A
ll
and more about Sharp
PC
-1
500
at
http://www.PC-1500.info
Our
one·line program
is
complete. Change
to
the
RUN
mode and
wpe
:
This command instructs SHARP to
be<Jin
processing the statements (or, in this case, the statement)
in
our
program. Following orders, SHARP prints:
[ ,
_,oon
O( G
•••
on
the display. (Press ENTER
to
inform SHAR:P when you are through rcadin!J).
To
make
any
additions, changes
or
de
l
etions
to
ou
r program we must
return
to
the
PROgram
mode. If
our
program had contained an
error
and
had
not
completed successfully,
it
would
have been necessary
to
return
to
the
PROgram mode
to
correct
the
offending statement. Thus,
work
on
programs
is
accomplished in
the
PROgram mode, while
the
execution and testing
of
programs is performed in
the
RUN
mode.
C.
COMMANDS
VS.
STATEMENTS
You may have noticed
in
the
previous example
that
we
communicated
our
desires to SHARP
by
two
different
methotls. The instructions NEW
and
RUN
were performed immediately
afte
r we
prr.ssed ENTER. This type
of
instruction
is
known
as a command. The PRINT instructi
on
,
on
the
other hand. was somewhat different. It was entered in
the
PROgram mode, was preceeded
by
a number (
101.
and was
not
executed immediately, This type of instruction is known
as
a state·
ment.
In
some sense, the commands tell SHARP
what
to
do
with
the statements. For example, the
NEW
command
wil
I erase
all
currently saved statements.
It
is
important
to
remember that
comma
nds
may
not
be used within a program whereas statements almost
(but
not
quite) always
are
grouped to
form
a program.
D.
LINE NUMBERS
A BAS
IC
program consists
of
a series of numbered lines each containing one
or
more
state
·
ments.
The '"line numbers" are used
by
SHARP to maintain
the
correct sequence during
execution
but
do
not
become
pan
of
the
output
when
the
program
is
run. Statements may
be
entered in
any
order
but
are processed
by
the
computer sequentially
by
line number
(subi~t
to
modification,
as
we shall see later).
As a demon,stration. let's
add
a statement
to
our previous one·line program. Switch
to
the
PROgram
mode
and type:
Keystrokes:
mm
rn
moo
rn
1
••
," 1
~
c:orn
mm
crJ
lsr•Cfl
l
:;1
n
FTI
CJ
I
SH1nl
CJ
!••
<TER
I
27
Do
not sale this PDF
!!!
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