Backup Magic SDC
                                     Copyright © 2006, 2023
                                             By
                                         Carl England

    Backup Magic was originally developed in 2006.  Its purpose was to give software owners the 
capability to back up their copy-protected program disks.  Disks age.  Software companies no longer 
support their older software packages.  Some software companies have ceased to exist.

    The original Backup Magic software was designed to make backups from one physical floppy disk 
to another physical floppy disk.  (There was also limited support for moving the floppy image to
virtual disks.)

    Technology marches forward.  Floppy drives are becoming scarce.  But we don’t want to lose our 
old software forever.  So I have developed a newer version of Backup Magic that works with the CoCo 
SDC.

    The actual heart of the new version, the machine language routines have not been modified from 
the original version (with the exception of adding a new copyright date.)  The BASIC routine had to 
be modified to allow the disk image to be written directly to virtual disks.

    While the original BASIC program only reported the progress as each track was being copied, 
this version gives detailed information about the tracks giving you an insight into how the disk 
was copy-protected.


                                        Running the Program 

Prerequisites:

Color Computer 3
Multipak Interface
CoCo SDC in Slot 4
Disk BASIC 1.1 (2.1) Cartridge in Slot 3
Floppy Drive 0

Preparing for Operation:

    Cover the write protect slot on your floppy disk.  You haven’t held onto that important 
software for 40 years to lose it now.  While every attempt has been made to ensure that Backup 
Magic will not destroy the data on your disk, it is possible that there might be certain instances 
when the software behaves in an unpredictable manner.  (Also, Backup Magic tests the disk and will 
not continue unless the disk is write-protected.)

    Either create an SDF virtual disk with a minimum of 40 tracks or use the included disk: 
BLANK41.DSK  (You can use your PC to copy BLANK41 and create as many blank images as you will need 
to copy your files)

    If using the provided disk image, you may rename it before or after the copy-protected floppy 
has been transferred.  If there are multiple disks in the software package, they should be named 
using the format: DISK1.DSK, DISK2.DSK, DISK3.DSK, etc.  (See documentation for the CoCo SDC.)


Copying a disk:

RUN"MAGICSDC

    Insert the physical disk to be copied in Drive 0.
    When prompted, enter the name of the destination virtual disk (There is no need to enter the 
extension as the default is .DSK.)

    Each track will be read and analyzed.  Backup Magic will attempt to recreate a virtual disk 
that is an exact image of the physical disk making no modifications to the input data. Some 
exceptions are necessary to create a working virtual image.

    Data that is read as A1 A1 A1 or 14 A1 A1  will be interpreted as FC FC FC.
If a sector F7 (decimal 247) is encountered, the sector number and size will be advanced one 
byte in the address table.


Sequence of operation:

    Backup Magic will read and analyze each track 

    Information about the track will be displayed.  Normally, the information will include:
        Track number, Disk side, Sector number, and Sector size

    Standard track numbers are 0 thru 39  (The minimum number of tracks is 34)
    Standard side is 0
    Standard sector numbers are 1 thru 18  (Normally includes all 18 sectors)
    Standard sector size is 1.  (0=128 bytes, 1=256 bytes, 2=512 bytes, 3=1024 bytes)

    Any track that does not conform to the "standard" has been copy-protected and cannot be 
copied using normal BASIC commands.  (Some track information will display RAW DATA.  These tracks 
have no sectors.  They may contain data or just be unformatted.  These will be written to the 
destination without being processed.

    Backup Magic formats a track using the information gleaned from the physical floppy.

    If the track contained RAW DATA, then Backup Magic proceeds to the next track.

    Backup Magic reads all sectors on the current track and checks for CRC errors.

    If CRC errors are encountered, then the sectors will not be written to the destination ensuring 
that the destination track will also contain errors.  (The sector data obtained from the Track Read 
is included in the formatted image and will have CRC errors.)

    ***NOTE*** CRC errors could also be caused by a dirty head or a damaged disk.  If all sectors 
on a track contain errors, that is most likely the result of intentional copy-protection.  If some 
sectors on the track have errors and others do not, then it is probable that the head needs to be 
cleaned or the disk is damaged.

    Backup Magic writes all sectors to the current track on the destination disk.

    Backup Magic loops until all 40 tracks have been copied.

    ***Note*** Use the latest revision of the CoCo SDC firmware.  Revision 121 and earlier does not 
support disks that contain sector number 247 ($F7).  Also, while Revision 121 will copy disks that 
contain CRC errors, it does not recognize the error and the copy-protected software may not 
function.

    ***Note*** If there are multiple disks in a series and some of the disks are not copy-protected,
they may either be copied to SDF images or “normal” DSK images.  The .DSK files use less storage 
space, but either format is acceptable for disks that are not copy-protected.  Copy-protected disks 
must be copied to SDF images.

    The original Backup Magic along with the original documentation can be found on the Color 
Computer Archive.  The email address is incorrect and questions about Backup Magic and Backup 
Magic SDC can be addressed to Gilbert.Nash@Gmail.com.