Gobus - AMSTRAD cpc 6128 User Instruction

The single quote mark ' (which can be typed by holding down [SHIFT] and pressing
the 7 key) can be used as a substitute for : REM. For example:
HI
I
Zap the i n v a d e r s
[RETURN]
20
L
=
5
I
nu m b e r
0
f l i ve s [RETURN]
GOSUB
If there are a set of instructions within a program which are to be carried out a
number of times, these instructions need not be typed in repeatedly every time they
are needed in the program; instead, they can be made into a 'sub-routine' which when
required, can be called into action by the command GO SUB followed by the line
number. The end of the G 0 SUB -routine is marked by typing in the instruction
RE
T
URN. At this point the computer will return to the instruction that immediately
followed the GO SUB command which it had just obeyed.
For example, in the following program:
10 a=2
20 PRINT "here is the";a;"times table"
30 FOR b=1 TO 12
40 c=a*b
50 PRINT a;"x";b;"=";c
60 NEXT
70 PRINT
80
I
90 a=5
100 PRINT "here is the";a;"times table"
110 FOR b=1 TO 12
120 c=a*b
- -- -1-3
0 -P R I N T-
a;-" x
";b-;
"= " ;
c---- - - --- -- -- --
140 NEXT
150 PRINT
160
170
180
190
200
210
220
230'
240
250
260
270
280
290
300
310
a=8
PRINT "here is the";a;"times
FOR b=1 TO 12
c=a*b
PRINT a;"x";b;"=";c
NEXT
PRINT
I
a=9
PRINT "here is the";a;"times
FOR b=1 TO 12
c=a*b
PRINT a;"x";b;"=";c
NEXT
PRINT
Foundation Course
table"
table"
Chapter 1 Page 31