Z*Magazine: 6-Jun-89 #160From: Atari SIG (xx004@cleveland.Freenet.Edu)
Date: 09/25/93-04:13:54 PM Z
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From: xx004@cleveland.Freenet.Edu (Atari SIG) Subject: Z*Magazine: 6-Jun-89 #160 Date: Sat Sep 25 16:13:54 1993 | ROVAC ZMAGAZINE | | Issue #160 | | June 6, 1989 | |Copyright 1989, RII| |This week in ZMagazine| Atari Announces New Products ZBreak #5 Summer CES Chicago June 3, 1989 <<<< Kirk >>>> Hard Disk Hints (Part 2) W. K. Whitton The Master Memory Map Jerry Cross Electronic Mailbox At Home Bob Fasoldt |ATARI ANNOUNCES NEW PRODUCTS AT CES| Z*BREAK #5 EXCLUSIVE CES REPORT June 3, 1989 Copyright (C)1989 Rovac Industries, Inc The following report comes direct from our ST*ZMAG/Z*Net correspondents Mike Letchkun and Brian Wilmoth live in Chicago for the annual Consumer Electronics Show. At noon today, June 3, 1989, Sam Tramiel called a news conference and announced the release of the first Atari portable Color Arcade System. This 3 1/2 inch LED video game system measures approx 11 X 4 X 2 and weighs about 1 pound. 16 colors on a 160 X 102 screen. Retail price is set at $149.95. Atari is releasing the product in conjuction with Epyx and debuts with the following game cartridges: Impossible Mission, Blue Lightning, Time Treasure Chest and a few others. The unit has 4 channel sound and Comlink. Comlink is an output via RCA phono jack and allows simultaneous play with up to 8 portable units. The portable game system runs at 16MHZ with 6 AA batteries. Another feature is the ability to press two buttons at the same time to reverse the screen for left-handed players. There were 5 units on hand for show attendees to play with. An additional game called California Games will be available with the full four part version. This announcement has been kept secret until today's show. Software prices will range between $20 and $30.00. At the Atari Booth, 8-bit software was shown: Deflecktor and Xenophobe, along with the first look at MidiMaze from Xanth. This configuration consists of SIO cables to 3 outputs. Midi I/O is dedicated to the game. The 7800 was on hand with new releases that include Commando, Tower Topple, Double Dragon, Jinx, Xenophobe, and Shooting Arcade. The 2600 was also shown with Road Runner, Double Dragon, Rampage, BMX Simulator, and Radar Lock. The PC4 286 was shown with the 3 1/2 and 30 meg hard drive. We were told that FCC approval is still lacking because of the case configuration. However, Atari was still making the official domestic release at this show. Lastly, Spectrum Holobyte announced a new missions disk for Falcon. They will be released in July. The PC and MAC will be getting attention in the game area before the ST. The first port-over will be VETTE. VETTE is a driving simulator which takes you through the streets of San Fransisco. |SUMMER CES CHICAGO JUNE 3, 1989 | |by <<<<Kirk >>>>| Atari introduced a new portable COLOR game system today. This unit is about the size of of VCR tape, yet only weighs one pound, and includes a built-in 3 1/2 inch color screen. On the left side of the unit is a built-in 8 direction joypad, and on the right side is a set of four buttons for game control/firing. An additional option is the ability to flip the image on the screen so that the unit can be held with the joypad in either hand, allowing for comfortable use by left handed people. The following is a list of features: * 16MHZ (not a typo) 65c02 microprocessor * 16 simultaneous colors from a pallet of 4096 * Game cards as large as 2 Megabytes (current cards at 128K bytes) on the size of a credit card * ComLink: communications port allowing up to 8 machines to be linked together for simultaneous play * Headphone jack for private listening * Runs on 6 AA batteries (about 6-8 hours) or AC adapter * 6 games announced for this new machine by Eypx Suggested price: $149 Available by September? Also at the show were the 80286 8MHZ PC clone from Atari as well as several 'Portfolio' hand held computers (however, the portfolio had no specific display for themselves--they were being carried by some of the Atari representatives). Other than that the display was composed mainly of 2600s, 7800s, and XEGSs, and a display of Atari brand calculators. A demo of MidiMaze was being shown on the XEGS, as well as a version of Tower Toppler. |HARD DISK HINTS (PART 2)| |W.K. Whitton| Reprinted from ST-ZMagazine #23 The Ins and Outs of Interleave or "A Thousand and One Practical Uses For Thin & Crispy Pizza" Although there is an abundance of computers complete with various and sundry operating systems, one thing is common to them all. They all use magnetic media of some sort (CD systems notwithstanding!). They rotate the media at speeds from 300 rpm all the way up to 3600 rpm, and disks can readily be found in sizes from 3 1/2 inches up to 8 inches in diameter. These systems store their data on these disks by means of flux changes in the magnetic coating on the surface of the media. The most common material used in the construction of a floppy disk is "Mylar", and has a coating of ferro-magnetic particles implanted on both sides. The data is written to this media in circular patterns, much the same way a record album is written. It does does differ somewhat though as the data on an LP is more like a spiral, while the data on a disk is comprised of smaller and smaller concentric circles. Another difference between the two is that the LP spins at 33 R.P.M.; the floppy disk spins at 300 R.P.M. (or in some systems, 360 R.P.M.) The floppy disk, depending on several factors, can save from 160 thousand bytes (called 160K) to almost a million and a half (1.44 Megabyte). Another popular storage medium for computers is the hard drive. Hard drives use platters, which are round just as floppies are, and likewise contain data on both sides of the magnetic media. But, these spin at a much faster rate (3600 rpm on the average), possess the ability to hold quite a bit more data (5 Meg on up to over 600 Meg), and are not flexible nor removable as the floppies are. In the late 70s and early 80s it was common to see hard drives which had the capacity of 5 Meg. These technical marvels of the day were single platter mechanisms, and a paltry 160 tracks compared to today's standard. Hard drive technology has greatly advanced since that time, and it is commonplace to see advertised multi-platter, thousand track drives. These massive storage devices are ordinary rather than extraordinary both in price and availability. We can safely say that the computers we now have to use, abuse, and enjoy, with their "Megs" of RAM, multiple "Megs" of hard drive storage space, and much faster CPUs, such as the Atari Mega ST computer system with optional hard drives, in many ways rival the large commercial systems of the late 70s in cost, performance, and storage capacity. In order to understand a little better what we are going to discuss, you will need to visualize what the sectors appear to look like on a disk. Imagine going to your local Pizza Hut and holding a user group lecture. You order a large thin and crispy pizza with everything on it (stop drooling!) for your demonstration, and tell the waitress to not cut the pizza. Take the pizza cutter and divide the pizza into 17 equal slices, but leave them in the tray as they were. Now, you pull a bag from under the table. In it you have donut cutters you swiped from the local donut shop. You proceed to recut the pizza, starting at the middle with a tiny round cutter, and proceeding with a larger diameter cutter each time. What we have done thus far is slice the pizza (into sectors), and cut it with the donut cutters (into cylinders or tracks depending on your vocabulary), and ended up with quite a few pieces of pizza that resemble miniature half-moons. Let us say these little half-moons of heavenly cuisine are equal to 512 bytes on your hard disk. You could then easily calculate the total storage capacity of your storage device by multiplying and using this formula: storage capacity = 512 x total # of sectors. Now if you really wanted to go all out, you could have purchased 4 or 5 pizzas, stacked them on top of each other, and ended up with a true approximation of what a multi-platter hard drive looks like. If realism was extremely important, then you could instruct them to put the toppings on BOTH sides of the pizza (weird!). In a real hard drive, each of these separate platters is read by its own individual head. The only thing I would recommend here is instructing the Pizza Hut crew to put your "data concoction" in the microwave, and order a LARGE pitcher of pop...while you are waiting, you may wish to calculate the total storage capacity of the "crispy drive" you just constructed. The formula is: capacity (in bytes) = sectors per track X tracks on each platter X total number of heads. Let us leave our pizza analogy behind. As the hard drive merrily spins along at 3600 rpm, the sectors are passing by the read/write head. The speed at which the bits pass by is found by calculating 17 sectors, and 512 bytes per sector, at a speed of 3600 rpm...hmmm...that comes out to 31,334,400 data bytes per minute, or 4,177,920 data bytes per second. One thing you should note is that each sector contains "control information" which is in addition to the data you stored on the device. Its purpose is to allow the controller to actually be able to access the data, so the real-time data transfer rate is actually a little higher than what you calculated (5 Megabits per second is a very safe guess). Interleave can be best expressed as the the sequence of physical sectors on a hard disk as it relates to the logical sequence of the sectors. The interleave factor (such as 1:1, 4:1 etc.) can be defined as the number of times the disk must revolve in order to read all the sectors on the disk, in order, from the first sector to the last. An interleave of 1:1 is the fastest possible, meaning it reads one entire track in one revolution of the platter. Lets us take a typical WordWriter II text file, such as the one comprising this very article. An average short article by yours truly is usually about 5K long. This means that this file takes up 10 sectors on the hard drive, as each sector is 512 bytes wide. What is known as the first logical sector is that part that contains the first part of our file in question, while the last logical sector of course contains the last part of our text file. Let us, for illustrative purposes, say that the first logical sector happens to be 4,50. The next record won't necessarily be 4,51 as you might suppose, but rather, this is determined by the interleave of your hard drive. If the interleave is 1:1, then this means the physical sectors are laid out in such a manner as to make them equal to the logical sectors. This means the data would be laid out like this: 1_2_3_4_5_6_7_8_9_10_11_12_13_14_15_16 If the interleave is set at 2:1, then the second logical sector would appear at 4,52 , the next at 4,54 and so forth. The data on an "interleaved drive" is laid out a bit differently than 1:1, one drive had the data laid out like this: 1_10_2_11_3_12_4_13_5_14_6_15_7_16_8_17 Can you guess what interleave this represents? Now, if we wrote after sector one, sector five, and after two we placed sector (an interleave of 4:1), it will take 4 revolutions of the platter to read in all 17 sectors of the drive. This is not a data rate of 500K, but it is much, much faster than attempting to read the same data one sector per spin!!! The optimal placing of data on your hard drive for fastest data transfer rates is what interleaving is all about. Since some computers and controllers cannot reliably read and write data as fast as the current interleave is set, and an interleave that is set wrong will drastically slow your I/O down, and in some extreme cases the integrity of your data may be threatened, this is an important factor you must give some thought to in order to get peak performance from your system. A good case is a clone that was just in the shop I am employed at. After completing the repair, I noted the hard drive acted as if it was extremely sluggish. After a few investigative tricks, I determined that that interleave, currently at 6:1 or thereabouts, was not proper for an optimized system. I used a fine utility I received from GEnie, called Interleave (strange as it may seem), to change the current value on this system. The utility will actually change the interleave, a sector at a time, and then replace it on the newly laid out track. After 4 hours or so, that task was completed, and the owner of the system called back to thank us for the unbelievable speed increase he noted! I remember the words "Better than new!" Of course, his drive formatting software did not attempt to find out what interleave was best for his system when the hard drive was lasted formatted. Please note that the program mentioned is for the IBM-type machines--no similar interleave changer is available for the ST. How is the optimal interleave determined for your system? If you purchased your hard drive system already assembled, such as those systems from Atari, Supra, and ICD, then they have determined what is best for your system. If you pieced your system together from various components, whether purchased locally or the mail order route, then you were the one who did it, although quite possibly, unknowingly! Finally, since we can not at this time change the interleave on the Atari ST (or 8-bit systems, either) other than by totally reformatting the drive, and thereby losing all your data, >please< plan the layout and interleave of your drive before proceeding with your original formatting of your hard drive. You'll save a lot of time later on! (The ST is quite capable of 1:1 interleave...and this setting is used by ICD and other interfacing equipment.) Note: As a matter of information, some RLL drives does not conform to the 17 sector format, but rather they do things a bit differently on these drives/controllers, so not all of the above information is totally correct in the case of a few drives of this type. I'll spare you the details to avoid confusion! |THE MASTER MEMORY MAP| |by Jerry Cross| Reprinted from the June Great Lakes Atari Digest While stumbling around the Disneyland World of Atari show, I came across an interesting book at the BEST Electronics booth. Big deal, another Atari book you say? Have you taken a trip recently to your local book store in the area mall? Ever look at the computer book section? Atari books are extremely scarce. If you look really close, stuck someplace near the top of the shelf, in the middle of a bunch of Apple books, you just MIGHT find a manhandled copy of one of the COMPUTE! books still available, but I wouldn't bet on it. If you do find an Atari book, it usually falls into one of three categories: "Strictly Beginner", where the author simply took common information from the Atari Basic handbook and added a few samples; "Topic Specific" such as machine language, graphics, or some other topic that is pretty worthless to a beginning programmer; and "Hard Core Handbooks" like Mapping the Atari, De Re Atari, or other technical handbooks. This category goes way over the heads of beginners. There are very few good books for an intermediate programmer, one who is more than a beginner, but not ready yet to probe the "internals" of computer programming. That's why I was so impressed with this book. "The Master Memory Map" is very similar to Mapping the Atari. Basically, it looks at how a beginning programmer can use the POKE command to enhance their programs to include some of those special effects and "nifty-keen" tricks like turning off the break key or protecting your software. But unlike Mapping the Atari, this book was written in very easy to understand language, so that beginning programmers can understand it. Ask a beginner what a "vector" is. How about a "buffer". No, it's not a naked swimmer. The problem with most of the reference books on the market is that they assume you already know what these terms are. But The Master Memory Map assumes you don't, so you will get a lesson each time you come across one of these strange terms. This is especially true in the beginning of the book, but as you work your way through the book they slack off the "lessons" and get into the real use of the particular memory location. This book will take the beginning programmer through most of the important (and useful) memory locations, and explain in simple lessons how they can be used to enhance their programs. It will tell you if a location is for the more advanced user, but still explains it's use. By doing this, the beginner learns how that memory location is used by the operating system. This was not done with Mapping the Atari, which simply gave you a brief description of that memory location. This can be an extremely useful lesson for those folks who plan to move on to machine language in the future. Here's an example. Here is how both books describe memory location 124 (HOLDCH): Mapping the Atari A character value is moved here before the control and shift logic are processed for it. Master Memory Map A character that has been typed in from the keyboard goes here so the OS (operating system) can check out just what kind of character it really is (CTRL, SHIFT, etc.) Now, if you were a beginning programmer, which version would be easier to understand? It's like this throughout the entire book! Sources for much of the information comes from such famous books as DE RE Atari, DOS Listing, Inside Atari DOS, Hardware Manual (from Atari, Inc.), Mapping the Atari, and OS Listing (also from Atari). The authors have taken the best examples from all of these books, and compiled them into an excellent textbook for the beginning programmer. And just like Mapping the Atari, this book covers nearly all of the operating systems, CIO routines, and much, much more. However, this book seems to be a little out of date, and does not include some of the memory locations used with the XE series of computers. It does cover some of the special memory locations of the 1200XL if you are one of the unfortunate people still using this "white elephant". I do not know if your local book store can order this book. I made a call to the local B. Dalton book store and was informed that none of their suppliers had it. I suggest you contact Best Electronics or the book's publisher. The cover price is $15.95 but might be cheaper from Best. The Master Memory Map Craig Patchett and Robin Sherer Reston Publishing Co, Reston, Virginia Best Electronics 2021 The Alameda, Suite 290 San Jose, CA 95126 408-243-6950 |ELECTRONIC MAILBOX AT HOME| |by Bob Fasoldt| Reprinted from the June Great Lakes Atari Digest More and more people are buying personal computers and a fair percentage of them are purchasing modems. Electronic mail is not just a thing of the future or just for the wealthy. You can set up your own "electronic mailbox" and receive mail while away from home or sleeping! Let me explain... I live in Florida and the rest of my family is scattered across the Eastern United States. Many of my family members own personal computers and modems so we send text files to each other instead of letters...and the best news is that it is often less expensive than the mail service. I have been communicating with my family for about two years in this fashion and find it highly reliable and rewarding, plus it is immediate! When I get up in the morning, the first thing I do is turn on the monitor to see if any E-mail has come in. If so, I immediately save it to floppy, even before I read it so nothing can happen to it. At first, we were using MPP 1000's because their software supported unattended downloading. But soon I grew tired of 300 baud and purchased the Supra 1200AT which also supports unattended downloading. That software however did not support the 512K RAMdisk on my XE, so I began to look for other software for this purpose. In my opinion, Keith Ledbetter's Express! is by far the best telecommunications program available. I began to wonder if this fabulous program could possibly be set up to autosave to buffer or to disk unattended. Nowhere in the 850 Express! docs was there any mention of this so you can imagine my excitement and happiness to discover that 850 Express! could indeed download and save while no one was around! And...wow, is it easy to do! Here is how: ==>Boot up your 850 Express! modem program (I use version 3.0--I don't know if earlier versions will support this) and turn on your modem. From the main menu hit <ESCAPE> (which forces the program to think you're on line) and then press OPTION (which saves anything that comes in to buffer. Set up this way, as soon as a call comes in, the modem will autoanswer and save to buffer any incoming text. To check to see if any file has come in, simply turn on your monitor (I also hit the <SPACE> bar at this point to prompt the computer out of the attract mode--i.e. changing colors, etc.). If text is on the screen, hit <START> to go the menu and save the buffer to floppy. This will clear the buffer so now just view that file from the floppy or read your mail from a word processor. This has been tested on the Supra 1200AT, Avatex 1200 and Avatex 1200hc and should work the same on most Hayes compatible modems. To test your modem to see if it will indeed work in this fashion, turn your computer and modem off, turn your disk drive off and your computer back on so only the READY prompt of BASIC is showing. Turn your modem back on as if you were going to use it. Now have someone call your number. If your modem answers the phone without having a program to tell it to do so, then it will work perfectly as described. If, however, your phone rings and your modem does not respond, you may have to command it to auto answer in this way: ==>From the main 850 Express! menu, choose ASCII (not ATASCII) translation. Now hit <ESCAPE> and with your modem turned on and ready to receive data, type ATAA. Then hit <RETURN>. (This in all Hayes compatible modems commands the modem to autoanswer.) Now, hit <OPTION> to save any incoming info to buffer and you're all set. [GLAD Editor's note: Most "standard" modems have a switch or permanent internal command setting to place the modem into auto-answer mode on powerup, but the ATAA is fine if done every time you want it.] Remember, in this configuration you are saving to buffer so the size of your buffer depends on the DOS you are using. Here are my experiences: ATARI DOS 2.0, 2.5 gives you 3328 bytes SpartaDOS 3.2 gives a buffer of 4608 bytes SpartaDOS 2.3 gives the largest buffer of 8064 bytes, big enough for most all your letter capturing needs. For those of you who expect great volumes of incoming text, you'll want to save direct to RAMdisk or floppy disk. In order to do this with Express!, you must fool the program into thinking it is on line while you set this up. Here is how you do this: ==>Most Hayes Compatible modems have dip switches. On the Avatex and Supra modems you would push switch #7 down. This is the CD (forced carrier detected) switch. On the above mentioned modems, the down position is the "on" position. With the CD switch activated, the Express! program thinks it is on line. It seems to do no harm to leave this switch on while waiting for a file to come in. Just be sure you return the switch to the off position before making your next call or you'll get a false "connected" indication. Keep in mind that this switch need NOT be turned on when auto saving to the BUFFER only in Express!. So, to auto save to disk, turn on your CD dip switch, hit <ESCAPE> from the main menu to force terminal mode, hit <START> to re-enter main menu, type "T" to capture to disk. You'll be asked to give it a file name and as soon as you do and hit <RETURN>, you'll be all set to save to disk. Do not hit <OPTION> to auto save to disk, autosave is already turned on by choosing the "T" function. Plus, you can always tell if autosave is on just by looking at the border color of your screen. Things to keep in mind: 1) Whenever you are sending directly to another computer, you MUST use HALF DUPLEX. Use full duplex only when communicating with a BBS. If you are setting up to auto receive, it is preferable to be in half duplex but it is ABSOLUTELY necessary for the sending modem to be in HALF DUPLEX. 2) It is probably best to use the standard ASCII translation unless you know for sure that only ATARI computers will be sending you files. In that case use ATASCII. No harm will come, however, if someone sends a text file to you in ASCII and you are receiving in ATASCII, as long as it is just text. You could not send inverse characters and CONTROL characters unless both sending and receiving terminals were in ATASCII. 3) If you don't have a copy of 850 Express! version 3.0, ask your SysOp to post it for you. If he doesn't have it, contact me and I'll get it to you. 4) I only know for sure that this method of auto saving works with 850 Express! version 3.0. I know it does NOT work with MPP Express! version 1.0. I haven't tried it with 1030 Express! although I feel it probably would not work since the 1030 does not come with a ring detector. [GLAD Editor's note: Other software would allow the use of an XM301, as it DOES have an answer mode.] 5) I truly recommend SpartaDOS 2.3 because of the large buffer it gives and it will read and write to most any other DOS. I sincerely hope I didn't make this sound difficult to set up...it's not. In MOST cases you simply turn on your modem, boot the program, Hit <ESCAPE> and then hit <OPTION>. And that's all! If you have any questions, comments, or just want to try it out, you can call my autosaving 850 Express! at 813-393-0173, between the hours of 1:00am and 8:30am, 300 baud HALF DUPLEX, ATASCII (ASCII will work fine if you don't have ATASCII). I auto receive at 300 baud because not all my family members have 1200 baud yet...but I have a feeling that it won't be long!!! Remember also that when you call another modem set up to autosave, you receive no prompts when the modem answers the phone. As soon as the connection is made, you are "live" with the other computer. You may then type your message or send a pre-typed file from disk. DO NOT SEND XMODEM to me since I do not set up my program to receive that way. I sincerely hope you receive some enjoyment out of this information. | Rovac Industries, Incorporated | | P.O. Box 74, Middlesex, NJ 08846 | | (201) 968-8148 | |Copyright 1989 All Rights Reserved| CompuServe: 71777,2140 GEnie: ZMAGAZINE Source: BDG793 ZMagazine Headquarters BBSes: Centurian BBS--(314)621-5046 (618)451-0165 Chaos BBS--(517)371-1106 Shadow Haven--(916)962-2566 Stairway to Heaven--(216)784-0574 The Pub--(716)826-5733
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