Tandy TRS-80 Owner Manual & Programming Manual page 63

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I I
SHUFFLING
DISK FILES
(Merging programs, using
many
buffers)
Because
storing
and
retrieving disk
files is
so
easy,
you
will
want
to
use
them
as
much
as
you
can. In
this
chapter, we're going
to
talk about
some
spe-
cial
ways you
can
use them.
MERGING
PROGRAM
FILES
With
the
first
method, you can
build a
program
out of related
program
"modules"
SAVEd
on
disk.
You can then
MERGE
any
of these
program
files
with whatever program you have
in
memory.
Type and
SAVE
these
two
related programs:
10
REM AGE CONVERSION
TO MONTHS
20
N
= N
* 12
30 A*
=
STR*(N)
+
"
MONTHS"
S A U E
"MONTHS/AGE",
A (ENTER)
10
REM AGE CONVERSION
TO
WEEKS
20
N
=
N *
52
30
A*
=
STRt(N)
+
"
WEEKS"
Be
sure
to
type the
A
when
you
SAVE
these
pro-
grams.
We'll
explain
why
later
. . .
Erase memory.
Now
put
this
program
in
memory:
5
INPUT "TYPE YOUR AGE"
i
N
40
PRINT "YOU HAVE LIVED"
A$
and combine
it
with one
of the
programs you
SAVEd.
Type:
SAVE "WEEKS/AGE",
A (ENTER)
MERGE "MONTHS/AGE"
(ENTERl
LIST
the
program
. . .
The Computer
has
MERGEd
"MONTHS/AGE"
with
the
program you have
in
memory.
Notice the
line
numbers
are the
same
as
they were
in
each individual program.
At
this point, this
is
the
program
you have
in
memory:
5
INPUT "TYPE YOUR AGE"
i
N
10
REM AGE CONVERSION
TO MONTHS
20
N = N *
12
53