Radio Shack TRS-80 model III Owner's Manual page 49

mjTRS-80
MODEL
III
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:
FILES
PEC?. 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
Q
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
O
Previous
page
To change
the
file
contents, press
®.
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 (ENTER)
,
press
(BREAK)
.
This
will
put
you
back
in
the file-display
mode
without updating
the diskette
file.
You may
press
CD
then
Q
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
(BREAK) again
and you
will
be
returned
to
trsdos
ready.
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