🚀 go-pugleaf

Info-IBMPC Digest     Wednesday, June 11, 1986     Volume 5 : Issue 60

This Week's Editor: Richard Gillmann

Today's Topics:

                   640K on XT Motherboard (2 msgs)
                         DOS 3.1/3.2 (3 msgs)
                      Keyboard Extension Cables
                      How to Make a Null Printer
                        8 Serial Ports for AT
                           Update of GRAPH
                     Inline Code for Turbo Pascal
                               INT 20H
                     Computer/computer disk read
                            Fate of Davong
                 Software Source Code Control Systems
                      PC/IX - Hercules Mischief
                         STB Graphics Boards
                       The Big SQueeze (3 msgs)

Today's Queries:

                5.25" Drives for Toshiba T-1100 Wanted
                      Hardcard from Plus (Query)
                        Loading Modules Query
                      Epsilon and Windows Query
                  DisplayWrite3 under DOS 3.1 Query
                  Low-level Hard Disk Programs Query
                        IBM PC Networks Query
           Serial interface specs needed for NEC Spinwriter
                       Dataflow Diagrams Query
                       Apple Imagewriter Query
                            AutoDex Query
                Info wanted on Undocumented DOS Calls
                        Jlaser Software Query

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

Date: Mon, 9 Jun 86 11:48:54 edt
Subject: IBM-XT Motherboard Upgrade to 640K
From: Billy <BRACKENRIDGE@USC-ISIB.ARPA>

I got two responses on the 640K motherboard update:

From: Tony Brand <BRAND@SUMEX-AIM.ARPA>

I installed the 640K motherboard upgrade in my PC portable (i.e.luggable),
which has the same motherboard as an XT. It works very well. The XT
motherboard DIP switches should be set for maximum memory (256k for an
unmodified board) if 640K is installed. I highly recommend this mod
it's easy to install even if it does void the warranty.

Tony Brand
Trenton State College, NJ

From: Steve Ligett <stevel%dartmouth.edu@CSNET-RELAY.ARPA>

When upgading an XT motherboard to 640k, the switches should
be set to indicate "256k installed".  The switches really
indicate how many banks of memory are installed.  (You can also
do a 64k downgrade - four banks of 16k chips - and leave the
switches set for "256k".)
Steve

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

To:  INFO-IBMPC@USC-ISIB.ARPA
From:       "Roger Fajman"  <RAF%NIHCU.BITNET@WISCVM.WISC.EDU>
Date:     Tue, 10 Jun 86  21:13:22 EDT
Subject:  640K on XT Motherboard

The following describes an easier way to upgrade an XT
motherboard to 640K.  I've done it and it works fine.
Just be sure to get all the chips in their sockets
properly.  On an IBM Portable PC, getting at the chips
requires removal of the disk drives and motherboard, a
fairly lengthy process.

Roger Fajman

BITS and PCs
by Jerry Schneider

Copyright (c) 1986, Capital PC User Group Inc.
This material may be republished only for internal use
by other not-for-profit user groups.

Published in the March 1986 issue of the Capital PC Monitor.

640K Memory on Your XT/Portable System Board

The "User to User" column in the September 1985 Monitor included
an article that described how to upgrade an IBM PC-XT or Portable
to contain 640K memory on the system board.  While that
procedure is very effective, it requires that the user solder a
jumper wire between two points on trom the Buying Group for around
$22 (for each bank of nine chips).

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

To: kegel@juliet.caltech.edu
Cc: info-ibmpc@usc-isib
Subject: Re: DOS 3.1 Editing Keys
Date: Wed, 11 Jun 86 14:36:14 -0500
From: Mark Colan <mtc@ATHENA.MIT.EDU>

WAB's comment is wrong.  My (unhacked) DOS 3.10 system DOES allow
the use of ^U and ^W.  I can't imagine it not working on all AT's;
it has worked on ALL AT's I've used (and that's many).

BTW, these seem to have been removed from DOS 3.20!

Mark Colan
MIT Project Athena

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

Date: Wed 11 Jun 86 07:46:31-EDT
From: Bruce Hillyer <BRUCE@CS.COLUMBIA.EDU>
Subject: Patch DOS 3.1 for Ctl-U, Ctl-W
ReSent-From: Billy <BRACKENRIDGE@USC-ISIB.ARPA>

I had sent this patch directly to you some time in the past, but it never
made it into INFO-IBMPC.  Old versions of pc-dos 3.1 had the control-u and
control-w code patched out with nop's; newer versions don't.

Here's the patch again; I'm also sending a copy directly to the guy who asked.

Here is a patch to make dos 3.1 recognize control-u as line delete, and
control-w as word delete (like Tops-20).  This patch is for the hidden
file ibmdos.com  length 27760, date 7-Mar-85  13:43.

Using a copy of your dos diskette, do the following.

1.  Unprotect the hidden file ibmdos.com .  For example, with the
    Norton utility FH, set not-system, not-hidden, not-read-only.
    The CHMOD program in the info-ibmpc library may also work.

2.  Use debug as follows:

A>debug ibmdos.com

-u 1db9
...this should show code like:
        cmp al,17
	nop
	nop
	cmp al,15
	nop
	nop

...and the following patch will change it to
	cmp al,17
	jz 1e1b
	cmp al,15
	jz 1e12

-e 1dbb 74 5e
-e 1dbf 74 51
-w
-q

3.  Reprotect ibmdos.com, and boot the system from this dos.  After you
    are convinced it works, you may wish to use the  sys  command to move
    the patched system to the hard disk.

[Sorry about not including this in INFO-IBMPC the first time, but my
 DOS 3.1 already had this patch directly from Microsoft. It later appears
 that some DOS 3.1s have this patch and some don't. -wab]

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

To: info-ibmpc@usc-isib.arpa
Subject: New IBM Keyboard (AT 339) and DOS 3.20
Date: Wed, 11 Jun 86 15:23:17 -0500
From: Mark Colan <mtc@ATHENA.MIT.EDU>

I recently purchased a PC/AT model 339, ie the 8Mhz 30Mb disk version
with the NEW keyboard.  There has been some controversy over the new
keyboard, both from a layout standpoint and from a compatibility standpoint.

PC Tech Journal, June 1986, p12 has a good summary on the layout issues.
I will underscore the article's points with those that I am the most concerned
with:

* I hate the location of the CTRL key, and the CAPS-LOCK key.  I'm
  constantly hitting CAPS-LOCK when I really meant CTRL.  This is partially
  because I use a uVaxII and the keyboard is (almost) in the "right" place.
  I wish that the CAPS-LOCK key would simply go away! I NEVER want to be
  in upper-case mode, and am frequently annoyed by falling into it.  I'm
  considering prying off the keycap!

* I don't like the new location of the function keys, even tho now they
  are in the "right" place.  In particular, chording (like when you want
  to press Alt-F1) now requires two hands (for most people), and I discover
  how much I relied on the position of the keys to find them, as in dealing
  with programs which use the Function Keys for menu control.

In order to use the new keyboard, you should probably use DOS 3.20.
If you use DOS 3.10, the new cursor keys and the new Home, PgUp, etc keys
generate an "alpha" character (ie, the Greek letter) on the screen, rather
than having the desired effect.  You CAN use the numeric keypad to do
the cursor moving etc, but the 339 BIOS, upon powering up, apparently
SETS the numeric lock by default, so you have to unset it each time you
boot.

I use DOS 3.10 anyway, though, because in DOS 3.20 the ^U and ^W keys no 
longer have the function they did in 3.10, and I can't live without
the ^U in particular.  (It really blows my mind that the ESC key,
the only men compression ratios hover around 33% {compressed file
is 66% of original, whereby 'text' is typically compressed a little
better, and 'executables' less}.  Typical LZW compression ratios
average 55% - highest compression is achieved with pixel-information
{values of 90% are typical} - followed by 'text' with 50% and
executables around 20%.  Although the original 'paper' on LZW
suggested implementation between CPU and peripheral devices
[terminal,disk-drives,mag-tapes] - current usage encompasses
file-compression {Unix COMPRESS, MSDOS ARC, CPM UNArc} - highspeed
proprietary MODEM-protocols {"LZW in SILICON"} and 'picture
transmission' at 1200 baud.

Rgds,
Bernie

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

Date: Sun, 8 Jun 1986  22:45 MDT
From: Keith Petersen <W8SDZ@SIMTEL20.ARPA>
To:   Julius Smith <JOS%CCRMA@SU-AI.ARPA>
Cc:   INFO-HZ100@RADC-TOPS20.ARPA, INFO-IBMPC@USC-ISIB.ARPA
Subject: SQueezed, LBR, and ARC files

Some of the files in the SIMTEL20 MS/PCDOS software libraries have
been transformed by using one or another of the standard public domain
utilities that either SQueezes, LiBRaries, or ARChives files.  This is
done to compress the files to minimize download time, and/or combine
several related files into a single easily-managed file.

These processed files are specially named with a filetype (the last 3
letters of a filename after the '.') that signifies the
transformation. These are:

              .ARC   for files archived with ARC.EXE,
              .LBR   for files libraried with LU.EXE, and
              .?Q?   for squeezed files (middle letter is a Q).

USQ.COM is used to unsqueeze, or expand files that have a "Q" as the
middle letter of the filetype.  Such files have been squeezed, or
compressed with SQ.COM or something similar.  These programs use
Huffman Encoding to reduce the size of the target file.  Depending on
the distribution of data in a file it can be reduced in size by 5% to
60% by squeezing it.  If you download a file with a filetype
indicating that it is squeezed, you will need USQ.COM to expand it
before you can use it.

ARC is used to create and maintain file archives.  An archive is a
group of files collected together into one file in such a way that the
individual files may be recovered intact.  ARC will automatically
compress member files when adding them to the archive, and will expand
them upon extraction.  For files with the .ARC extension, you must
have a copy of ARC.EXE to extract the component files.

LU and its relatives (LUP, LUU, LUE, LUT, LU86, LAR etc.), maintain
libraries of files.  Most LU-type programs do not perform any
compression.  Because of this, most people will squeeze files before
adding them to a library if they want to save space.  If you want to
remove the component files from an .LBR file, you should have a copy
of LUE.COM.  This will break up the library into its component parts,
and optionally unsqueeze any .?Q? files at the same time.  LUU.COM
will create a .LBR file.

For information on ARChives, see the documentation for ARC.  The
various LU utilities will explain .LBR's and LUDEF5.DOC explains the
layout of these files in detail.

For SQ(ueeze) and USQ (unsqueeze) see SQUEEZE.TXT which provides a
background on squeezed files.

A complete list of the MSDOS files and CRCs is available via ftp as
PD:<MSDOS>MSDOS.CRCLST.  A shorter version with just filenames is
PD:<MSDOS>FILES.DIR.  Both are updated frequently.

--Keith

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

Date: Mon, 9 Jun 86 16:57:17 PDT
From: WU%FAR@ames-io.ARPA
Subject: VMS SQueezed files to PC
To: info-ibmpc-request@isib

In reply to the use of SQ under VMS, use SET FILE TYPE FIXED to 
transfer the file to a PC.  Otherwise you lose the two byte record header
of a FILES-11 file.

Alex.

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

Date: Sat, 7 Jun 86 23:43 UT
From: OGASAWARAT%HAW.SDSCNET@LLL-MFE.ARPA
Subject: 5.25" Drives for Toshiba T-1100 Wanted

Does anyone know if there is an alternate source for 5.25" external disk
drives for the Toshiba T-1100 portable?  The $400 price tag for the one