Line 20 prints characters using the usual text coordinates. The VDU 5 in line

30 joins the text and graphics cursors. In line 50 MOVE is used to position the

text, which can now only be printed at graphics coordinates. Finally, the VDU 4

command returns the text cursor to normal so that PRINT TAB is usable

again.

Input

Earlier you saw that you can type in information while a program is running if

the program contains an INPUT statement:

10 MODE 135

280PRINT "How old are you" ;

360INPUT age

40 PRINT "So you're ";age;" years old."

50 PRINT "You don't look it !"

The INPUT statement in line 30 causes the computer to print a question mark,

and then wait for information to be typed at the keyboard. The computer

expects a number to be typed, because age is a numeric variable. Once

is pressed, the computer stores the value typed in the variable age. If you type

text rather than a number, the computer assumes the number is zero.

If you want to input text, you must use a string variable in the INPUT

statement:

10 MODE 135

20 PRINT "What is your name" ;

30 INPUT name$

40 PRINT "Hello " ;name$;'' and how are you?"

You can use a single INPUT statement to ask for several inputs:

10 MODE 135

20 PRINT "What is your name and age ";

30 INPUT name$, age

40 PRINT "Hello ";name$;". So you are " ;age;" years old. "

In this case the computer will expect two inputs, one a string and one a numeric

variable. They can either be separated by commas, or both can be followed by

The PRINT statement just before the INPUT is there to give a message to

remind you what you should type. This message can be included within the

INPUT statement:

10 MODE 135

20 INPUT "What is your name ";name$

30 PRINT "Hello " ;name$; ". Pleased to meet you."

C 27