Yamaha V9938 Programmer's Manual page 35

3.3.1. Pattern Generator Table
Each pattern is made up of four color blocks. These patterns are of size of 8*8 for the
screen display of 256*192 dots.
← 8 dots
Block A Block B
Block C Block D
MSB
There're four color blocks (8 bytes) for each pattern layout location. Specific color
block is used to display depending on the y-coordinate.
MSB
A B
C D
E F
G H
I J
K L
M N
O P
Start of the pattern generator table should be set in register R#4.
3.3.2. Pattern layout table settings
The pattern layout table is a map of the screen (per screen image), containing one
byte for each screen location. Each byte specifies unique pattern number. Start of the
pattern name table should be set in register R#2.
© 1985 ASCII CORP. / NIPPON GAKKI CO.
→
For each block A, B, C, and D sixteen colors can be
↑
specified. Two bytes are used for each pattern.
8 dots
↓
7 6 5
Color code A
Color code C
7 6 5 4
Color code A
Color code C
Color code E
Color code G
Color code I
Color code K
Color code M
Color code O
4 3 2
Color code B
Color code D
3 2 1 0
Color code B
Color code D
Color code F
Color code H
Color code J
Color code L
Color code N
Color code P
Page 35 of 108
1 0 LSB
LSB
Color of the pattern when
y=0, 4, 8, 12, 16 or 20
Color of the pattern when
y=1, 5, 9, 13, 17 or 21
Color of the pattern when
y=2, 6, 10, 14, 18 or 22
Color of the pattern when
y=3, 7, 11, 15, 19 or 23
© 2010-2015 Eugeny Brychkov