Yamaha V9938 Programmer's Manual page 39

3.4.1. Pattern Generator Table
The pattern generator table is a location in VRAM that stores patterns (font). Each
pattern has number from PN0 to PN255. The font displayed on the screen for each pattern
is constructed from 8 bytes, with all 8 bits of each byte displayed. Pattern generator table
base is stored in the register R#4. Example of pattern generator table is provided below.
MSB
Offset 7 6 5 4 3 2 1 0
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
●
●
●
2040
2042
2043
2044
2045
2046
2047
3.4.2. Pattern layout table settings
The pattern layout table is a map of the screen (per screen image). Every byte
location of the screen contains code of the pattern displayed at respective location. This
table has 32*24 (767) locations where defined patterns can be displayed. Pattern layout
© 1985 ASCII CORP. / NIPPON GAKKI CO.
LSB
Pattern number o (PN0)
Pattern number 1 (PN1)
● ●
● ●
● ●
Pattern number 255
(PN255)
Page 39 of 108
© 2010-2015 Eugeny Brychkov