From: Info-IBMPC@WSMR-SIMTEL20.ARMY.MIL ("Info-IBMPC Digest")
Newsgroups: comp.sys.ibm.pc.digest
Subject: Info-IBMPC Digest V92 #206
Date: 29 Dec 92 12:23:48 GMT
Reply-To: Info-IBMPC@wsmr-simtel20.ARMY.mil
Organization: The Internet
X-Unparsable-Date: Sun, 27 Dec 92 22:24:28 GMT+1

Info-IBMPC Digest           Sun, 27 Dec 92       Volume 92 : Issue 206 

Today's Editor:
         Gregory Hicks - Rota Spain <GHICKS@wsmr-simtel20.Army.Mil>

Today's Topics:
                   286/386 Protected Mode Programming
                        FDFORMAT/FDREAD for OS/2
                                 fsplit
         Graphical tool for file maintenance over dialup links
                   Harvard Graphics Runtime Slideshow
                       Info-IBMPC Digest V92 #193
                            Kaypro to IBMPC
                       Max number of files in dir
                 Max. number of files in DOS-directory?
              Mixing 1M and 4M SIMMS...  Why not? (3 msgs)
                  Optimal settings for communications
            Real mode / Protected mode definition? (3 msgs)
                             screen savers
                          What HD to choose???
              IBM HelpLine Solved My Floppy Disk Problem!

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Archives of past issues of the Info-IBMPC Digest are available by FTP
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----------------------------------------------------------------------

Date: 19 Dec 92 03:25:35 GMT
From: ioi@widget.seas.upenn.edu (Ioi Kim Lam)
Subject: 286/386 Protected Mode Programming
Keywords: 286, 386, protected mode, operating system, multi-tasking

I am trying to do some protected mode programming using the 286/386
instruction set. My final goal is making a simple operating system with
preemptive multitasking capability.

I am looking for some example assembly programs, probably in MASM or
TASM syntax, for the 286/386 protected mode. An ideal example program
would be switching into Protected Mode form Dos, run several processes
preemptively and exit to Dos. I know some of you guys are really great
and have written a complete O/S for the 286/386. I really don't mind
seeing those codes.

Also, I am using TASM to compile my code. I am not sure if this is an
ideal tool for the purpose of developing an O/S. Do you have any
suggestion for an appropriate set of development tools? Is the Intel
Development Toolkit good?

If you have any suggestion for any further information, please mail it
to me. I am just a beginner to O/S programming but I would love to
share other people's experience. 

Thanks in advance!

------------------------------

Date: Sun, 20 Dec 1992 22:51 EST
From: "John K. Duchowski" <MORRO@drycas.club.cc.cmu.edu>
Subject: FDFORMAT/FDREAD for OS/2

Hello Everyone,

   Has anyone come across an OS/2 2.0 version of Christopher
Hochstatter excellent par of programs FDFORMAT/FDREAD ?  These programs
enable one to format floppy diskettes to higher capacity (DS/DD to 830
K for example !) on regular 1.2 M and 1.44 M drives.

The latest version that I've seen is 1.8 however, FDREAD does not
appear to run in any way shape or form under OS/2.  I've tried both
full screen and windowed versions of both DOS and OS/2 with the same
result - some gibrish scrolling across the screen and not much else.
There are no error messages or anything, but I still can't read the
FDFORMATed diskettes.

I am a bit desperate as I have a lot of these 830 K and 1.77 M floppies
but because I went to OS/2 and HPFS only system I have no easy way of
reading these.  If anyone has a knowledge of newer version of these
programs or perhaps knows how to reach Mr. Hochstatter himself (I would
be willing to work on porting these to OS/2, if necessary), I would
very much appreciate hearing about it.  Thanks in advance for any and
all help.

Best Regards to All,
John Duchowski

------------------------------

Date: Mon, 21 Dec 92 10:07:22 EST
From: Jeffrey Marans <jeff@erie.irc.nrc.ca>
Subject: fsplit

Has anyone seen a pd dos utility like the unix fsplit program?  I
looked around the mirrors but only saw the bsd version which doesn't
compile with MS C.

Jeff Marans
jeff@erie.irc.nrc.ca

------------------------------

Date: Wed, 16 Dec 92 20:30:04 EST
From: Benjamin Olasov <olasov@ground.cs.columbia.edu>
Subject: Graphical tool for file maintenance over dialup links

Perhaps the some of the well informed recipients of this list will have
some insights into this issue, which may possibly be a concern for
others.  There are computer accounts I access in most cases with a
dialup link using VT100 emulation.  I keep wishing for a tree-
structured point-and-shoot utility for doing file and directory
maintenance from a remote terminal.  Does someone know of such a tool
for either DOS or Unix?  Perhaps our friends at FSF have come up with
something along these lines?

Thanks,
 
Ben Olasov
olasov@cs.columbia.edu

------------------------------

Date: 17 Dec 92 18:34:00 CST
From: 43MWRSSMWFL <43MWRSSMWFL@strathost.stratcom.af.mil>
Subject: Harvard Graphics Runtime Slideshow

Hello NETLAND ... and MERRY CHRISTMAS

I would like to distribute charts prepared in Harvard Graphics to users
NOT having Harvard.  Does anyone know of software that will display the
said charts, slideshow fashion?  Either shareware/freeware/commercial
products are acceptable.

James Drew
internet:  43MWRSSMWFL@strathost.stratcom.af.mil

------------------------------

Date: Mon, 21 Dec 92 15:13:51 SAT
From: Nasir Haniffa <ACDH083%SAUPM00.BITNET@VTVM2.CC.VT.EDU>
Subject: Info-IBMPC Digest V92 #193

    We have a BBS  running Pcboard 14.5b in our office to the public.
It is a free BBS. We are planning to Have a NetWork mail connecting our
BBS to any available net. I was told that Fidonet is a better choice
for it.

 But I do not have any idea on what to do and where to look for info.
I have my BITNET account and I am recieving mails through it as I do
now..

 Can some one tell how to join our PC to Fidonet through BITNET?  Is
there any software that does the job? Where can I lokk for info.
Please.. Thanks in advance,...

 Personal mail reply will not mess this list.. :)

 Our BBS number is 966-3-8332082 ( SAUDI ARABIA )
 Nasir ( ACDH083@SAUPM00.BITNET)

------------------------------

Date: Fri, 18 Dec 92 10:07:31 MET
From: Jim Groeneveld CMI-TNO Leiden NL <groeneveld@cmi.tno.nl>
Subject: Kaypro to IBMPC

Dear Todd,

Concerning your Q in IBMPCL92.190 I can point you to a program
CONVERT.EXE that should do the job as shown below (extracted from the
program). It's size is about 30kb. I can not send you a copy. It's
commercial (from the time PD and SW still weren't so popular yet).
Contact the address below or the authors themselves. Maybe they have
even newer versions.

- - - - - - - - (extracted from the program) - - - - - - - -
CONVERT 1.26  Copyright(c) 1983, 1984 by Selfware, Inc.
Written by: Charles W. Woodford and John P. McGowan

Purchased from:            The Software Specialist
                           1625 K Street, NW
                           Washington, DC  20036
                           (202) 467-5727
                           "Washington's Computer Speciality Store"

CONVERT is sold for use on a single computer.  We trust you to not make
illegal copies for other computers or your friends.

CONVERT gives owners of PC-alike computers the ability to read and
write files and format diskettes for many CP/M systems.  It will move
programs and data files from system to system but it will NOT translate
8080 or Z80 programs to run on an 8086 or 8088 computer.

You may do any of the following functions:

                  C    Copy files between CP/M and MS-DOS formats.
                  D    Display the directory of a CP/M diskette.
                  E    Erase (delete) a file on any drive.
                  F    Format a CP/M diskette.
                  X    Exit from the CONVERT program.
                  S    Select the CP/M diskette type.

You may read, write, and format any of these diskettes, with the exceptions
listed below:

 A - Access Matrix 9 ss   B - Columbia CP/M-86     C - Cromemco double s
 D - DEC VT-180           E - Epson Valdocs CP/M B F - Epson CP/M Version A
 G - HP-125 double sided  H - IBM or Chameleon ss  I - IBM or Chameleon ds
 J - Kaypro 2             K - Kaypro 4 or 10       L - LNW single sided
 M - Morrow single sided  N - NCR Decision Mate 5  O - NEC PC-8000 or 8800
 P - Osborne double dens  Q - Otrona               R - Radio Shack Mdl 4
 S - Sanyo MBC-1000/1150  T - Superbrain 20 (Jr.)  U - Superbrain 30
 V - Systel dbl sided     W - Televideo 802        X - Toshiba T-100
 Y - Xerox 820 double d   Z - Zenith Z-100 ds      [ - Zorba 7 double den

CAUTION!!  You can read Zorba and Kaypro 4 type diskettes only if the
diskettes were formatted using CONVERT.

Cromemco diskettes must be formatted by a Cromemco machine AND then
reformatted by CONVERT, no kidding!

Toshiba diskettes can not be formatted correctly by CONVERT.

DEC VT-180 type diskettes can be read by the DEC Rainbow.
- - - - - - - - (end of extraction) - - - - - - - -

I hope this may help you,

Regards - Jim.

P.S. If you have both a Kaypro and an IBM (compatible) isn't it
possible then to transfer files serially?

Centrum voor Medische Informatica TNO       <Email>              |  |  |\/|
TNO Center for Medical Informatics | GROENEVELD@CMI.TNO.NL  |  \_/  |  |  |
( CMI-TNO )    | Y. Groeneveld     | GROENEVELD@CMIHP1.UUCP | Jim Groeneveld
P.O.Box 124    | Wassenaarseweg 56 | GROENEVELD@TNO.NL      | Schoolweg 14
2300 AC Leiden | 2333 AL Leiden    |                        | 8071 BC Nunspeet
Nederland.     | (+31|0)71-181810  | Fax (+31|0)71-176382   | 03412-60413

------------------------------

Date: 21 Dec 92 08:27:00 EST
From: "Jay Morris" <MORRIS@patrick-pims.af.mil>
Subject: Max number of files in dir

>From: John Fauerbach <fauerbac@ivy.cs.unca.edu>
>Subject: Max. number of files in DOS-directory?
>
>devosa@research.ptt.nl (Aart de Vos) writes:

>: "What is the maximum number of files that can be stored 
>:  in a MS-DOS directory?"
>: 
>: Aart de Vos (A.deVos@research.ptt.nl)
>
>As far as I know, only the root directory has a maximum number on it.
>I think it is something like 128 files.  BTW, I notice that the father
>I went over about 128 files in a subdirectory, the slower it took to
>load a file.
>

Under 3.?, I believe the max was 111.  Under DOS 5.0, I saw a drive
that was well over 150 file before I straightened the guy out. (Why
souldn't I put all my data files on c:\ ?)

BTW, thats different.  I usually hear drives refered to as a mother.

Jay E. Morris                         * Bad boys and girls don't get lumps  
morris@patrick-pims.af.mil            * of coal for Christmas. They get  
jmorris@tecnet1.jcte.jcs.mil          * underware!  (And so do very naughty
DSN: 467-7454                         * big girls, but that's another story.)
CIS:73007,3107                        *                                       

------------------------------

Date: Fri, 18 Dec 92 17:51:58 EST
From: Gregory Hicks - Rota Spain <ghicks@BRL.MIL>
Subject: Mixing 1M and 4M SIMMS...  Why not?

Timothy/Al:

I ask this because I'm confused..  (Also because I don't
want/can't/haven't figured out how to post an original message from
BRL's rn yet)

The FAQ that Timothy maintains states '...don't mix these SIMMS'
(para-phrasing mine).  Why?  I just received 16M of 4M SIMMS (70ns
since I have a 486/50 and the 70ns was originally installed in my
machine), removed the SIMMS in bank 1 of an AMI motherboard and plugged
in the 4 new SIMMS.

OS/2 APPEARS to be running OK.

I understand that you shouldn't mix memory types in the same bank, but
...

Timothy, perhaps you might consider adding to the FAQ what the
consequences are of mixing different sizes of SIMMS.  I'll say this,
OS/2 seems to like the 20M of memory much more than it liked the
original 8M...  (The "buy more memory light" on the front of the
computer doesn't flash as often as it used to do.  WHAT?  you don't
have a "buy more memory" light installed?  Take a look at one side or
the other of your keyboard lock.  It should have an icon of a hard disk
somewhere very near it.)

Anyway...  I look forward to your comments.

Best,
Gregory Hicks
Editor, Info-IBMPC Digest

------------------------------

Date: Fri, 18 Dec 92 18:13:45 -0500
From: adhir@anywhere.umd.edu
Subject: Mixing 1M and 4M SIMMS... Why not? 

 From SMOKE.BRL.MIL you write:

-->I ask this because I'm confused..  (Also because I don't
-->want/can't/haven't figured out how to post an original message from
-->BRL's rn yet)

-->The FAQ that Timothy maintains states '...don't mix these SIMMS'
-->(para-phrasing mine).  Why?  I just received 16M of 4M SIMMS (70ns
-->since I have a 486/50 and the 70ns was originally installed in my
-->machine), removed the SIMMS in bank 1 of an AMI motherboard and plugged
-->in the 4 new SIMMS.

-->OS/2 APPEARS to be running OK. 

You shouldn't have any problems with 4 4meg and 4 1 meg simms as far as
I know.  The non simm mixing rule normally applies to varying speeds
and/or 3 chip vs 9 chip simms.  I am planning on purchasing 4 4 meg
simms soon and intent to have 20 megs ram when added to the 4 1 meg
simms in bank two...just like you have yours set up.  Don't worry about
it.

Al

------------------------------

Date: Fri, 18 Dec 92 19:26:43 EST
From: Gregory Hicks - Rota Spain <ghicks@BRL.MIL>
Subject: Mixing 1M and 4M SIMMS... Why not?

>Date: Fri, 18 Dec 92 18:13:45 -0500
>From: adhir@anywhere.umd.edu

>You shouldn't have any problems with 4 4meg and 4 1 meg simms as far
>as I know.  The non simm mixing rule normally applies to varying speeds
>and/or 3 chip vs 9 chip simms.

Ok...  Got it (I think).  I have 4-4 meg simms (9 chip) and 4-1 meg
simms (3 chip) installed.  The 3 chip, 1 meg simms in bank 0, the 9
chip, 4 meg simms in bank 1...  All 70ns ...  (I had to go home and
check to see WHAT was installed, where...)

Again, why not mix the different sizes? 

(And I really don't mean to be facetious or belabor the point, but I'm
trying to figure what COULD happen.  Am I setting myself up for trouble
later on?)

------------------------------

Date: 21 Dec 1992 11:09:11 -0500 (EST)
From: Howard Kaplon - Towson State University <E7M2KAP@toe.towson.edu>
Subject: Optimal settings for communications

In reference to problems with Kermit 3.11 DOS version.   There have
been patches to correct some problems.   I have a patch dated November,
1991.  If you do not have this patch, you can contact me directly, or
try the people at kermit.   I think I have an E-Mail address somewhere
under a pile of papers.

Howard Kaplon

------------------------------

Date: 16 Dec 92 19:56:03 GMT
From: Malcolm Sharp <sharp@mizar.usc.edu>
Subject: Real mode / Protected mode definition?

I'd appreciate someone providing a definition of real mode and
protected mode.  I thought I understood the difference - until I needed
to explain it someone.  I looked in the MS-DOS 5.0 manual and found
nothing.  Is this something that usually involves Windows only?  The
question came to me from someone who just bought a new compiler that
said he could compile either for real or protected mode.

Thanks in advance.
Malcolm Sharp

------------------------------

Date: 17 Dec 92 01:02:17 GMT
From: Dennis Marer <dmarer@td2cad.intel.com>
Subject: Real mode / Protected mode definition?

sharp@mizar.usc.edu (Malcolm Sharp) writes:
>I'd appreciate someone providing a definition of real mode and
>protected mode.  I thought I understood the difference - until I
>needed to explain it someone.  I looked in the MS-DOS 5.0 manual and
>found nothing.  Is this something that usually involves Windows only?

Ok, I'll bite... (and have time on my hands...)

Think of 'real mode' as how the original 8086's, 8088's and 80186's
ran: every segement:offset address corresponded exactly to a physical
address in memory.

	0001:0000h = 0000:0010h = address 00010h in memory

In protected mode, each 'task' has its own view of the machine.  Each
task also can use global data segments (found in the global descriptor
table, or GDT) or local data segments (found in the LDT).  Segments in
protected mode actually point to the descriptors in one of these
tables, and the descriptors actually contain the physical address.
This changes the following:

	0001:0000h is probably NOT equal to 0000:0010h!!!

In this way, tasks can use global segments (from the GDT) or local
segments (from the LDT).  If a segment loaded into CS,DS,ES,SS,... is
NOT found in the GDT or the LDT, a violation occurs because the CPU has
no way to translate the segment into an actual phsyical address via
descriptors.  Another note is that two tasks may have the same segment
in their LDTs pointing at different physical memory addresses!

Another feature of protected mode on the 386 and up: The offset can now
be 32-bits giving each segment a 4GB ceiling (compared to the previous
64K).

If your environment uses virutal memory, then the physical addresses
stored in the descriptors are actually indeces into another virtual
memory lookup table.  This extends this memory size (from the task's
point of view) to >30 terabytes.

You can also run a 'virtual 8086' task within protected mode, which is
how OS/2 can emulate a DOS machine so well...in fact, MS-DOS 5.0 is
running inside a virtual 8086 task inside protected mode!  So MS-DOS
does use protected mode, but there's no reason why your programs need
to know this.  They'll run the same as if they were on a good old PC...
:-)

				Dennis Marer
				dmarer@td2cad.intel.com

-- Not speaking for Intel

------------------------------

Date: 17 Dec 92 02:38:22 GMT
From: francis@ac.dal.ca
Subject: Real mode / Protected mode definition?

The number of address lines the microprocessor can use depends on the
mode the PC is running in.

The 8086 only had one mode, and in it all 20 address lines are active
(giving it 2x10e20, or 1Mb RAM access).

The '286 (24 address lines=16Mb RAM), '386 & '486 (32 address lines=4Gb
RAM) can use all of their address lines, but only when they are running
in *protected mode*.  DOS does not run in protected mode; DOS will only
run in these processors' *real* mode, which emulates an 8086.  In real
mode, only the first 20 address lines are active.  A 286, 386 or 486
running in real mode (running DOS) is limited to 1Mb of memory, just
like an 8086.

The 386 and 486 support a third mode called *virtual 86 mode*, which is
similar to real mode, except that it is possible for DOS to gain access
to more than 1Mb of memory because of the quirks of virtual 86 mode.
When run in protected mode, each program can be allocated a certain
section of memory, which other programs cannot touch, hence the name
"protected mode."  PM also allows the use of extended memory, virtual
memory and performs multitasking of programs.

DOS does not run in protected mode, so does not allow any of these
features either, but an O/S such as OS/2, Unix or the to be released
Windows NT, which are true 32 bit operating systems, take full
advantage of the uP power.  Windows 3.1 is *not* an O/S...it still
needs DOS to do most of the work.

------------------------------

Date: Sat, 19 Dec 92 16:13:49 CST
From: Glauber <tellab5!wheaton!david.wheaton.edu!gmribeir@uunet.UU.NET>
Subject: screen savers

>        This is more of a hardware question. I use a program to
> customize the collor pallete of my VGA monitor, so that the colors look
> nicer.
> 
>        The problem is that the background color is not black. So when
> the screen blanker (e.g. burnout) blanks the screen, it does ot become
> black, but rather whatever color happens to be set in the pallete as 0.
> 
>        The question is: i suppose this makes the screen blanker
> useless (i.e.: it won't save the screen from burn out, will it?).


Sorry for the weird question. I hadn't inhaled anything fancy, was just
dead tired... Anyway, i found another screen saver that does the job,
and always cleans it to black. And it was written by Mark Adler, which
means it's good. In Simtel:

Directory PD1:<MSDOS.EGA>
 Filename   Type Length   Date    Description
==============================================
ZAPSCRN.ARC   B   12288  890212  TSR blanks screen for EGA or VGA

						Glauber
Glauber Ribeiro
glauber@david.wheaton.edu
glauber%david.wheaton.edu@tellab5.tellabs.com

------------------------------

Date: Fri, 18 Dec 92 12:51:24 MET
From: Enrico <FISO1@vm.cnuce.cnr.it>
Subject: What HD to choose???

   I need some more disk space on my AT 386.  I asked some shops for
information on removable/rewritable disks.  The only that I found is
the RICOH-128MB; there is just a little problem, it's too highly priced
(3000000 I.L. it's about 2000$). Do nobody of you know if I can expect
this price will be broken down???  How much are that beasts priced in
your country???

    Merry Xmas & happy new year!!!!!
    Thanks in advance,       Enrico.

------------------------------

Date: 21 Dec 92 08:13:00 EST
From: "Jay Morris" <MORRIS@patrick-pims.af.mil>
Subject: IBM HelpLine Solved My Floppy Disk Problem!

>From: David Feustel <feustel@netcom.com>
>
>Ever since I started working with the 2.0 betas, I've been plagued by
>sector not found errors on my floppy disk. The problem turns out to be
>easily solved by popping the disk  (forcing a recalibrate) before doing
>a retry. Thanks to the anonymous IBM Helpline technician who figured
>this out.

This sounds a lot like the solution we had to a problem with early PS2
Model 30s.  When we first got them at a community collage where I'm
adjunct, a lot of them would stop recognizing the A: drive.  The
problem was it was not consistant.  We sent several back and weretold
that they was nothing wrong with them.  Finally, we got ahold of a
techie who gave us this procedure:
                                            
  1.  Insert fingers into drive.
  2.  Grasp drive.
  3.  Give gentle yank on drive.
  4.  Give drive sharp push.
  5.  Turn on PC and check drive.

Worked every time.  The real reason was that there were some problems
with the card edge conector losing contact and this would reseat it.

Jay E. Morris                         * Bad boys and girls don't get lumps  
morris@patrick-pims.af.mil            * of coal for Christmas. They get  
jmorris@tecnet1.jcte.jcs.mil          * underware!  (And so do very naughty
DSN: 467-7454                         * big girls, but that's another story.)
CIS:73007,3107                        *                                       

------------------------------

End of Info-IBMPC Digest V92 #206
*********************************
-------