## Making a Backup of the System Disk

Before getting too much more involved in further experimentation, NOW is the time to make one or more exact copies of your System Disk in case some misfortune befalls your one and only master System Disk. Making a backup involves two steps: formatting a blank disk and running a backup program.

### Formatting Blank Disks

Before the actual backup procedure can be done (or any fresh diskette is used for any purpose), the blank disk which is to become the backup disk must be initialized by OS-9's format command.

IF YOU HAVE ONLY ONE DISK DRIVE you have to be extra careful not to accidentally FORMAT your system disk. Type:

    format /d0

and when you see the message

    COLOR COMPUTER FORMATTER
    Formatting drive /d0
    y (yes) or n (no)
    Ready?

immediately remove your system disk and insert a blank disk before you type Y. IF YOU HAVE TWO DISK DRIVES place the blank disk in drive one and type:

    format /d1

WHEN THE BLANK DISK IS IN THE RIGHT PLACE, type Y, then ENTER. This initiates the formatting process. IF THE CORRECT DEVICE NAME (/D1) IS NOT DISPLAYED: TYPE N RIGHT NOW and start over, OR YOU MAY ERASE your System Disk.

When you are asked for a disk name, type any letter, then ENTER. The name you give is not important. If you have only one drive, replace the system disk after the format program has finished. If the format program reported any errors, try again. Disks used for backups can't have any errors. You're now ready to run the backup program.

It takes several minutes for the format program to run. During its second phase the hexadecimal number of each track will be displayed as it is checked for bad sectors. If any are found an error message for each bad sector is given.

### Running the Backup Program

The backup program makes an exact duplicate of a disk. It can be used even if you only have one disk drive.

IF YOU HAVE ONE DRIVE type

    backup /d0 #32k

The backup program will prompt you to alternately insert the source disk (the system disk) and the destination disk (the freshly formatted disk).

IF YOU HAVE TWO DRIVES type

    backup #32K

The backup program will respond with

    Ready to backup from /d0 to /d1?

Now enter Y for yes. It will then ask:

    X is being scratched
    Ok ?:

Answer Y for yes again, and the backup process should begin.

The backup command has two phases: the first phase copies everything from drive zero to drive one checking for errors while reading from the master but not for “write” errors. The second phase is the “verify” pass which makes sure everything was copied onto the new disk correctly. If any errors are reported during the first (copy) pass, there is a problem with the master disk or its drive. If errors occur during the second (verify) pass, there is a problem with the new disk and the backup program should be run again. If backup repeatedly fails on the second pass, reformat the disk and try to backup again. If backup fails again, the disk is physically defective.

After you have made your backup disk, try turning the computer off and restarting the system with the copy you just made. If it works OK, store it in a safe place in case it is needed later. You should always have a backup copy of your system disk and all other important disks.