Radio Shack TRS-80 Trsdos & Disk Basic Reference Manual page 174

Appendices
prompt
A
character or
message provided by
the
Computer
to indicate that
it's
ready
to
accept keyboard
input.
protected
file
A
disk
file
which
has
a
non-blank password, and
therefore
can only
be
accessed
by
reference to that password.
protection
level
The
degree of access granted
by
using the access password:
kill,
rename,
write, read, or execute.
random
access
memory
or
RAM
Semiconductor
memory
which
can be addressed
directly
and
either
read
from
or written
to.
"User
RAM"
is
that
portion of
RAM
which
is
left
untouched by
TRSDOS
and
DISK BASIC
code,
from hex 7000
to
end of
memory.
real-time clock
An
interrupt driven routine that keeps time
by
updating
certain
memory
locations every 25 milliseconds, regardless of
what
the
current
background
task
is.
At
power-on,
the real-time clock
is
set
to
00:00:00.
When
interrupts
are disabled,
the clock
is
stopped.
reset
To
press
the
reset
button on
the
rear
left
of the
TRS-80,
next
to
the
Expansion
Interface
connection.
Pressing
reset
is
equivalent to
powering up
the
Computer,
except
that
the contents of
user
RAM
are unaffected.
resident
system program
That
part of
TRSDOS
which
remains
in
RAM;
the "executive
TRSDOS
program", which
calls in
other
TRSDOS
code
as
needed.
read-only
memory
or
ROM
Pre-programmed semiconductor
memory
which
is
directly
addressable but can only be
read,
not
written
to.
The
LEVEL
II
TRS-80
includes
12K
of
ROM,
where
a
bootstrap program,
LEVEL
II
BASIC,
and other code
are
permanently
stored.
routine
A
sequence of
instructions to carry out
a certain
function;
typically,
a routine
may
be
called
from
multiple points
in a
program. For
example:
keyboard
scan routine.
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