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SPACE - Library 1 - Volume 1.iso
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1988-03-30
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COPYRIGHT NOTICE
Magic Shadow Archiver hereafter referred to as MSA is Copyright
(C) 1987 by Steve Feinstein. MSA is distributed under the User
Supported software or 'Shareware' concept. If you find this program
useful and decide to keep and use it please compensate the author for
his efforts and register by sending a check or money order for the sum
of $10.00 to:
Steve Feinstein
56-26 244 Street
Douglaston, New York
11362
MSA may be copied and distributed freely provided it is not
modified and this documentation is included along with the two program
files.
MSA may not be included with any other product for any reason
whatsoever without the written permission of the author.
No charge may be levied for a disk containing MSA except for a
disk handling charge of up to $8.00.
With all the various emulations that are being implemented on the
ST the need for a means of transferring or storing data contained on
disks of the various system formats, easily, from TOS has become a
necessity. MSA is an attempt to satisfy this need.
Though all precautions have been taken to insure that MSA will
function properly the author cannot accept any responsibility for any
damages that may result from it's use or missuse.
Please report any bugs and/or suggestions by dropping a note to the
above address.
T h e M a g i c S h a d o w A r c h i v e r
MSA creates an image file of any unprotected disk that contains
512 byte sectors and writes it to a standard ST file using a simple
track compression algorithm. This includes disks written under:
Atari ST/TOS
Magic Sac
IBM/MS-DOS
CP/M
This means you can store or backup and then re-create any
unprotected disk of various operating systems directly from the ST
desktop. For instance bulletin boards can now easily handle files of
entire Public Domain, Share Ware or Demo program disks in Magic Sac,
IBM, TOS and other formats which can be Up/Downloaded and then restored
to their original form ready to use with all boot sectors, roots and
subdirectories intact.
Using MSA
STORING A DISK - To create an MSA archive file just boot MSA.PRG and
after the functions panel appears place the disk you want to archive
into the source drive A or B (this may be set using the buttons in the
'Drive' box at lower right off the panel - the default is drive A). To
enter a name for your MSA archive file and set the destination
drive/partition click on the long rectangular box at the bottom of the
main panel and a standard GEM directory box will appear. Click on OK
when you are finished making your entries. The name FILENAME.MSA will
be used if you neglect to enter your own filename.
At this point you can click on the 'Do it!' button and MSA will
start off by checking the source disk's format and display how many
sides, tracks and sectors per track in the 'Information' area. MSA
will then continue by reading each track of the source disk writing to
the destination drive/file as it goes. To the right of 'Information'
area you will see four fields that display the track being
read/written, the side, the status of the operation (will show error
codes if they occur) and the compression effectiveness for each track.
When the archiving operation is finished you will be presented
with a box showing the size of the original disk, the size of the MSA
file and the total compression acheived. This file now contains an
image of your disk including the format information that will be used
by the 'AUTO-FORMAT' function to re-create it.
Re-creating A Disk From an MSA File
To re-create a disk from a stored MSA file place a blank disk into
the destination drive (set A or B by using the 'Drive' box at the lower
right of the main panel) and click on the 'DISK -> FILE' button at the
lower left of the panel. This will change the button's markings to
'FILE -> DISK' and the 'AUTO-FORMAT' button to the right will become
enabled. Enter the name of your stored MSA file and source drive that
you will be restoring from by clicking on the filename box at the
bottom of the panel. Now click on 'Do it!'. MSA will format and
create a new disk which should be an exact image of the original.
Features
There are a number of user selectable or editable options that you
will find useful when using MSA.
ANALYZE - The 'Analyze' button allows you to check the format of a
source disk before actually creating an MSA archival file. Place your
source disk in the selected drive (A or B) and click on 'Analyze'.
The number of sides, number of tracks and sectors per track will be
displayed in the 'Information' area.
MSA uses this function automatically (unless the 'Override' button is
set) when creating an archive file. The 'ANALYZE' feature works on
most standard formats used in the above operating systems. MSA will
'Automatically' copy and restore disks within these format ranges:
Single/Double sided
80 tracks or more per side
8 or more sectors per track (512 bytes per sector)
(11 [or more] sector destination disks must be
pre-formatted.)
Since the operating speed of MSA was of major concern the analysis
was kept within these ranges. (Forty track IBM disks may be set using
the 'Override' button.) Because MSA is intended to work on different
system disks the format analysis is made of the physical track/sector
format of the disk and not through the system format data on the disk.
Disks that have been formatted and reformatted with various capacities
or systems can fool MSA into doing the wrong thing. Usually you will
end up with an unecessarily large file but care must be taken to insure
that these messy disks are stored properly by using the 'Override'
feature and entering the format parameters manually.
Compression
At this time MSA uses a rather rudimentary data compression
algorythm. It simply checks for strings of contiguous bytes of similar
value and stores them in short encripted form.
Disks containing many empty sectors or repeated bytes (such as
graphics files) will result in the smallest files. You can further
compress your MSA files by using other compression programs such as
arc.ttp, arca.ttp, etc. Note: smaller systems may not be able to arc
the larger files created by MSA as with double sided disk files. These
disks may be stored in segments or sections. i.e. tracks 0-39 as
FILE_A.MSA and 40-79 as FILE_B.MSA on a DS/80 track disk.
Segmenting A Disk Image
To break a disk down into multiple MSA files click on and 'select'
the 'Override' button before you start the archival operation. Then set
the starting and ending tracks by clicking on the 'Tracks:' field.
Change the starting and ending tracks to your needs and after placing
the source disk in the drive proceed normally by clicking on the 'Do
it!' button. Remember to use descriptive names for each section of the
disk saved (for your own reference). MSA handles all the rest. MSA's
'Auto-Format' feature will restore each section to it's proper position
on the disk when recreating the disk. Sequence is not important.
The Manual Override Button
The auto-analyze feature can be toggled off by clicking on the
'Override' button. This will deselect this feature. This is useful
when storing disks that have previously been formatted as double sided
but now contain single sided information. i.e. A disk that was used as
a double sided TOS disk and then used as single sided Magic Sac disk
containing ported Mac program files.
If MSA finds a second side on a single sided format it WILL copy
it so use the 'Override' to set MSA for 1 side if that is all you want
stored. An easy way to check is to use the 'Analyze' feature alone
before you start actually storing the disk. This will tell you if MSA
thinks there is a second side.
Aborting An Operation
Pressing and holding down either mouse button will abort a store
or restore operation if you need to do so. When the disk is being
checked with the 'Analyze' feature you must wait for it's completion
before you can abort.
IBM or MS-DOS disks
MS-DOS or IBM program disks are usually double sided but often use
only forty tracks (0-39). You can save time as well as avoid an
oversized MSA file by manually setting MSA for 40 tracks. I'm sure
that many PC-Ditto disks have previously lead lives as ST TOS disks.
Standard format for IBM or MS-DOS (v3.x) disks:
Tracks 40
Sides 2
Sectors 9
DOS system disks
IBM DOS system disks can be copied and restored with the system
boot sectors and DOS version formats intact and ready to run. MSA may
also be used with 5.25" drives.
Magic Sac disks
Magic Sac disk format is as follows:
Tracks 80
Sectors 10
Sides 1 or 2
One of MSA's most useful applications is the transferring of Magic
Sac disks.
We feel that the Magic Shadow Archiver will quickly find a place
in your utilities box as you discover more ways using it. Please feel
free to drop us a note regarding any problems as well as suggestions
for improvements.
Bill Kokoni