| ROVAC ZMAGAZINE | | Issue #168 | | August 1, 1989 | |Copyright 1989, RII| |This week in ZMagazine| * Analog Computing Table of Contents * *** ST*ZMag Education Focus *** D.A. Brumleve *** Hard Drive: Toy or Necessity *** Geo Frazer *** Weatherman's Wisdom *** *** Z*NET Newswire 8-bit Edition *** Harold Brewer |ANALOG COMPUTING TABLE OF CONTENTS| ANALOG COMPUTING #76, September '89 FEATURES Macro Editor..............Frank Seipel Type complete lines with a single keystroke. This program will also create an AUTORUN.SYS file that'll install your macros at every boot-up. Sharp Shooter....Matthew J.W. Ratcliff More light-gun fun from the author of last month's light-gun tutorial, -Gun Assist.- Recursion................Gregg Hesling It has been claimed that Atari BASIC, because of its inability to pass parameters into subroutines, is not capable of recursion. Guess again. RAM Disk 800XL..........Jerry van Dijk Now 800XL owners can use some hidden memory to set up a RAM disk. Skeet Shoot...............Tracy Jacobs Ready? Pull! Use your joystick to blast clay pigeons out of the sky in this all-machine-language simulation. XF551 Commands..........Jerry van Dijk An exploration of the undocumented commands for controlling the new XF551 disk drive. REVIEWS The Chessmaster 2000 .................Matthew J.W. Ratcliff Diamond GOS ....................James F. Patterson Crossbow .................Matthew J.W. Ratcliff Crime Buster .................Matthew J.W. Ratcliff COLUMNS Boot Camp...................Tom Hudson BASIC Training..........Clayton Walnum ST Notes...................Frank Cohen The End User........Arthur Leyenberger DEPARTMENTS Editorial...............Clayton Walnum Reader Comment 8-bit News Disk Contents M/L Editor..............Clayton Walnum BASIC Editor II.........Clayton Walnum |ST*ZMAG EDUCATION FOCUS| |by D.A. Brumleve| Reprinted from ST-ZMagazine #31 An extract from Parent Page offered at the WOA Seminar on Kids and Computers Copyright 1989 by D.A. Brumleve Used by STZMagazine and/or ZNet by permission WHERE'S MY DISK? Adults use various cataloging systems to help them find the disk they want. A typical store-bought disk box has partitions which the adult user will label according to the type of program filed in that location. The labels on the disks themselves can also be a big help. There are a myriad of labeling programs to choose from. Store-bought labels encourage the use of color in separating disks into categories, and this can also aid at-a-glance identification. Effective labelling can also help your pre-schooler identify and select programs from his or her disk box. Colored labels, colored disks, and, above all, pictures on the labels can all be helpful in allowing the pre-schooler to find the disk he or she is looking for. A picture of piano keys identifies the child's on-screen piano program. A picture of a barn tells the child that this disk holds his favorite matching game Barnyard. The simplest way to provide picture labels of this kind is, of course, to draw them with a marker. At least one of the adult-oriented labeling programs, STICKER (Shareware for the ST), allows the display of computer-printed pictures. Another alternative for computer printing is complicated, but the results can be very handsome, durable, and useful. The director of a local preschool, Creative Discovery School, had asked for picture labels with large-type titles and arrows indicating the proper position of the disk when inserting it into the drive. I used a paint program to draw the pictures, then loaded them into a desktop publishing program to add the title and arrow. The result was printed out on an 8 1/2- X 11- sheet (with several labels to a page), and then I took the sheet to a copy shop where it was duplicated onto sticker-backed paper. The labels were cut out and mounted on the disks. While the ink from labels printed on a printer sometimes smears, copier -ink- normally does not, so the resulting labels are very hardy, even in the hands of children. |HARD DRIVE: TOY OR NECESSITY| |by Geo Frazer| Reprinted from The Atarian Knoxville Atari Users Group ONCE YOU HAVE TRIED ONE, YOU WILL NEVER WANT TO GIVE IT UP AND THAT IS THE ONLY PROBLEM WITH HARD DISK DRIVES: they are psychologically addictive. A hard drive will move your computer into a whole new class of productivity. Whether you use it for word processing, telecommunications, or a database, it will double your efficiency. Once you own a computer, you have nothing without an output device, so you purchase a printer and now you think you are in business. Then you find that some programs require a second drive. What now, are there any alternatives? Well, there is a good one if you have the memory. It's called RAM and works great until you turn off your machine. Another choice is a second floppy, but of course you're limited to 760K or less and it's slow. What about a hard drive? Let's talk about it and maybe we can learn a thing or two. Maybe we should start with a comparison of the data transfer rate. 1050 DISK DRIVE .9K bytes/sec. 1050 w/ultra speed 2.5K bytes/sec. ST RAM Disk 200K bytes/sec. SF354/314 DISK DRIVE 4K bytes/sec. These estimates are actual--not burst rate. All drives will actually read much faster, but a hard drive can read 30K bytes/sec, and we must subtract the head movement time. So, it can be seen that the hard drive is 7 1/2 times faster than the 3 1/2 drive and 33 times faster then the 1050 drives. This gives a significant increase but it isn't the reason most people buy a hard drive--it's the capacity that is the deciding factor. A hard drive can be anywhere from 10Mb to 230Mb for the home drive. It is more reliable than a floppy, is quicker than a floppy, and has the capacity to store more than one disk at a time. A hard drive can be made to look like many drives by partitioning it into large sections of (for example) 15Mb each. How do they work? I thought you would never ask. GREAT! Well, so much for the technical data. Lets move on. First of all the normal drives spin at around 288 to 300 rpm, while the hard drive winds at a 3600 rpm. Second, the floppies have only one platter spinning while the hard drive may carry four or six platters, reading and writing on both top and bottom with one or more heads on each side of the platter, riding on a cushion of air several microns above the surface. The platters are divided up into concentric circles called cylinders, (tracks on floppies) from 150 to 640 per platter (40 on the 1050 and 80 on the ST drives). As you may have guessed, precision head stepping is required and the drive is sealed to keep out dust and grime. At present there are two density schemes is use that are common, MFM (modified frequency modulation) for us tech types--bit packing for the rest of you. It is the standard for the 1050, XF551, and ST drives. The main difference is the 8-bit drives use 128K sectors and the ST drives use 512L sectors. MFM has been around for a few years and is very reliable, but recently a newer packing scheme called RLL (run length limited) has been introduced and is catching on well because it packs 1.5 times the data as MFM in the same amount of space. A better type of media must be used on the platters and some timing changes, but everything else is the same machine. If these hard drives are capable of 5Mb/sec, how come they slow to thirty Kbits? Because of the computer architecture, the operating system, the sector skew, and the DOS all combine to slow down the actual rate of data transfer. How come the Atari hard drives cost so much? In the magazines they are offered for the IBMs for 200 to 400 dollars. Well, what they expect you to know is that the IBMs need boards for everything and that goes for the hard drives too. They didn't give you a price of the whole animal. The hard drive needs to have an interface to the drive (a host adapter), like on the 8-bit computers to printers, then it needs a controller board. This is a high speed intelligent device that has it's own CPU, ROM, RAM, and interface circuitry. It has an instruction set which interprets the commands from computer to the drives positioning the heads. Supra is installing a 20Mb in the Mega machines, but I don't recommend it due to the fact they are using the Mega's power supply and I feel that it wasn't designed for the load. Most hard drives are designed to last for 5 years continuously operating without a breakdown and most will. It is recommended to leave it on continuously as the shock and torque of starting does more damage than running all the time, but due to lighting I don't recommend it. The biggest problem with hard drives is bumping them while they are running. Remember how close I said the head rides over the platter? If it touches, it damages the platter and the head. The hard drive is the next thing after a printer to make your system real. It will give you good reliable service and if you make a back-up, in case a crash does occur, you won't loose too much time. If you are a PURE GAMER, then you will find yourself limited with a hard drive, but if not, then like me you will quickly become hooked and wonder how you ever got anything done before hard drives. If you have an interest in a hard drive, contact me and we will get the best deal we can. |WEATHERMAN'S WISDOM| September 1989 SEVERE THUNDERSTORM FACTS Most thunderstorm related deaths are not from severe weather or tornadoes. Lightning is the number one weather killer during the warm summer months. On the average, lightning will kill about 125 Americans a year. Even if severe weather isn't expected, follow these precautions when thunderstorms are on the way: 1. Get inside! When a thunderstorm approaches, it is safer to be inside a home, large building, or auto. 2. If outdoors, do not stand near a tall isolated tree, or the tallest tree in a group 3. Get out and stay away from water! Thunderstorm winds can capsize small boats. Sailboats can act as lightning rods. 4. If your hair stands on end then lightning is about to strike you! Immediately drop to your knees and bend forward with your hands on your knees. 5. If someone is struck by lightning, they can usually be revived by quick CPR administration. 6. People in mobile homes should move to a designated shelter area. 7. Objects should be tied down if they could be blown around by high winds. It's best to bring lawn chairs, trash cans, toys, etc. inside. KY IN Tornadoes per year 8 23 Peak months April April-May Severe storms/year 75 200 Watches/Warnings Explained The first step in the process is a -watch-. A -watch- covers a large area, usually 30,000 to 50,000 square miles. Severe weather is possible in the watch area. It does not mean that it will happen, only that it could. You should -watch- for storms moving into your area. There are two types of watches: SEVERE THUNDERSTORM WATCH--means a possibility of large hail (3/4- or greater) and damaging winds (58 MPH or more). TORNADO WATCH--alerts us to the possibility of severe thunderstorms and tornadoes. A -warning- means there is an actual report of severe weather or that radar suggests the strong possibility of severe weather. A -warning- covers a far smaller area than a watch. Most warnings are for a one or two county area covering the location and path of a severe storm. Next month: Lightning--Super killer |Z*NET NEWSWIRE 8-BIT EDITION| |by Harold Brewer| From ST-ZMagazine #30 and #31 come these insights by Ron Kovacs' Editor's Desk and Z*NET Newswire: -...User Group officers and members please take note of the request from Atari Corp. They need your help in getting the official User Group list completed. -If you are not registered, or even think you're not included, please send your group's name and contact address/phone number to Chris Roberts. Also included in this request, please get a post office box registered in your group's name. The importance of the request cannot be ignored. Atari cannot forward your information to future members without a PO BOX. Current registered User Groups with Post Office Boxes are scheduled to receive a press package direct from Atari. You cannot afford to NOT be registered. Send a post card to: Chris Roberts Atari Corporation 1196 Borregas Avenue Sunnyvale California, 94086... -...Total Control Systems seems to be unavailable. Calls made to his number don't even receive his answering machine anymore, and NEVER a call returned. I have personally read in a few newsletters the same story over and over. We at ZMAG have made attempts since January 1989 to contact David Sullivan without any success. Many 8-bit users have sent David money for his GOE cartridge, and have not been updated in any way with it's progress. -The GOE cartridge is a Graphics Operating Environment for the 8-bit Atari computer. It is similar to STjr, already released and produced by Alan Reeve of Reeve Software. As a former 8-bit Atari owner, and with the present atmosphere surrounding the 8-bit, I feel David Sullivan should surface and repay or release his product now... -...Interesting news from Atari is expected next week. Stay tuned for more details. Later in the month, (August), Atari is expected to make an announcement on the 25th. This was confirmed with Chris Roberts earlier this week. -Please make a note of our NEW address. Formerly located at Post Office Box 74, we move to Post Office Box 59 effective with this issue. The following message was left to me on the National ZMagazine BBS (Centurion) by Bob Klaas, the owner of K-P Products (selling the K-P interface--formerly the Supra hard drive interface): -From what former Supra Interface owners tell me, Supra Corporation has been referring all problems to me which concern the 8-bit interface they sold prior to my purchasing the rights. -I will continue to support all owners of the interface Supra sold with upgrades as they become available and assistance with any problems they may have. I have set up a message base on my BBS (The Repair Shop BBS at 801-967-8738--300-19.2bps Hayes) also. The old text files that Supra put out with the interface have been converted to disk file and are available for download to those owners who have bought the interface through second parties and have lost the documentation. -Since aquiring the interface rights from Supra I have had requests for complete hard disk systems. It was not my intention to get into assyembling hard disk systems but there are those that are uncomfortable putting one together, so I have come up with a complete package for the 8-bit user. Interface and a 20Mg hard disk drive system completely formatted out and ready-to-run for $503.00 shipped COD. This is for either the 800XL or the 130XE. The drive will be formatted with MYDOS as that is what I got with the rights from Supra, but can be converted to SpartaDOS by the purchaser with no effort using XINIT and HDINIT after they receive the drive. -Thank you for letting the Atari 8-bit community know the interface is available again. I will do what I can to keep the price low and the interface will remain available indefinately as I can keep it going by selling just 1 as well as 100. The Pub BBS is no longer a regional ZMagazine Bulletin Board. We thank the SysOp and users of The Pub for their interest in ZMagazine. | Rovac Industries, Incorporated | | P.O. Box 59, Middlesex, NJ 08846 | | (201) 968-8148 | |Copyright 1989 All Rights Reserved| Reprint permission is granted providing ZMagazine and the original author is credited. CompuServe: 71777,2140 GEnie: ZMAGAZINE Source: BDG793 ZMagazine Headquarters BBSes: Centurion BBS--(618)451-0165 Chaos BBS--(517)371-1106 Shadow Haven--(916)962-2566 Stairway to Heaven--(216)784-0574