Cautions When Replacing Disks - Epson TF-20 Reference Manual

(2) SYSGEN
This command is one of the two methods available for creating new
system disks. Since SYSGEN copies only the system area and files whose
file type is ".SYS", it does not affect any of the other files on the disk and
can be used to convert a non-system disk which you are already using into
a system disk.
To create a new system disk, place the current system disk in drive A and
the disk which you wish to make into the new system disk in drive B. As
with the FRMAT command, the HX-20 will ask for confirmation before
executing SYSGEN.
For disks that were used as system disks in another system, you must first
execute.a FRMAT command before executing SYSGEN. If the disk set in
drive B is different from the disk previously set in drive B, you must
execute a RESET command before you can execute SYSGEN. See 3.4
Cautions when Replacing Disks and 4.4 Commands and Statements for
details.
(3) COPY
This is a utility program that can be used to copy files or whole disks. By
copying whole disks, it can be used to create new system disks. The entire
contents of the disk set in drive A can be copied to the disk in drive B (or
similarly, from C to D if two TF-20 disk units are being used). The copy
utility can also be used to copy single files as selected by the user. See 4.6
Copy Utility, for details.

3.4 Cautions when Replacing Disks

Before changing the disks set in the disk drive, it is imperative that you first
execute a CLOSE statement. If the CLOSE statement is not executed, the
data in the buffer will not be written as intended to the current disk and
may be accidentally written to the next disk inserted in the drive.
Disk BASIC protects disks against this kind of accident by write protecting
all newly inserted disks. If an attempt is made to write data to a disk that
has been write-protected, a "Disk write protected" error will occur.
3-4
The function of t h e RESET command is to cancel this protection and
prepare the disk drive for a new disk. However, it should be noted that the
RESET command initializes the disk system and that the contents of any
disk open at the time of its execution will be lost. See 4.4 Commands and
Statements.
There are also dangers associated with rebooting Disk BASIC after you
have left Disk BASIC by such means as turning OFF the power switch of
the HX-20 or pressing the MENU
processing.
Rebooting Disk BASIC without turning the power of the TF-20 OFF or
when an operation in the TF-20 has been halted results in the same
conditions as when files have been left open. Therefore, inserting a disk at
such a time poses a similar risk of the data on the disk being destroyed. It
is a good idea to execute a RESET command after rebooting Disk BASIC
under the above mentioned conditions.
key in the middle of program