© 1985 ASCII CORP. / NIPPON GAKKI CO.
Page 51 of 108
© 2010-2015 Eugeny Brychkov
3.7.1. Pattern layout table settings
The pattern layout table is a map of the screen (per screen image). Every byte
location of the screen contains color codes for
four
dots. This is bitmap graphics mode,
and there’s no pattern generator table.
Columns
0
1
2
3
511
←
X
0
0, 0
1, 0
2, 0
3, 0
…
510, 0
511, 0
1
0, 1
1, 1
2, 1
3, 1
…
…
511, 1
…
…
… … … … …
… …
…
… X,
Y … …
191
0, 191
1, 191
2, 191
…
…
…
511,191 LN=0
… … … … … … …
… … … … … … …
211
0, 211
1, 211
2, 211
…
…
…
511,211 LN=1
Rows
↑
Y
MSB
7 6 5 4 3 2 1 0
LSB
0
Color code
for (0, 0)
Color code
for (1, 0)
Color code
for (2, 0)
Color code
for (3, 0)
Base address
1
Color code
for (4, 0)
Color code
for (5, 0)
Color code
for (6, 0)
Color code
for (7, 0)
127
Color code
for (508, 0)
Color code
for (509, 0)
Color code
for (510, 0)
Color code
for (511, 0)
128
Color code
for (0, 1)
Color code
for (1, 1)
Color code
for (2, 1)
Color code
for (3, 1)
27135
Color code
for (508, 211)
Color code
for (509, 211)
Color code
for (510, 211)
Color code
for (511, 211)
Pattern layout table base address is stored in register R#2, and corresponds to the
cell (0, 0) in the picture above.
MSB
7 6 5 4 3 2 1 0
LSB
R#2
0 A16
A15 1 1 1 1 1
Pattern layout
table base
address