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GENERAL SYSTEM
OPERATION
2.7 -- Diskette File Concepts
2.7.3 File deletion
Unlike
file
creation,
file
deletion
is
controlled
explicitly by the operator
via
the
DEL
command
which
is
described
later.
No
other
command
program
will
delete
existing files on
the
diskette.
Exceptions
to
this
are
commands
that automatically
cr~ate
an intermediate work file
to perform the command's function.
These intermediate
files
are deleted by the command as an automatic clean-up process.
2.7.4 File protection
All MDOS files can be configured with delete protection,
with
write
protection:
or
with
no
protection.
Delete
protection
will
prevent
the
operator
from
inaoverten~lY
deleti~g
the file (the
protection
can
be
changed
by
the
ope rat
0
r
sot hat the f
i
1
e can bed e
1
e ted ) .
Wr i t e pro t e c t ion
will prevent any command from writing to that file as well as
preventing
deletion
of
the
file.
Normally,
files
are
unprotected, alloUJing both writing
to
or
deletion
of
the
file.
The
NAME
command,
described later»
can be used to set
or to change a file's protection.
2.8 Typical Command Usage Examples
The following
sections
give
simple,
but
meaningful,
descriptions
and
examples
of the most frequently used
MDOS
commands in a typical software development
environment.
No
attempt
is
made in these sections to cover all capabilities
and options of the described commands.
The detailed
command
descriptions
in
PART
II
serve that purpose.
After reading
this section,
the operator should
be
able
to
go
"on-line"
with
MDOS
and be able to display the directory of
a
diskette,
create a source program file,
assemble it, and load
it
into
memory for testing.
The commands to delete a file,
to change
its name or protection,
to copy it between
diskettes
or
to
tape
are
also
described.
New MDOS
diskette generation is
discussed in the last part of this section.
It is assumed in
the
subsequent
discussion
that
the
system
has been properly installed and initialized.
Thus,
a
system diskette with the MDOS commands resides in drive zero.
Command program files have a suffix of
"eM"
which
is
supplied
as a default to the first file name that is
entered
on
the
command
line.
The
default
logical
unit
number
that is
supplied is n:o",
In
the command examples
that
follow,
it
will be seen that both suffix and logical unit number are not
specified for the command name.
of
The following notation will be used in
the
description
the
command
line
formats
as
well
as
throughout the
Page
02-15
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