Commodore VIC-20 - Page 320

306 The VIC 20 User Guide
TABLE 8-3: 6560 VIC Chip Functions by Memory Location
Location (Decimal)
Location (Hex)
Byte Function
36864
9000
[U 12
I
2
I
2
I
2
I
2
I
2
I
2
I
36865 9001
I
3
I
3
I
3
I
3
I
3
I
3
I
3
I
3
I
36866 9002
wi
4
I
4
I
4
I
4
I
4
I
4
I
4
I
36867
9003
[Ill
5
I
5
I
5
I
5
I
5
I
5
I
GJ
36868
9004
7 7
7 7
I
7
I
7
I
7
I
7
I
36869
9005 8 8 8 8
I
I 9
I
9
I
9
I
9
I
36870
9006
10 10 10 10 10
10
10
10
36871 9007
II II II II II II II
II
36872
9008
112
12 12 12 12 12 12
12
36873 9009 13 13 13 13 13 13 13 13
36874 900A 14
14 14
14 14 14 14 14
36875
9008 15 15 15 15
15
1 5
I 5
15
36876
900C
16
16
16 16 16 16 16 16
36877
9000
17 17
17
17
17
17
17 17
36878
900E
19 19 19
19 18 18 I 8 18
36879
900F
20 20 20 20
~
I 2
I
22
I
2
I
I Interlaced video (I = interlaced; 0 = noninterlaced).
2 Horizontal position
of screen display area. On power-up this location contains 5. To move
the display area left, enter a lower value. Entering a higher value moves
it to the right.
3 Vertical position
of screen display area. On power-up this location contains 25. Increasing
this number lowers the screen, and lowering this number raises the screen.
4 Screen width control. This location sets the number
of columns the VIC will display. If it
is 22 (which it normally is), the VIC will display 22 characters in each line. Reducing this
number will reduce the number
of characters in a line. Any number higher than 26 will
result in
27 columns (the maximum) being displayed.
5 Screen height control. This location allows you to change the number
of rows displayed.
The VIC can display from 0 to
23 rows.