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Syndicate ZMagazine Issue 168
| 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|
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