[net.micro.pc] INFO-PC 8/8/82

glennw (08/20/82)

>From uucps Thu Aug 19 03:22:34 1982
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Date: Wed Aug 18 23:30:26 1982
To: philabs!cmcl2!floyd!harpo!eagle!mhuxt!mhuxa!mhuxh!glennw

From: INFO-PC <INFO-PC at USC-ISIB>
Subject: Info-PC Digest V1 #4
To: Info-PC: ;

Info-PC Digest          Sunday, 8 August 1982       Volume 1 : Issue 4

Today's Topics:

                              Amdek 300
                     PCFTP and VT52.BAS (2 msgs)
                           Tall Tree Review
                    Format of .EXE Files (2 msgs)

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Date:  6 Aug 1982 0900-PDT
From: Randy Cole <COLE at USC-ISIB>
Subject: Amdek 300
To: Info-PC

I bought my Amdek 300 12" green phosphor monitor for $137 plus tax
from Bison Products, Inc., P.O. Box 9078-184, Van Nuys, CA 91409.
Their store is at 16709 Roscoe Blvd., Sepulveda, CA 91343.  See the
August issue of BYTE, page 187, for their ad.

I also bought a AST combo (64K memory, expandable to 256K, plus
IBM-compatible RS-232 and printer ports) for $335 plus tax from Bison.
I am very pleased with it and the $335 seems to be about the lowest
price around for a combo card.  The same card is selling for $135 to
$220 more elsewhere.

Randy Cole
(Cole@ISIB)

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Date:     7 August 1982 1707-edt
From:     Brian N. Hess <Hess.Unicorn at MIT-MULTICS>
Subject:  PCFTP and VT52.BAS
To:       info-pc at ISIB

The VT52.BAS program can't be used to download files at 1200 baud.
This is not a fault of the author's; it's just that if you are running
the IBM RS232 interrupt handlers and then you turn the disk drive on,
some of the incoming characters are lost.  So if you want to download,
use 300 baud instead -- it works O.K.

Also, there seems to be something which it is not emulating correctly.
Of course, it's only Multics Emacs with it's timed-to-the microsecond,
optimized-to-the-character cursor and text movement sequences that shows
it up, but...  Will fix or report it when I track it down.  On to looking
at Multics Emacs CTL's...
                                        Brian

P.S. Of course,  ESC A, ESC B, ESC C, and ESC D don't work.

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Date:  8 Aug 1982 2016-PDT
From: Dick Gillmann <GILLMANN at USC-ECL>
Subject: Re: PCFTP and VT52.BAS
To: Hess.Unicorn at MIT-MULTICS, INFO-PC

I haven't noticed the download problem you mention.  I have downloaded
files using this program several times without trouble.  Is your
RS-232 card next to your diskette controller card?  Perhaps they are
interfering with each other.

I went out and bought the IBM Asynchronous Communication Support
package back in March when I got my PC.  What a burn!  The IBM
terminal emulator will only talk to TSO, CMS or other PCs.  And it's
just a glass TTY.  And it runs real slow.  I spent a day writing
VT52.BAS in Basic using the RS232INT machine language module that
comes with the IBM package.  As you might imagine, executing screen
commands in Basic is very slow.  Also, the RS232INT package does
obnoxious things like using a whole bunch of RS-232 lines it doesn't
really need, which requires you to buy an expensive cable or trick up
a cheap one.  So I gave up on it and wrote a real terminal emulator in
assembly language.

I've noticed that EMACS does bad things to PC terminal emulators, like
causing framing errors when it rewrites the mode line.  I'm completely
mystified as to how it can cause communication errors (assuming it
uses the normal TOPS-20 JSYSes).

/Dick

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

Date:  8 Aug 1982 1318-PDT
From: Billy <BRACKENRIDGE at USC-ISIB>
Subject: Tall Tree Review
To: INFO-PC

I wrote the following review for a local IBM-PC users group. Dick has
asked me to send it along to INFO-PC.


Tall Tree 512K Jram card & Quad Disk Modification

Tall Tree Systems makes a software package to modify PC-DOS to use
quad disk drives.  The terminology here is a little strange. First,
all current disks are double density. I guess single density disks
must have gone out of style long before I became interested in
personal computers. The standard drives supported by IBM are all
manufactured by Tandon and have 40 tracks per side. With 4K bytes of
usable information per track, each diskette surface holds a total of
160K bytes.  Double sided disks can hold a total of 320K bytes.
Tandon also makes drives which can write 80 tracks per side. One of
these drives will store 640K bytes and is called a quad drive as it
holds four times the information of the standard IBM drive. These
drives plug right into the PC and look identical to the standard
drives. The following table illustrates the various disks one can use
on an IBM PC.  Drive #Sides Tracks/side Total capacity Remarks

TM100-1   1       40            160K       Standard DOS 1.0 drive
TM100-2   2       40            320K       Supported by DOS 1.1
TM100-3   1       80            320K
TM100-4   2       80            640K       Supported by Tall Tree


My system consists of a Tandon TM100-2 as my "A" drive and a Tandon
TM100-4 as my "B" drive. I paid $306 and $405 plus tax for the two
drives from Priority 1 in Chatsworth. I have since seen cheaper
prices.

If I run standard DOS 1.1 on my system, it will behave as though I
have two 320K byte drives. DOS will use all the available space on the
"A" drive and the first 40 tracks on both sides of my "B" drive.  The
diskettes are NOT interchangeable, but I used such a system for a few
weeks while waiting for the Tall Tree software to arrive.

Tall Tree supplies two programs, JFORMAT and JEL. JFORMAT replaces the
FORMAT program in DOS.  JEL is a program to reconfigure the system.
For example JEL will allow the user to mount a single sided 40 track
diskette (as written on a TM100-1) on a quad drive (TM100-4). One can
then read and write that disk just as if it was the standard IBM 160K
drive.

How does this all work? I don't know, but I suspect the program
simulates a 40 track drive on an 80 track drive by writing a track
then skipping a track etc... This is a somewhat dangerous proposition.
Tall Tree guarantees that you will be able to read and write 40 track
disks, but they warn that not all 40 track drives may be able read
disks written by 80 track drives as the tracks are narrower and the
drive will be more sensitive to errors in alignment.

There may be yet another problem with protected programs. I don't know
how these disks will perform with stand alone bootable systems that
read the disk without the help of DOS. Frankly I couldn't care less
about this issue.  I have no intention of purchasing any software that
can't be copied to a Winchester disk. The current crop of copy
protected products will not run on a Winchester system. This shouldn't
be too much of a problem if you keep one of the standard IBM supported
drives as your "A" drive.

I have also purchased Tall Tree's JRAM card which contains 512K of
RAM. This memory can be used as main memory available to DOS or made
to look like an extra disk drive. I typically give DOS an extra 128K
of memory (for a total of 192K) and use the rest to simulate a third
or "C" disk drive.

The first question that comes to mind is: Is 512K really twice as good
as 256K.  For me the answer has definitely been Yes. I do most of my
work using the macro assembler which is a terrible memory hog and slow
enough without waiting around for floppy disks. I usually use my "C"
disk as the system disk.  With the macro assembler, linker, editor,
and working copies of my programs and listings, the disk fills up
pretty quickly. I have ordered FORTRAN and my memory needs are
growing. The two passes of FORTRAN and library alone take up more than
256K.  Pascal takes up 336K.

It is in this area of expandability that the Jram board really shines.
Up to four JRAM boards can be used on a single system, resulting in 2M
bytes of memory.  Each 512K byte board uses one system slot. You might
ask how this is possible when the 8088 only supports 20 bits of
addressing and and not all of that can be devoted to real user memory.
The Jram board has special hardware to allow it to change its apparent
address on the bus. The mechanism is quite simple but beyond the scope
of this review. In short it allows the use of gobs and gobs of memory.
Right now more memory is beyond my pocketbook's reach but memory chips
are only getting cheaper, and I look forward to the day when I can
afford to have a few megabytes sitting on my desk.

I have not done any extensive benchmarks, but I have made one informal
test.  I use a batch file to assemble and link a program I am
developing. If I run this application using a combination of my two
disk drives it takes 3 minutes 24 seconds. If I run the same file
using the electronic disk it takes just under two minutes. I expect
this gap will widen as my programs grow in size.

I can not recommend the JRAM board to users who tend to use packaged
programs and BASIC for program development.  Neither of these
applications do extensive disk I/O or require huge amounts of memory.
The board is pretty expensive and these users would probably be better
off getting one of the multi-function boards that includes a calendar
clock and I/O ports.  If one is doing program development with the
macro assembler, FORTRAN, Pascal, or perhaps the new BASIC compiler,
the JRAM board will save a lot of wear and tear on your disks and your
nerves.

The JRAM board retails for $1200 or $2000 for two boards. The JFORMAT
JEL diskette with DOS modifications to support the electronic disk and
quad drives sells for $50. A diskette is included when you buy the
JRAM card.

Tall Tree Systems
1036 Los Altos Avenue
Los Altos, CA 94022
(415)941-8748

Since I wrote this review there have been several new developments:
First Tall Tree has released a print spooler as part of their software
package.  I don't have a printer so I can't give any first hand
information on how the spooler performs.

I am told they are also working on an operating system modification to
write 9 sectors per diskette track rather than IBM's standard 8
sectors. John Henderson of Tall Tree informs me that this modification
will be transparent to the operating system, and that the drives will
auto sense which type of diskette is currently mounted. This
modification will provide an extra 512 bytes per track or 20K bytes
per side on a 40 track drive or 40K bytes per side on an 80 track
drive. This will bring the total capacity of a TM100-4 up to 720K
bytes.

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

Date: 8 Aug 1982 1451-PDT
Subject: Format of .EXE files...
From:  William "Chops" Westfield <BillW@SRI-KL>
To: Info-PC at ISIB

Can someone explain the format of MSDOS .EXE files ?  I want
to have a program that is both BLOADable from basic, and
executeable from DOS. (or, is there a quicker way of reading
a .COM file (other than input$, poke. (which fails if there
is a ^Z in the file someplace, BTW.))

Thanks
Bill W

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

Date:  8 Aug 1982 2024-PDT
From: Dick Gillmann
Subject: Re: format of .EXE files...
Sender: INFO-PC at USC-ISIB
To: BillW at SRI-KL, info-pc

The format of .EXE files is explained in Appendix F of the DOS 1.1 manual.
It's not in the DOS 1.0 manual.

Can someone explain the format of .OBJ files?  I'd like to write a
compiler that doesn't require running the assembler, too.

/Dick

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End of Info-PC Digest
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