FEELG%PHS.UIA.AC.BE@uga.cc.uga.edu>
Subject: filehandles
Walter Felscher wrote:
> [stuff deleted]
>2. Questions:
>
> a) is there another way than this simple redirection to nul
> which prevents screen output and does NOT decrease the number
> of filehandles ?
I thought that the NUL device is on of the five files that is always
open in MS-DOS. B.t.w. the file to which output is redirected is
closed after the redirection operation, so its handle is released and
made available for re-use.
> b) is there a software which (i) without a reboot sets a new
> (larger) number of open filehandles and (ii) preferably can
> be called in a batchfile ?
Since space for file handles is allocated during boot-up, I don't think
you can enlarge this area. But why not put a "files =
more_than_enough" with more_than_enough >= 40 in you config.sys? It
doesn't require that much memory.
-felix (feelg@phs.uia.ac.be or FEELG@BANUIA51.Bitnet)
------------------------------
Date: Wed, 7 Nov 90 09:37:04 +0100
From: bax%TUDGW2.TUDELFT.NL@uga.cc.uga.edu
Subject: filehandles
> Date: Tue, 6 Nov 1990 21:23:44 MET
> From: Felix Geerinckx <FEELG@PHS.UIA.AC.BE>
>
> I thought that the NUL device is on of the five files that is always
> open in MS-DOS. B.t.w. the file to which output is redirected is closed after
> the redirection operation, so its handle is released and made
> available for re-use.
I don't completely agree with this. The always open files in ms-dos are:
handle 0: standard input (redirect with <)
1: standard output (redirect with >)
2: standard error (the console)
3: auxiliary device (usually AUX or COM1)
4: printer device (PRN or LPT1)
One *may* redirect standard output to the NUL device. It is not the
device that is open, but the handle.
But I *do* agree that used file handles are returned to the pool after
a file is closed or the program that opened it, ends.
Arjen Bax.
Ir. Jan A. Bax Phone: +31-15-782501
Delft University of Technology, Faculty of Geodesy
Section of Physical, Geometric & Space Geodesy
Thijsseweg 11, 2629 JA Delft, The Netherlands
E-mail: gdsgste@hdetud1.bitnet; bax@tudgw2.tudelft.nl
------------------------------
Date: Wed, 7 Nov 90 13:02:28 LCL
From: "Thomas Greve, PI Bonn" <GREVE%DBNPIB5.BITNET@uga.cc.uga.edu>
Subject: file handles
To answer this question:
If a program terminates with INT 21, AH=0 or AH=4ch or with INT 20,
*all* opened files are closed and all handles are freed. So you can use
> NUL for any program you like without problems.
Ok. Almost:
If a program terminates and stays resident, opened files remain opened
and used file handles remain used. So don't stop your mouse driver's
mouth with mouse > NUL. You will loose one NUL handle then. If you
*have* lost handles this way, you can free them again. In one of the
last c'ts it was published, how. Thomas
------------------------------
Date: Wed, 7 Nov 90 14:19:00 -0330
From: noelroy%KEAN.UCS.MUN.CA@uga.cc.uga.edu
Subject: filehandles
Date: Tue, 6 Nov 90 09:52:30 +0100
From: bax@TUDGW2.TUDELFT.NL
I have a question about this. Doesn't command.com free the handle that
was used for "nul" after the program ends? Besides, does command.com
really use a new handle for redirection? I was convinced that
standard output always uses handle number 1. And that filehandles are
freed after termination of the program in which they were opened. Can
someone let his light shine on this?
Arjen Bax.
My experience is that COMMAND.COM does free the handle to the NUL
device after the program ends. However, if the program is a TSR, the
program never ends. So you can get this cascading of open NUL handles,
if you redirect the output of several TSR's to NUL.
Dr. Noel Roy bitnet: NOELROY@MUN
Department of Economics internet: noelroy@kean.ucs.mun.ca
Memorial University of Newfoundland cdnnet: noelroy@kean.mun.cdn
St. John's, Newfoundland A1C 5S7 Canada
------------------------------
Date: Wed, 7 Nov 90 14:07:00 EST
From: Rick Beebe <BEEBE%YALEMED.BITNET@uga.cc.uga.edu>
Subject: filehandles
>>
>>1. Assume that "program" is small, auxiliary program running in
>> a batch file. Assume that it produces a short screen output
>> which you want to suppress. Calling it with
>> program > nul
>>
>> indeed suppresses said output.
>>
>> But it also decreases the number of filehandles available. If
>> other programs, started at some later stage, require a minimum
>> number of open file handles, these may not be available. Of
>> course, an obvious way out is to reboot such that config.sys
>> again exerts its effect.
>
>I have a question about this. Doesn't command.com free the handle that
>was used for "nul" after the program ends? Besides, does command.com
>really use a new handle for redirection? I was convinced that
>standard output always uses handle number 1. And that filehandles are
>freed after termination of the program in which they were opened. Can
>someone let his light shine on this?
I believe that, in a way, you are correct. My understanding was that
all programs (command.com included) automatically get five open file
handles: stdin, stdout, stderr, stdprn and nul(?) when they run.
Redirecting a program's output doesn't open a new handle, it merely
changes that program's stdout handle to point to nul. When the program
exits all the handles are closed anyway, so there shouldn't be any
adverse effects on subsequent programs. Notice what else that implies:
you can't suppress, via redirection, any program output that is sent to
stderr or stdprn.
When you redirect a program's output to a file, command.com opens that
file (creating it if necessary) and passes its file handle to the
program in place of stdout. When you exit, command.com closes the file
and releases its handle. Basically the same thing happens when you use
the < redirection symbol, except that the file must exist and stdin is
redirected instead of stdout.
Rick Beebe (203) 785-4566
Biomedical Computing Unit
Yale University School of Medicine
333 Cedar Street, New Haven, CT 06514
BEEBE@YALEMED.BITNET
beebe%biomed.decnet@venus.ycc.yale.edu
------------------------------
Date: Thu, 8 Nov 90 16:42:46 00100
From: P7MAI016%FRCIRP81.BITNET@uga.cc.uga.edu
Subject: Filehandles
Hello,
When a program starts, the five handles opened are stdin, stdout,
stderr, stdprn and **stdaux** not the nul device. so if you redirect to
nul, there is an open for NUL so maybe you lost an handle (I think it's
an old problem anyway). Now I 'm using 'CTTY NUL' and CTTY CON: it
works the same way without that particular problem; or maybe I'm wrong?
Best regards,
Ollivier
Ollivier ROBERT INTERNET: roberto@germinal.ibp.fr
Universite de Jussieu PARIS 7 BITNET: p7mai016@FRCIRP81.BITNET
PARIS, FRANCE
------------------------------
Date: Fri, 9 Nov 90 09:32:03 PST
From: ucsb.6600arac%ucsbuxa@hub.ucsb.edu
Subject: Re: SLOW memory check
I doubt your battery is dead, or dying already. One solution may
be to check your power cables and also your hard drive cables. Since
your memory is on an add-in board, try checking the contacts. Dirty,
or loose contacts could be at fault. Good luck
------------------------------
Date: Tue, 6 Nov 90 14:28:00 N
From: SURF023%KUB.NL@uga.cc.uga.edu
Subject: Re: Low Level Format of 7080AT Hard Disk
Franz ,
DO NOT LOWLEVEL FORMAT THE 7080 AT or you will probably destroy the
disk! The maxtor 7080 AT is probably a 7080 A from MiniScribe (no
longer present) There are two things on the 7080 you should know:
- Physical information
- Useable information
The physical information can NOT be used the drive does not support it.
You can use the useable information to format the disk (yes format not
LOW-LEVEL-FORMAT).
--- Physical Information
Heads : 4
Sectors : 36 by 512 Bytes
Cylinders: 1159
Cap.MB : 81.5 MB (85 Mil.Bytes)
--- Useable information for your Bios-setup
Heads : 10
Sectors : 17 by 512 bytes
Cylinders: 980
Cap.MB : 81.5 MB
To format the disk :
Setup computer with useable information. FDISK the disk (do not use
DiskManager) After FDISK your FORMAT the disk with DOS-FORMAT (use /s
on C: -partition) This is the way to do the formatting on a NEW 7080 A.
If you still have trouble send me a note OR send the harddisk to my
firm and we will format it for you (with DOS 4.01).
I use these disks in my own machines and I have no trouble what so ever.
(I hope you get the disk working)
Greetings
Rudi v. Dijck
The Netherlands
------------------------------
Date: Thu, 8 Nov 90 11:41:33 EDT
From: Ricardo Sanchez Carmenes <CMSMD11%EOVUOV11.BITNET@uga.cc.uga.edu>
Subject: Contour map algorithm
Hello netlanders:
I'd very much appreciate a hand/clue/pointer to find an algorythm
and/or routines to draw two-dimensional contour maps from
two-dimensional matrices of numerical data.
That is, given a two-dimensional matrix of real values (where each
datum might be considered as a point in a plane), and given a delta
value, it is desired to draw the lines that link the points
corresponding to (or interpolating between) integer multiples of the
delta value.
Or in simpler terms, the kind of algorythm useful to draw things
like isobares, contour maps, or in general, isograms or isolines.
This sounds to me as a classical problem, so I wouldn't like to
re-invent the wheel, but I couldn't find any reference about it in the
books on numerical methods, and the like, I have available.
A pointer to a description, or the description itself, of such an
algorythm would be appreciate. Source code in C, Pascal or Modula-2
also would be appreciated, but is not essential.
Thanks in advance to all.
Answers can be sent either directly to me or to the Digest, as you
prefer.
Ricardo S. Carmenes,
Departamento de Biologia Funcional,
Area de Bioquimica y Biologia Molecular,
Universidad de Oviedo, Oviedo, Spain.
Email: CMSMD11@EOVUVO11.BITNET or
CMSMD6@EOVUOV11.BITNET or
carmenes@dwarf0.quimica.uniovi.es (prefered).
------------------------------
Date: Fri, 9 Nov 90 19:51:22 MET
From: rol%grasp1.univ-lyon1.fr@CUNYVM.CUNY.EDU
Subject: Problem with Token ring....
Hi,
I've written a program in assembly language that works fine as
long as I've not typed the command :
Net start rcv .....
Once I've done that, my program crashes as soon as it must execute the
following:
Xor Dl,Dl
Mov Ah,47H
Int 21H
with I can't remenber which register pointing to the buffer in which to
store the result.
Could anyone explain me why it's always crashing ? I've tried to find
it with a debugger, but it crashes too as soon as i try to get into int
21H. Is it because of the stack (it's only 512 bytes long) ?
Paulo.
Rolland Paul - INSA de Lyon - Departement Informatique
Email : rol@grasp1.univ-lyon1.fr, rol@riri.univ-lyon1.fr
------------------------------
Date: Fri, 9 Nov 90 14:03:28 GMT
From: mdiehl%hydra.unm.edu@ariel.unm.edu (J. Michael Diehl)
Subject: Tandy 2000 HD ==> AT&T PC6300 ???
I have an old tandy 2000HD and an AT&T PC6300 with two floppy disks. I
would like to take the hard drive and controller out of the 2000 and
put it into the at&t. The tandy 2000 (IMHO) was a flaky little beast,
so I am hesitant to make the trade for fear of blowing my computer up!
WILL THIS WORK?
Thanx in advance.
J. Michael Diehl ;-]
mdiehl@hydra.unm.edu
Thunder@forum
Thunder@Tiny*
(505) 272-HaHa
------------------------------
Date: Fri, 9 Nov 90 13:16:39 EST
From: Charles Holden Winstead <winstead@faraday.ece.cmu.edu>
Subject: WP Graphics and MATLAB
Hello,
I am looking for a drawing program which reads wp5.1 graphic format,
*.WPG, and allows me to modify it; add text, lines,boxes etc. Any
Idea?
Also, I use a mathematical package called MATLAB, and haven't been able
to run the advanced version under windows 3. The machine reboots when
I try.
Thanks
Chuck
winstead@faraday.ece.cmu.edu
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End of Info-IBMPC Digest V90 #186
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