Z*Magazine: 8-Mar-92 #205
From: Atari SIG (xx004@cleveland.Freenet.Edu)
Date: 10/09/93-04:29:52 PM Z
From: xx004@cleveland.Freenet.Edu (Atari SIG)
Subject: Z*Magazine: 8-Mar-92 #205
Date: Sat Oct 9 16:29:52 1993
| (((((((( | Z*Magazine International Atari 8-Bit Magazine
| (( | ---------------------------------------------
| (( | March 8, 1992 Issue #205
| (( | ---------------------------------------------
| (((((((( | Copyright (c)1992, Rovac Industries, Inc.
| | Post Office Box 59, Middlesex, NJ 08846
| (( |
| (((((( | CONTENTS
| (( |
| | * The Editors Desk..........................Ron Kovacs
| ((( ((( | * Z*Net Newswire......................................
| (((( (((( | * Atari Forums Celebrate 10th Anniversary...Mike Naver
| (( (( (( (( | * 8-Bit Write-in Campaign..............Jeff McWilliams
| (( (( (( | * 1050 Into An Indus.........................Rick Mier
| (( (( | * Light Sensor For The 8-Bit...............Kevin Jones
| | * Line Noise..........................................
| (( | * Z*Mag Archives - 1987...............................
| (( (( | * The History Of Atari................................
| (((((((( | * Adventures In Structured Programming......Mike Stomp
| (( (( |
| (( (( | Publisher/Editor..........................Ron Kovacs
| | Contributing Editor........................John Nagy
| (((((((((( | Contributing Editor......................Stan Lowell
| (( | Contributing Editor........................Bob Smith
| (( ((((( | Newswire Staff......................................
| (( (( | Z*Net New Zealand.........................Jon Clarke
| (((((((((( | Z*Net Canada.........................Terry Schreiber
| |
|-------------| $ GEnie Address..................................Z-NET
| ONLINE | $ CompuServe Address........................75300,1642
| AREAS | $ Delphi Address..................................ZNET
| | $ Internet/Usenet Address................status.gen.nz
|-------------| $ America Online Address......................ZNET1991
| |
| Z*NET | * Z*Net:USA New Jersey...(FNET 593).....(908) 968-8148
| SUPPORT | * Z*Net:Golden Gate......(FNET 706).....(510) 373-6792
| SYSTEMS | * Blank Page.........(8-Bit FNET 9002)..(908) 805-3967
=======================================================================
* THE EDITORS DESK by Ron Kovacs
A special word this week to Stan Lowell who is currently being
hospitalized. The entire staff wished Stan a speedy recovery. If you
would like to pass along some words of encouragement, send a card to
the following address:
Z*Magazine
Post Office Box 59
Middlesex, New Jersey 08846-0059
Attention: Stan Lowell
======================================================================
* Z*NET NEWSWIRE
======================================================================
HAUG AT IEEE COMPUTER FAIR
The Huntsville Atari Users Group participated with Ralph Rodriquez of
Atari Corporation in the IEEE Computer Fair. Rodriquez showed off
Atari UNIX at the event. Dealers in Huntsville, Robbins and AB Stevens
showed Atari solutions to music with HAUG. The booth was showing one
of the largest presentations of Atari applications. 20,000 people are
reported to have attended.
ATARI TO ATTEND HAWAIIAN SHOW
Atari Corps Mike Groh will be in attendance at the Hawaiian User Group
Show. Also in attendance will be Impact Marketing.
CENTER FOLD AD BY ATARI APPEARS
LA Computing Magazine, with 1,500,000 subscribers contains a center
dual page full color advertisement by Atari Corporation. The ad offers
a Desktop Publishing bundle for $2999.00 which contains the following:
MegaST2 with 50 Meg hard disk, SM147 Monitor, SLM605 Laser Printer,
Migraph Hand Scanner, and choice of PageStream or Calamus. Along with
the full screen shots of Atari software, there is a full listing of
dealers from across the country participating in this special offer,
they are:
B&C Computer Vision California 408-986-9960
Butler Computer Washington 206-941-9096
Caves Creek Computer Washington 206-783-0933
CompuSeller West Illinois 708-513-5220
Computer Center of Davie Florida 305-583-6028
Computers Etc. Connecticut 203-336-3100
Computer Rock California 415-751-8573
Computer Studio North Carolina 704-251-0201
Digital Imagining Systems Florida 305-756-0446
Computer Warehouse California 916-971-9812
IB Computers Oklahoma 503-485-1424
IB Computers Oklahoma 503-297-8425
Jenkins Computer Texas 800-880-6938
Manny's Computer New York City 212-819-0576
Mid-Cities Comp/Soft South Carolina 803-788-5165
Music Arts Florida 305-581-2203
Run PC Colorado 303-493-5565
San Jose Computer California 408-995-5080
Team Computers Michigan 313-445-2983
Toad Computers Maryland 410-544-6943
Winner Circle Systems California 510-845-4814
NEW FAX MODEM PROGRAM
Joppa Software Development's "STraight FAX!", will work with Class 2
compliant send/receive FAX modems and SendFAX modems (in send only
mode). The first showing will take place at the upcoming Toronto TAF
show April 4-5. Also, a GEnie online conference is scheduled on
Wednesday, March 25, 1992.
ICD LAUNCHES ROUNDTABLE ON GENIE
ICD is now taking another step forward in providing technical support
to its many customers by opening a product support RoundTable on GEnie.
The ICD RoundTable will be hosted by Douglas N. Wheeler. Several other
ICD employees will also frequent the RoundTable sharing their own
expertise. The ICD RoundTable can be found at page 1220 or accessed
with the keyword ICD from any GEnie page prompt.
MICHELANGELO MAKES UNWELCOME DEBUT
The long-awaited Michelangelo virus struck around the world Friday,
though it did not appear to be the data disaster that some had
predicted. State Department official reported Friday that the virus
had struck IBM-compatible computers at three U.S. missions: Toronto,
Canada, Addis Ababa, Ethiopia, and La Paz, Bolivia. The problem was
fixed before any damage could be done. The State Department's
computers in Washington were not affected by the virus. New York state
authorities reported at least three machines infected with the virus,
but all were caught before they could go off. Egghead Software said
that sales of anti-virus software were running 3,000 percent ahead of
last week. The virus caused damage in at least eight computers in
Japan in the early hours of March 6, and China's Ministry of Public
Security said it had found "fewer than 10" infections during a survey
of computer centers nationwide. In Poland, considered a haven for
computer software pirates, computer owners lined up at software stores
to buy anti-virus software Thursday. NASA had 200 infected computers,
and the destructive virus had also been found in computers installed in
Senate offices. See related story elsewhere in this week's edition.
SPA REACHES SETTLEMENT
The Software Publishers Association announced that a settlement has
been reached in a software copyright infringement suit filed against
Cato Corp., by Lotus, Microsoft, Symantec, and WordPerfect. The
lawsuit was filed on Wednesday Sept. 25, 1991, and Cato Corp.
cooperated fully with the plaintiffs in providing an inventory of all
of the commercial software then in use on all of its personal
computers. Cato Corp. has agreed to a monetary settlement in the
amount of $50,000. Cato has also agreed to the entry of a permanent
injunction that will prohibit further copying and require them to
obtain software only from authorized suppliers. The Software
Publishers Association also has distributed free of charge self-audit
materials designed to help businesses, government entities, and
educational institutions manage their internal software practices. To
obtain a copy of the SPA Self-Audit Kit and SPAudit, a software
inventory management program, companies should write to: SPAudit,
Software Publishers Association, 1730 M Street, NW, Suite 700,
Washington, D.C. 20036.
======================================================================
* ATARI FORUMS CELEBRATE A TENTH ANNIVERSARY by Michael Naver
======================================================================
Reprinted with permission from CompuServe Magazine. This article may
not be reprinted without the written permission of the author and
CompuServe Incorporated. Copyright (c)1992.
As veteran Atari forum members tell the story, it was a classic example
of the generosity and closeness of the Atari forum community on
CompuServe: one member, immobilized in a body cast for three months,
keeping in touch with the outside world through messages from his
colleagues on the Atari ST forum.
It was perhaps the most dramatic but otherwise characteristic example
of the loyalty that Atari forum members express as they mark the tenth
anniversary of Atari forums on CompuServe (GO ATARINET).
Looking back on it now, the auto accident victim, Dave Groves, then an
assistant "sysop," said that his online companions "meant more to me
than I can express. The time and closeness spent with the staff and
our members made the forums a wealth of information and a home away
from home for me."
During his recuperation, Groves' forum colleagues "stood by me through
thick and thin. They were my sole contact with reality and provided me
a very warm and positive family to replace the one I never had outside
of CompuServe."
This sense of family has characterized the Atari forums from the
beginning, in the fall of 1981, when the original (and current)
administrator, Ron Luks, along with two other pioneers, started the
Atari 8-bit forum.
"Atari computer users have been the underdogs of the computing world
from day one," Luks explained. "The popularity of the online forums
was a result. We were the only place people could go to get support
for our machines. You tend to develop an intense loyalty to the
machines and to each other."
The family spirit is matched by a strong independent streak. "We
support the products, and at times have not been very popular with the
company," says Luks. "Our current relations with the company, however,
are the best in years."
Luks remembers his own introduction to Atari. "I was a stock and
options trader in a Wall Street brokerage firm back in 1981," he said.
"I was walking past a computer store in Manhattan planning to buy an
IBM PC. I saw the Atari 800 running a game called Star Raiders."
"I was so mesmerized by the game that I walked in off the street and
took the computer home, figuring I would play with it until I got a
serious machine. But that old 8-bit did everything I needed, so I
never bought the IBM." With his modem and CompuServe introductory
pack, Luks soon was telecommunicating in an Atari section of the
Popular Electronics Forum. A few months later the first Atari forum
opened on CompuServe, called informally "Sig*Atari."
A second pioneer, Michael Reichmann, of Toronto, remembers that
CompuServe was sponsoring a promotion in Toronto. "I said, 'Hey,
online information, that sounds neat.' I bought a 300-baud modem and
got hooked," Reichmann said. "There was something very clubby about
the Atari community in the early '80s, something unique," he recalled.
"If you had an Atari, you knew you had a great machine, but the rest of
the world didn't. It was a small, tightly knit group of a few hundred
people, and 80 per cent us hung around Sig*Atari to exchange ideas and
information."
At the time Reichmann was a vice president of the Canadian Press news
agency. "My background was in photography, so graphics were important.
Back in '81 the Atari 800 was the whiz-bang graphics computer. What
was terrific about CompuServe was being able to get in touch with Atari
software developers all around the United States and Canada.
The third founder, Steve Ahlstrom, of Littleton, Colo., recalls that
"all of us were discovering not only the computer but also the power of
telecommunications. We came from vastly different walks of life, but
we became close because of our common interest."
Ahlstrom served as an assistant Atari sysop for five years, where he,
too, found business opportunities writing Atari software. Later he
became administrator of the Amiga forums, where he can be found today.
Ahlstrom was not the only Atari forum pioneer to branch out to other
CompuServe forums. Groves' dramatic story is another example.
A resident of Miami, Fla., Groves was driving home from his job as a
bank vice president when he fell unconscious at the wheel, the result
of faulty diabetes medication. He hit another car on the expressway at
65 miles an hour. After his 3 months in a body cast, he spent 9 months
in therapy.
So profound was the experience that Groves three years ago established
the Diabetes and Hypoglycemia Forum on CompuServe (GO DIABETES) to
share the kind of information that could prevent accidents like his.
For Groves the Atari ST is still his computer of choice. "I use it for
heavy duty business applications, which surprises some people. It is a
serious business machine."
Newer forum members, people who were not present at the creation of the
8-bit or ST forums but who have become loyal Atari ST users, cite the
same community spirit as a plus. Bill and Pattie Rayl, of Ann Arbor,
Mich., met in college and got an Atari ST as a wedding gift three years
later. The following year, 1987, they joined CompuServe.
"Our CompuServe experience has meant making a lot friends and business
contacts," Pattie said. The couple produces a nationally distributed
magazine for Atari users called Atari Interface. Also, they're the
unofficial sponsors of twice-weekly online conferences -- Thursday
evenings for Atari 8-bit users and Sunday evening for ST users. "The
sysops have been great to us," Pattie said. "They take a hands-off
approach, and let the users do their thing. I really like that."
Another enthusiast is Jim Ness, a West Chicago, Ill., motor equipment
salesman. In 1986 he bought an Atari 520 ST, which he described as a
"basic but very competent machine with a color monitor and disk drive
that sold at K-Mart for about $500." Ness began spending time in the
Atari ST forum. "I knew that if you could find a group of people who
used the machine, you could find software, plus advice on how to use
your computer." That's how things turned out. Ness became a "hobbyist
programmer" and wrote an automated access program for the Atari, called
QuickCIS. "Most people who regularly visit Atari forums use it," he
said. Ness finds the forum managers "very good, very friendly, very
helpful. If that weren't true, I wouldn't have been a member for five
years."
Assisting Luks as forum sysops are Mike Schoenbach, assistant manager;
Dan Rhea, Bill Aycock, Keith Joins, Bob Retelle, David Ramsden and John
Davis, ST sysops; Don LeBow and Bob Puff, 8-bit sysops; and Marty
Mankins, Judy Hamner and B.J. Gleason, Portfolio sysops.
What's ahead for Atari? No one knows for sure, but Luks noted that
since the days when Atari was on the cutting edge as a low-cost, high-
powered graphics computer, there was a dearth of new products for
several years. Now, significant products are being released. As they
are available, Atari's loyal band on CompuServe will be ready.
Michael Naver is a contributing editor of CompuServe Magazine.
=======================================================================
* 8-BIT WRITE-IN CAMPAIGN by Jeff McWilliams
=======================================================================
Heads Up, Atari 8-Bitters!! This Is For YOU!
Beginning 1992, the Atari 8-bit computers- and the community of USERS
who still cherish these machines- have been officially discarded by
Atari Corporation.
BUT WE REFUSE TO ROLL OVER AND DIE AT ATARI'S COMMAND!!
We believe there are enough of us left to pursue our 8-bit interests
independently of Atari Corporation.
Would you like to see a common forum in which users, developers, and
vendors can communicate? A print medium wherein advertisers can be
assured of reaching their intended audience, and where users can look
with confidence for information about new products? A user-oriented
publication to fill the void left by the collapse of ANTIC and ANALOG?
My name is Jeff McWilliams, and I'm a dedicated 8-bit user. I want to
present the Atari 8-bit community the chance to gather under one
publication dedicated exclusively to the Atari 8-bit computers. A
magazine that will unite our community and give it the strength it needs
to survive. A forum where users can ask tough questions and read
unvarnished product reviews. A magazine whose ads will be almost
exclusively from 8-bit vendors.
I propose a write-in campaign to Atari Interface Magazine, asking for a
separate, exclusively 8-bit magazine called "Atari Classics". Atari
Interface Magazine already has a strong presence in the Atari community.
For several years AIM has been a combined ST/8-bit magazine whose
publishers have indicated a willingness to support the Atari 8-bit
community as long as interest warrants it. NOW is the time to ask them
for our own magazine!
As Campaign Manager, I will act as the focus for this effort. Now, you
might be wondering, "WHAT CAN I DO TO HELP?". That part is EASY!
Just SEND me your NAME and POSTAL MAILING ADDRESS. I will mail you a
FREE Information Kit describing our goals in greater detail. Included
with the Kit is a stamped postcard on which you can express your
interests and willingness to subscribe to an exclusively 8-bit magazine.
(Or, if you disagree with our approach, you can just toss it away and
that will be the end of it- BUT WE DON'T THINK YOU WILL!) You'll also
be invited to indicate your willingness to PARTICIPATE in the magazine
DIRECTLY by being a regular columnist, editor, or just writing about a
special project you did or review a product you used.
Ben Poehland, the former 8-bit Editor of Current Notes Magazine, is
fully supporting this campaign and has offered to donate his services to
"Atari Classics" when repairs to his fire-damaged home are completed
later this year.
The cutoff date for receiving the postcard responses is: MARCH 31, 1992.
If by that time I have received 500 positive commitments via postcard,
they will all be sent to AIM along with a petition requesting the
formation of our proposed exclusive 8-bit publication "Atari Classics".
If I receive less than 500 replies, then we will know that the 8-bit
community has indeed become a lost and hopeless society.
TIME IS RUNNING OUT. THIS MAY BE THE LAST OPPORTUNITY YOU WILL HAVE TO
KEEP YOUR MACHINE ALIVE AND SHARE EXPERIENCES WITH FELLOW USERS.
IMPORTANT!! Only the OFFICIAL Campaign postcards will be accepted!
Those responding by other means will be mailed an Information Kit with
which they can register their official response. Regrettably, due to
limitations of time and cost, the Campaign will be restricted to
addresses in the USA only. However, unofficial responses from outside
the USA are welcome and will be included in the final count.
PLEASE DO NOT SEND MONEY! If anyone wishes to assist the Campaign, they
can do so by posting this release in its unmodified entirety to other
on-line services, BBS's, user groups, friends, and vendors. Additional
assistance can be rendered by gathering names and addresses of Atari 8-
bit owners and furnishing them to me so I can mail them an Information
Kit.
If you're REALLY SERIOUS about keeping your Atari 8-bit classic computer
alive, be sure to obtain the Information Kit and return the included
postcard appropriately filled in. Every day more 8-bits get stashed in
attics or closets, or simply thrown away. Atari's Classic 8-bit
computers- the 800/XL/XE machines- are every bit as useful and
productive today as they were in the heyday of 8-bit technology. They
deserve a better fate than the local landfill!
CONTACT ME:
Jeff McWilliams
2001 G Woodmar Drive
Houghton, MI 49931-1017
GEnie: J.MCWILLIAM3
INTERNET: jjmcwill@mtus5.mtu.edu
=======================================================================
* 1050 DRIVE TRANSPORT INTO AN INDUS GT by Rich Mier
=======================================================================
My Indus Disk Drive has a lot of miles on it and, alas, was coming up
with some Strange Errors. After swapping all the socketed chips on the
main board, I determined that it must have a bad Read/Write head.
By now I had been using it with the case removed, the Deck resting on
the top of the front panel and a wooden pencil across the rear beneath
the deck. The TANDON Part No. is 211014-001 and checking around town, I
could find no replacement deck, anywhere. Everyone I talked to said I'd
have to send it back to Future Systems, or at least go to them for a new
deck.
I can't afford to lose my disk. I only have one as I have a 320K XE and
a 256K MIO. All I need is one when I have 2-192K RAMDISKS available.
American Techna-Vision advertises a direct replacement Mechanism for a
1050 Drive so I called them to see if it would work in the Indus. They
didn't know and couldn't even give me a Tandon Part Number. They did
say that they have gotten orders from small companies that repair Indus
drives. Taking a chance, I ordered one on the condition that I could
return it if it wouldn't work. $47.50 plus shipping and UPS 2nd day
Air. Total, $56.00. Cheaper than what it was going to cost me if I had
to take it to a Dealer or send it out to be fixed.
Monday evening I ordered it and Thursday afternoon it showed up. I
checked the Part Number first. Different! Part No. 216024-019.
Digging out the wires, I found a couple markings that were the same.
Mechanically, it was the same, but on closer examination there were
several differences.
1) There was no Timing hole sensors.
2) The plug coming from the Stepper motor had 6 wires versus 5 on the
old deck (both have a 6 wire connector). Also, the colors were
completely different.
3) The wires coming from the drive motor where the same color, but
about 3 inches shorter. (The Drive motors where identical.)
4) The micro switch against the rod used to twist and engage the floppy
had 3 wires on it and the old one, 2.
5) There was 1 less connector plugs.
Cutting some plastic tie-wraps on both decks, I traced out the wires.
Here's what I found:
The missing connector is J12 (4 pins) on the old deck. It is the timing
hole sensor. Well, Atari doesn't use the timing hole. Ignoring it, I
went on.
The three wire connector marked '14' on the new drive is the Micro
switch marked '5' on the old one and isn't used.
The two wire connector marked 'J12' on the new drive is also 'J12' on
the new one. It is the front LED and isn't used on the Indus.
'J11' on both decks is the Write Protect Sensor.
'J10' on the new deck is the same as 'J09' on the old one. The head
'Track 00' sensor.
The wire from the R/W head is a 5 pin connector, same as the old drive,
and is long enough to work. There is a difference in colors of the
wires to which pins, but the Ground is right. I assumed the difference
in wire colors is because of a different manufacture of the head itself
and that the plug was wired correctly to work.
The last one was the Stepper Motor plug, J3 on the old one and '15' on
the new deck. A six wire connector. The stepper motors were made by
two different companies so maybe it would work as is. Also, on the Indus
motor control board, pin 6 was not used. No foil connected to it.
Here is what must be done to make it work:
1. Remove the Motor Control board from the top of the old drive. Note
that all the plugs are marked on their top side.
2. The two screws on the top right of the new drive must have the lock
washers removed so the motor control board will fit.
3. Arrange and tape the wires coming from the R/W head the same as the
old drive.
4. Now the only tricky part of this. The wires coming from the motor
are too short. On the Motor Control Board, remove the 4 wire
connector (marked J4 on the board) for the motor plug, J1. Use a
small soldering iron and a solder 'Sucker'. Turn it around so the
pins are pointing to the left and re-solder it in place.
5. Install the Motor Control Board and cardboard insulators on the new
deck, taking care to position the R/W connector and that the board
and insulators clear the top floppy idler hub.
6. Connect the R/W, 5 pin connector with the '0' up, the same as it was
on the original.
7. You will have to cut some plastic tie-wraps to free the drive motor
wires. Turn the connector UPSIDE-DOWN, so the 'J1' marking is down
and the 4 pin retaining slots are up and plug it into the connector
pins that you turned around. Be sure they won't interfere with the
head movement.
8. Run the Stepper Motor connector up through the frame as was done on
the old deck and plug into the 6 pin connector, the marking '15' up.
On mine, the 2 red wires were towards the front of the drive, pin 5
and 6.
9. Locate and clean the two mount holes on the left side of the drive
where the label is.
10. On the left side of the old drive, mark on the frame above the 3
plugs, the 'J' number found on each of the 3, 4 pin connectors as
you remove them.
11. Loose the two screws holding the front panel to the Indus frame.
On older drives, you might have to remove it as the panel
connectors on the bottom board where too high for the deck to clear
them.
12. Remove the old drive, 2 screws on each side of the frame, and lift
it out. Now is the time to fix that front door if you've had
problems with it.
13. With a screwdriver, pry off the front lever on Both drives and swap
them. The lever on the new one is too long to fit through the
front panel and work.
14. Keeping the wires clear, install the new deck, adjust it's position
and snug the two screws holding the front panel to the frame. Plug
the rear Flat Cable into the Control board.
15. There should be four connectors at the left, rear. The two wire
(J12) and the three wire (14) won't be used. Tuck these away at
the rear so the are out of the way and won't short to anything.
16. Find the connector marked J10 and plug this into the front most
pins where J09 was on the old deck.
17. Find the connector marked J11 and plug this into the rear most pins
where the old J11 was.
There, that's it. The now unused pins, J12, won't be used and isn't
needed. They were for the Timing Hole sensor. If you REALLY want to,
you Could maybe pry out the LED and sensor from your old drive and
reinstall them, but WHY? They aren't needed.
One thing I did learn from trouble shooting my problem. The Floppy
Controller Chip used is capable of controlling a Double Sided drive.
It's a Western Digital, 2797 type. Anyone need a challenge? How about
a kit for a 5 1/4 inch Double Sided, Double Density drive or how about a
3 1/2 inch drive? 80 tracks, double sided is 720K.
Richard Mier
C-Serve 73537,3573
GEnie RBMIER
=======================================================================
* LIGHT SENSOR FOR THE 8-BIT by Kevin Jones
=======================================================================
This is the first of a series of articles that will teach the average
user a little more about his computer and the lesser known talents of
the Atari computers. If this article meets with any interest then there
will be more "How to" articles following this one. Each file will
describe how to make a new hardware project for the Atari computers. If
you like this article, have any questions, or just want to complain, you
can reach me at The Atari Scene! (502-456-4292).
In this file I will describe how to make a Light Sensor. Before I get
down to the details, I will tell you how it works. The joystick port
for the Atari computer consists of 4 joystick input pins, 2 paddle input
pins, 1 negative ground pin, and 1 +5 volt pin. Right now we are only
concerned with the paddle input and the +5 volt pin. The paddle works
by a potentiometer that changes its resistance when the knob is turned.
The ATARI measures this resistance and converts it to a number between 0
and 255. The light sensor will consist of a plug for the computer port,
a potentiometer and a photocell.
The Current will flow through the potentiometer, which is used to tune
the potentiometer to a desired number,and into the photocell which will
further change the resistance. From the eye, the current will go back
into the paddle input pin on the computer. The photocell eye will
change its resistance when light shines on its surface. It works
somewhat like the pot but does not have a knob to turn.
Now that you have a minimal understanding of what you are making, we can
begin to construct the sensor.
Here is a description of the port configuration on the computer.
*1 2 3 4 5*
*6 7 8 9*
1 to 4 Joystick input pins
5 Paddle B input
6 Fire button
7 +5 volts
8 Ground -
9 Paddle A input
Parts: (1) 9 pin Female connector 276-1538 2.49
(1) CdS photocell 276-116 1.79
(1) 100k potentiometer 271-1721 1.09
Wire-about Six feet
Step One: Cut the wire into two (2) strands of two feet each. Solder
one end of the first wire to pin 9 and the end of the other wire to pin
7.
Step Two: Take the free end of the wire attached to pin 9 and solder it
to one lead of the photocell. Next, solder a wire (new wire) to the
other lead of the photocell and solder the end of that wire to an
outside pin of the potentiometer (there will be three pins on the
potentiometer).
Step Three: Take the wire from pin 7 and solder it to the inside pin of
the potentiometer.
Step Four: Basically the sensor is finished. You can either mount it in
a box or pc board, or you can tape the connections with electrical tape
and let if flop around. I would tape it and mount it in a box to be
neat and safe.
All you have to do is plug the female plug into port one and run the
below program. This program will print out the value (0-255) of the
port. All that has to be done to measure the light is to obstruct the
photocell and watch the readings. That is it!!
10 Rem Light Sensor Program
20 x=paddle(0)
30 print x
40 goto 20
That's about as simple as it gets.
=======================================================================
* LINE NOISE
=======================================================================
Many people have left messages on my bulletin board asking me why there
are so many 'garbage' characters on their screens and why file transfers
are riddled with errors. These garbage characters are really line noise
and can be introduced in many different places. Pure noise is a decimal
255 (FF inhex), but most line noise is not 'pure'. It usually comes in
as something less than 255, like maybe a 251 (a character that looks
like this ''). Ever see that one before? Yup, so have I!
One of the more common and familiar introduction points of line noise is
in the telephone company's system and even here there are several ways
noise is introduced. A signal is routed through multiple stations
before it eventually makes it to the other end and some of these
stations aren't exactly new. Older areas may have older, less
sophisticated equipment that is more apt to be affected by ambient
noise. This is one reason some people continue to have noise problems
even after hanging up and calling back multiple times. Also, a given
physical connection at one of these junctions may not be up to snuff.
If your particular bout of line noise is solved by hanging up and
calling back, then it's probable that you were previously connected
through an intermittent or 'dirty' connection. Some of these trunk
lines (large, multi-area that has a lot of ambient RFI (Radio frequency
Interference) present although this is not usually the case.
It is possible that the problem is being caused at this end, but not if
the problem goes away when you call back and the line is clean -or- if
you are one of a very few users experiencing noise problems. You may
say that you are not having problems with other boards.....in which case
the problem is more than likely the route that your call takes to get
here. You may be going over micro-wave or through buried cable which
for some reason are sub-standard. No matter how many times you call,
you will probably be routed over the same path. Microwave problems are
sometimes the hardest to track down because they can cause intermittent
problems. Some interference only occurs during certain times of the day
or week.
Another common noise introduction point is in your home. Most
residential homes have televisions, radios, microwave ovens, VCR's, and
if you are reading this, a micro-computer. All these devices radiate
radio waves that can (and often do) get into the phone lines and cause
noise. Electric motors and technical dimmer controls can introduce
noise into the electrical wiring in your house and cause problems. If
your line noise problem does not go away after repeated hanging up and
calling back, then you may be suffering from one of these household
problems. If you are suffering from this problem, you can take steps to
eliminate it. First of all, turn off EVERYTHING except the fridge (If it
IS the fridge, then you're SOL. Can't live life with your ice box
unplugged) and see if the noise persists. If it goes away, then start
turning things back on, checking the computer each time until you see
the noise start up again. It may be that a single device is not bugging
you but several devices plotting together to annoy you. This
elimination tournament may take awhile.
Another area to check is your wiring at the computer. Use noise
supressers on your power connections to both the PC and the modem (if
external). Use a shielded RS-232 cable to connect your modem to the PC.
Ribbon cables (especially long runs of it) are great antennas and will
cause problems. Re-route the RS-232 cable so it does not run next to
the PC power supply or any other transformer.
And now a little discussion about the modem itself. First of all, I'd
like to clarify a commonly misused term - BAUD. The term "Baud" is
actually a man's name - J.M.E. Baudot (Pronounced: Baw-doe) a French
Telegraphy expert. 1,200 and 2,400 Baud is NOT the same as 1,200 and
2,400 BPS (Bits Per Second). The usage of "Baud" to describe line speed
in terms of data through-put is incorrect. 1,200 and 2,400 BPS modems
both operate at 600 Baud. Basically, without getting to technical, a
Baud is a "blip" of information. 1,200 BPS modems use four states per
blip (or Baud) and 2,400 BPS modems use sixteen states per blip. If you
want more information on what Baud and BPS mean and a full explanation
of how data is actually represented and transferred by the modem, please
refer to PC Magazine Volume 6, Number 9 (May 12, 1987).
Modems operating at 2,400 BPS are much more intolerant of line noise
than are modems operating at 1,200 BPS. Conversely, modems capable of
2,400BPS operate better at 1,200 BPS than do 1,200 BPS only modems. If
you are being hopelessly attacked by noise at 2,400 BPS, trying calling
back at 1,200 BPS. It's very possible that the noise will be greatly
reduced or disappear altogether. I know, you didn't buy a 2,400 BPS
modem just to retard it to 1,200 BPS. The brand of the modem plays a
part in the immunity to line noise. Some modems can digest more noise
(lower signal-to-noise radio) than others. PC Magazine (same issue
mentioned above) ran a test on 87 different modems. You might check the
results to see how your modem ranks. Most 2,400 BPS modems operating at
1,200 BPS have approximately -8 to -10 db error threshold while the same
modem has about -16 to -20 db threshold operating at 2,400 BPS. For
this reason, line quality is much more critical at 2,400 BPS operation.
Additionally, a friend of mine who runs a bulletin board from their
office has been plagued with line noise problems at 2,400 BPS but very
little noise at 1,200 BPS. The culprit is the office's centralized
telephone system. Many office buildings have a given number of trunks
that actually enter the building while there may be many, many more
extension within the building. These types of telephone systems have
their own controllers and line assignment devices and are frequently not
as high in quality as a hard-wired MaBell (or GTE) line. The acceptable
signal-to-noise ratio in some of these inter-office phone controllers
are lower than necessary for reliable 2,400 BPS operation but not too
low for 1,200 BPS.
If you get transmission errors while downloading or uploading a file,
don't fret it. The Xmodem (or whatever protocol) incorporates an error
checking/correction mechanism that automatically detects and corrects
any errors that may occur during transmission. The very fact that
Xmodem reported the error in the first place means that he caught it and
corrected it. The only errors you have to worry about are the ones that
Xmodem does NOT report. Any reported error has already be corrected.
Xmodem, especially the CRC flavored one, is a very reliable file
transfer protocol. Even if you got 100 errors during transmission,
chances are still pretty slim that the file got corrupted.
Occasionally, a file will be corrupted after transfer, but many times
this may be due to a bad ARCing of the file or perhaps a disk error that
may have occurred sometime during the files' past.
=======================================================================
* Z*MAGAZINE ARCHIVES - 1987
=======================================================================
#: 201366 S3/Utilities 15-Dec-87 03:04:41
Sb: #201344-#mess.fix
Fm: Bill Wilkinson [OSS] 73177,2714
To: MR GOW 73167,3607
There is NO program that can GUARANTEE to fix a disk when you get an
error 164.
An error 164 usually results when you have two files trying to use the
same spot on the disk. This usually happens because you have saved one
file to disk, done something illegal, and then saved a second file to
the same disk. The second file is probably okay and is probably
completely accessible. But the first file is simply GONE because the
second file has written over the top of it. Period.
Can you recover part of the damaged file? Possibly. But I would
suggest that unless it is a text file (e.g., a word processing data file
or possibly a LISTed -- NOT SAVEd -- program) the effort is bound to
fail. Most SAVEd files, whether binary files or BASIC programs, simply
CAN NOT be restored if they are missing pieces. Sorry.
Having said all that, what CAN you do with a damaged disk? Well, the
DISKFIX utility that is part of DOS 2.5 will at least TRY to recover as
much of a disk as it can. But if it decides a file is damaged beyond
repair, it simply removes the file from the directory! So I would
recommend making a sector copy of any damaged disk before attempting to
use DOS 2.5's DISKFIX.COM program.
You can get DISKFIX here on CIS, in the DL's (DL 3, file DISKFI.*). But
I personally recommend that you send off to Atari for a copy of not only
a disk with DOS 2.5 but also a really good manual. The manual alone is
worth the $10 or so that Atari charges.
Finally: The Atari DOS manual suggests this program to recover as much
as possible of a damaged file, so long as the file is not bigger than
available RAM in your machine:
10 PRINT "INSERT DAMAGED DISK THEN GIVE NAME OF FILE TO RECOVER ";
20 F=FRE(0)-300 : DIM BUF$(F),FILE$(20)
30 INPUT FILE$
40 OPEN #1,4,0,FILE$
50 TRAP 100
60 FOR I=1 TO F : GET #1,B : BUF$(I)=CHR$(B)
70 NEXT I
80 PRINT "FILE TOO BIG"
90 END
100 REM GET HERE ON ERROR...
110 TRAP 120 : CLOSE #1
120 PRINT "INSERT FORMATTED DISK THEN GIVE NAME TO SAVE FILE TO ";
130 INPUT FILE$
140 OPEN #2,8,0,FILE$
150 PRINT #2; BUF$ ;
You could be neat and add line 160:
160 END
Finally, line 150 might be safer done as:
150 FOR J=1 TO I-1 : PUT #2,ASC(BUF$(J)) : NEXT J
OOPS...One more finally.
In one of my articles in COMPUTE in that last year, I discussed probable
causes of messed up disks. I noted that I personally have virtually
NEVER had a disk messed up by DOS. Reason: I never never never change
disks unless the program tells me to do so. If I am changing disks
while using BASIC, I always type "END" before doing so. In desperation,
I will hit RESET before changing.
The single most common cause of disk crashes is inserting a new disk
while a file (or files) is still OPEN for output on the first one. This
can happen with word processing programs, data bases, etc., etc. ALWAYS
WAIT for the program to tell you it is time to swap disks. ALWAYS use
the menus to get to the "disk change" point. NEVER just yank a disk and
plunk in a new one.
=======================================================================
* THE HISTORY OF ATARI ..a continuing saga...
=======================================================================
Date: 27 Dec 91 21:59:20 GMT
From: psinntp!ultb!ultb!clf3678@uunet.uu.net (C.L. Freemesser)
Subject: History of Atari
To: Info-Atari8@naucse.cse.nau.edu
In article <1991Dec27.041613.9166@crash.cts.com>, trag@pnet01.cts.com
(Jim Trageser) writes:
>I'm writing a story on the history of Atari for San Diego's
Computer Edge magazine; deadline is 12-29. I'm strong on the 400/800,
but fuzzy on other areas. Was the 2600 video game machine Atari's
first home market product? And I know you can get a 2600 adapter for
the 5200, but am lost completely about the 7200.
>Also, what differentiated the XE/XLs from the 400/800? How much
compatibility was there? Are any still manufactured?
The Atari 2600 was not Atari's first home video game system. They had
at least 3 machines before the 2600, but all of them were variations on
PONG. Also, they did not have cartridges, but had their game programs
built in. The 2600, which came out in 1977 or so, was the first video
game system with interchangeable game programs. As I'm sure you
remember, it was a VERY popular game machine, and still remains in
production today. The Atari 5200 came about in late 1981 or early 1982.
It was basically an Atari 400 computer with only cosmetic differences.
However, it suffered from poor joysticks. It did have an optional
accessory to let you plug in 2600 cartridges, as well as an optional
track ball controller unit. The machine did feature a numeric keypad on
the controller, as well as a pause button. The Atari 7800 came out
around 1984, when the market was collapsing. Designed by General
Consumer Electronics for Atari, it was like a "turbo 2600". Not only
could it play all 2600 games, but also had extended graphics and sound
for 7800-specific games. It used joysticks identical to the 2600, but
which had 2 different buttons on it. It was shelved during the
transition from Warner to the Tramiel family, and was reintroduced
around 1986. It is still manufactured today, with new games still
coming out for it. Technologically,it is superior to the Nintendo and
the Sega Master System, but suffered from poor timing and the lack of
advertising that all Tramiel-introduced Atari products.
As for the difference between the 400/800 and the XL/XE systems, The
XL/XE have a built-in BASIC (the 400/800 had a cart), slightly different
keyboard, and added features in BASIC. The XL/XE also have a parallel
bus interface and a HELP key, which the 400/800 did not have. The 800
was the only computer with TWO cartridge ports.
Hope this helps!
__\ Chris Freemesser, RIT Comp.Eng.Tech. Dimension's End BBS /__
___\ BITNET: clf3678@ritvax (716)436-3078 /___
____\ Usenet: clf3678@ultb.rit.edu 1200/2400 baud, 130MB /____
_____\ GEnie: C.FREEMESSER STark BBS software /_____
======================================================================
* ADVENTURES IN STRUCTURED PROGRAMMING by Michael Stomp
======================================================================
All of the columns on Structured Programming techniques, originally
appeared in The ACCESS Key, the newsletter of the Atari Computer Club
Encompassing Suburban Sacramento. These articles may be freely
reprinted, provided source credit is given. The files are unformatted
text files.
If you wish to contact me, write to:
The ACCESS Key
P.O. Box 1354
Sacramento, CA 95812-1354
Michael Stomp
Oct. 14, 1981
VI. GOODBYE GOTO
Let's say you have studied the previous three articles and have broken
your program into modules according to one or more of the design
methods described. Now you are ready to start writing the individual
modules as procedures and want clear, untangled code that takes full
advantage of the extended commands of a structured language such as
TURBO BASIC XL. How should you go about it?
I would say that the secret lies in GOTO statements; don't use them.
You don't need them. After all, many languages, such as ACTION! don't
even have a GOTO statement or anything like one. While there are
occasions when one could make an argument for using a GOTO, in general
their overuse is the prime cause of tangled coding. Let's examine some
cases and see how GOTOs can be eliminated.
IF - ELSE - ENDIF
GOTOs commonly occur two ways; by themselves or in IF statements,
either explicitly or implicitly. One common sight in Basic programs is
something like this:
1020 IF X=0 THEN Y=3:GOTO 1100
<stuff done if X<>0>
.
1100 <continue on>
The new form of the IF statement in TBXL allow us to eliminate the GOTO
with:
1020 IF X=0
1030 Y=3
1040 ELSE
1050 <stuff done if X<>0>
.
1090 ENDIF
11OO <continue on>
This makes it very clear that we are doing an alternation, and just
what the two alternatives are. To make things clear in the original
version, draw a box around the statements following the IF up to the
target of the GOTO, however far that might take you. That's what goes
after the ELSE statement and before the END IF. If nothing is done
when X=0 except the GOTO, one can negate the test like this:
1020 IF X<>O
<stuff done if X<>0>
.
1090 ENDIF
1100 <continue on>
WHILE - WEND
If the pattern of GOTOs looks like this:
1020 IF X=0 THEN 1100
<done if X<>0>
.
1090 GOTO 1020
1100 <continue on>
Here there is a second GOTO which jumps back up to the IF statement.
Obviously, what we have here is a loop, so why not write it explicitly
as a loop? Of course, something in the lines between 1020 and 1090 had
better change X so that eventually it becomes zero or we will never get
out of this loop! We will execute those statements as long as X<>0, or
'while' X<>0. Obviously, what we need to use is the WHILE statement:
1020 WHILE X<>0
<done if X<>0>
.
1090 WEND
1100 <continue on>
We negated the test in the IF statement, from 'IF X=0...' to 'WHILE
X<>0', and marked the end of the statements in the loop with 'WEND'.
There are three things to notice about the WHILE loop:
1) X must be given a value BEFORE we start the loop.
2) If the loop is ever to terminate, something in its body must change
X so that it eventually becomes zero.
3) The loop may not be executed even once, depending upon X.
Of course, the same things are true when the loop was done with GOTO
statements.
REPEAT - UNTIL
You ought to be able to see the next example coming:
1020 .
.
1090 IF X=0 THEN 1020
1100 <continue on>
Again we have a jump backwards, so we must have a loop, one that
continues 'until' X becomes nonzero. The translation is:
1010 REPEAT
1020 .
.
1090 UNTIL X<>0
1100 <continue on>
As in the case of the WHILE statement we negated the test in the IF
statement. Again, there are three things to notice:
1) X need NOT be given a value before starting the loop.
2) If the loop is ever to terminate, something in its body must change
X so that it eventually becomes nonzero.
3) The loop will ALWAYS be executed at least once, no matter what X is.
DO - LOOP
The next form is a bit more complicated in the pattern of GOTOs:
1020 .
.
1050 IF X=0 THEN 1100
.
.
1090 GOTO 1020
1100 <continue on>
Again there is a jump backwards, so we have a loop, but this time we
exit the loop in the middle. The translation is:
1010 DO
1020 .
.
1050 IF X=0 THEN EXIT
.
.
1090 LOOP
1100 <continue on>
The DO...LOOP by itself will never terminate; it is the EXIT command
that breaks us out of it. (Note that this time we did NOT negate the
test in the IF statement.) The WHILE loop makes the loop test at the
beginning; the UNTIL loop makes the test at the end; and the DO loop
makes the test in the middle, breaking the loop into two parts. Again,
there are three things to note:
1) X need NOT be given a value before entering the loop, but must be
given a value in the first part.
2) If the loop is ever to terminate, something in either part one or
part two must change X so that it eventually becomes zero.
3) The first part of the loop is always executed; the second part may
not be executed even once.
EXIT TO THE RESCUE
The EXIT command can be used to get out of any of the other kinds of
loops, including FOR...NEXT loops. This can be handy for solving some
types of programming problems that can arise. For example, consider
the following loop:
1000 J=1
1010 WHILE J<=LEN(A$) AND A$(J,J)<>" "
1020 J=J+1
1030 WEND
1040 IF J>LEN(A$)
1050 ? "No blank space"
1060 ELSE
1070 ? "Space at position ";J
1080 ENDIF
This loop searches A$ looking for the first blank space, so we remain
in the loop as long as there are characters yet to check and we haven't
found a blank. It should work, but it doesn't; the problem lies in the
test in the WHILE statement in the case A$ contains NO blank. When J
becomes greater than the string length, the first clause is false, so
the second clause doesn't matter; the whole condition is false.
Unfortunately, the Basic interpreter (as well as the ACTION! compiler)
isn't smart enough to recognize that, and tries to evaluate the second
clause: [A$(J,J)<>" "]. But now J exceeds the string length, causing
an error. (For some strange reason you get Error #12, Line Not Found,
instead of the more logical Error #5, String Length Exceeded. Just to
keep us confused, I guess. A similar thing happens with numeric
arrays.) Obviously, we must break the loop test into two parts. But
how? Use nested WHILE loops? (I'll let you figure out why that won't
work.)
As you might guess from the title of this section, our salvation comes
from the EXIT command:
1000 J=1
1010 WHILE J<=LEN(A$)
1015 IF A$(J,J)=" " THEN EXIT
1020 J=J+1
1030 WEND
1040 IF J>LEN(A$)
1050 ? "No blank space"
1060 ELSE
1070 ? "Space at position ";J
1080 ENDIF
We add an IF statement with the second clause of the loop test negated,
and EXIT if true. When we reach line 1015, J can never be greater than
the string length, for the test in the WHILE statement would have
already terminated the loop if that were the case. A similar problem
with a test in an UNTIL statement is hand led in a similar way; an IF
statement, exiting the loop if the string length is exceeded, is
placed right before the UNTIL statement, and the test in the UNTIL
statement will only contain the second clause of the entire test.
Using these techniques for transforming various patterns of GOTO
statements you find in a program should result in clearer structured
code. I am sure, however, that you could find some examples of
programs so tangled that it might be very difficult to see the
underlying structure. Those are probably programs with some nasty
logic bugs lying in wait. Even more reason to try to untangle the
snarl.
A final word of advice: When you print a listing of a Turbo Basic
program the various loops, IF...ENDIFs, and procedures will be indented
two spaces each. This makes it easy to see, in a graphical manner,
just where structures begin and end, and whether you have properly
closed out everything. That is, if you haven't put too many things on
the same line! Each WHILE, REPEAT, DO, WEND, UNTIL, LOOP, as well as
each IF, ELSE, and ENDIF should be put on a line by itself. In that
way, you get full advantage of the indenting. You can lay a ruler
vertically on a print-out and connect the beginning and end of each
structure, and see if you have them properly nested and terminated.
Some people like to crowd as many statements as they can on each line,
hoping to save a little RAM. It is better to get the program right
than to worry about a trivial economy of memory, and a clear listing is
a great help in getting it right. If memory is tight, reduce the size
of some arrays until you get the bugs out and the program running
correctly. Then go back and pack multiple statements on each line, if
you must. But there are more effective way to squeeze out more memory.
To sign up for DELPHI service, call (with modem) (800) 695-4002. Upon
connection, hit <return> once or twice. At Password: type ZNET and
hit <return>.
To sign up for GEnie service call (with modem) (800) 638-8369. Upon
connection type HHH and hit <return>. Wait for the U#= prompt and type
XTX99436,GEnie and hit <return>.
To sign up for CompuServe service call (with phone) (800) 848-8199. Ask
for operator #198. You will be promptly sent a $15.00 free membership
kit.
Z*Net International Atari Online Magazine is a weekly publication
covering the Atari and related computer community. Material published
in this edition may be reprinted under the following terms only. All
articles must remain unedited and include the issue number and author at
the top of each article reprinted. Reprint permission granted, unless
otherwise noted, to registered Atari user groups and not for profit
publications. Opinions present herein are those of the individual
authors and does not necessarily reflect those of the staff. This
publication is not affiliated with the Atari Corporation. Z*Net, Z*Net
News Service, Z*Net International, Rovac, Z*Net Atari Online and Z*Net
Publishing are copyright (c)1985-1992, Syndicate Publishing, Rovac
Industries Incorporated, Post Office Box 59, Middlesex, New Jersey,
08846-0059, Voice: (908) 968-2024, BBS: (908) 968-8148, (510) 373-6792.
Z*NET: Atari ST Online Magazine
Copyright (c)1992, Rovac Industries, Inc...
-----------------------------------------
Return to message index
