220
The next option in the menu is ‘Input value’. Choosing
this option will create an input screen. The statement
controlling this was:
INPUT N;"MY TITLE";"Please enter N..";"Do as you're told.";20:
Examine the snapshot on the right and notice
the connection between the various parts of
the
INPUT
statement and their effect. Note the
suggested value of 20, and note also that the
prompt of “Please enter N..” was too long to be
displayed. See the
PROMPT
command for an alternative that is simpler but
less flexible.
When you enter a number into the input screen and press
ENTER
, the next
line in
.MSG.IN
will display this value in a MSGBOX. When you then press
, the view number of 7 specified in the relevant line of
.MSG.SV
will
cause the
VIEWS
menu to be displayed again.
Notice that the input window is still displaying in the background. To stop this
happening, you could have included in
.MSG.IN
a line of
ERASE:
, which is
a command to erase the display screen. Try editing the program, inserting
this line before the MSGBOX line, and running it again.
The option of ‘Message 2’ displays the same
message as we saw before, but presented in a
different way. The
DISP
command divides the
display screen up into 7 lines (1 - 7) on which
you can display data.
For example, suppose memory A contained 3.56, then the command:
DISP 3;"The value of A is: "A:
would display the message
The value of A is: 3.56
on line 3 of the
display screen.
Notice also that this time when you press
ENTER
, you end up in the
HOME
view rather than in the
VIEWS
menu again. This is not an error. If you look
at the line in
.MSG.SV
controlling this option of the menu you will see that its
post execution view number was 0 (
HOME
) rather than 7 (
VIEWS
menu) like
most of the others. To see the
VIEWS
menu again, press
VIEWS
.