Radio Shack TRS-80 Model 100 Basic Manual page 109

Experiment #4 Axis Scale
You can add "tick" marks to your axes to indicate a relative scale. Clear the display
and list your program to confirm that it is:
50 CLS
100 LINE(238,54)-(33,54)
150 LINE -(33t0)
Enter the following new lines to your program:
200 FOR X=33 TO
300 PSET (X,53)
500 FOR Y-51 TO
600 PSET (34,Y)
238 STEP 24
NEXT X
o
STEP -8
: NEXT Y
List the entire program to confirm that it is now:
50
10.O
150
200
300
500
600
CLS
LINE (238,54)
LINE -(33,O)
FOR X - 33 TO
PSET (X,53) :
FOR Y = 51 TO
PSET (34,Y) :
238 STEP 24
NEXT X
o
STEP -8
NEXT Y
Execute this program to confirm that it now displays:
Lines 28t) ·388 This FOR/NEXT loop displays the tick marks on the horizontal axis.
The first tick mark is displayed at coordinate (33,53), the second at (57,53), and so
On. The last tick mark will be at (225,53).
Lines S8t) . 689 This FOR/NEXT loop displays the tick marks on the vertical axis.
The first tick mark is displayed at coordinate (34,51), the second at (34,43), and so
On. The last tick mark will be at (34,3).
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