Radio Shack TRS-80 Owner's Manual page 58

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MS-80
MODEL
111
DISK
SYSTEM
F
(File
Patch
Utility)
This
command
lets
you
load
and modify
the contents of a
diskette
file.
When
you
press
©, debug
will
respond with
the prompt:
FILESPEC?.
Enter
the
name
of
the
file
to
be
patched.
debug
will set
up
a full-screen display
showing
the
first
256
bytes
in
the
file.
You
can
"page"
through
the
file
using
the
CD
and (ED
keys.
Figure 10
gives
a
typical display.
In
this
file-display
mode,
both hexadecimal and
ascii are
given
for each
byte,
if
a
code
has
no
displayable
character, a
period
is
shown
in the ascii area.
The
display control
commands
are like those for the
normal
file-display
mode:
CD Next page
(—)
Previous page
To change
the
file
contents, press
fl).
This
puts
you
in a
modify-memory mode
like
the
one
previously described.
Use
the
arrow keys
to position the cursor
(a
blinking character), then type
in
the correct contents
as
a
hexadecimal
value.
When
you
are
through changing
a
page on
the display, press (ENTER)
.
The
diskette
file
will
be updated and you
will be returned
to the file-display
mode.
To
cancel
changes made, do
not press
CENTER)
,
press
(BREAK)
.
This
will put
you
back
in the file-display
mode
without updating
the diskette
file.
You may
press
CD
then
CD
to
restore the
page
display
to
its
actual contents.
To
quit
patching
a
file,
press
(BREAK)
while
in
the
file
display
mode, debug
will
prompt you
for a
new
file
specification. Press
(
BREM)
again
and you
will
be
returned
to
trsdos
ready.
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