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:
                           Post Office Box 59
                    Middlesex, New Jersey 08846-0059
                         Attention: Stan Lowell
 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 Corps Mike Groh will be in attendance at the Hawaiian User Group
 Show.  Also in attendance will be Impact Marketing.
 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
 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 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.
 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.
 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.
 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
 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
 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.
 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.
 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
 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!
 Jeff McWilliams
 2001 G Woodmar Drive
 Houghton, MI  49931-1017
 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
 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
 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
 * 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
 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
 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.
 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.
  #: 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 $10 or so that Atari charges.
 Finally: The Atari DOS manual suggests this program to recover as much
 as possible of a damaged file, so long as the file is not bigger than
 available RAM in your machine:
 20  F=FRE(0)-300 : DIM BUF$(F),FILE$(20)
 40  OPEN #1,4,0,FILE$
 50  TRAP 100
 60  FOR I=1 TO F : GET #1,B : BUF$(I)=CHR$(B)
 70  NEXT I
 90  END
 110 TRAP 120 : CLOSE #1
 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:
 P.O. Box 1354
 Sacramento, CA 95812-1354
 Michael Stomp
 Oct. 14, 1981
 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.
 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
  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>
 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
 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.
 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.
 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$(J,J)<>" "].  But now J exceeds the string length, causing
 an error. (For some strange reason you get Error #12, Line Not Found,
 instead of the more logical Error #5, String Length Exceeded.  Just to
 keep us confused, I guess.  A similar thing happens with numeric
 arrays.)  Obviously, we must break the loop test into two parts.  But
 how?  Use nested WHILE loops?  (I'll let you figure out why that won't
 As you might guess from the title of this section, our salvation comes
 from the EXIT command:
  1000 J=1
  1010 WHILE J<=LEN(A$)
  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
 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.

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