© 1985 ASCII CORP. / NIPPON GAKKI CO.
Page 26 of 108
© 2010-2015 Eugeny Brychkov
3.1.2. 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 6 high-order bits displayed and 2 low-order bits not
displayed. Pattern generator table base is stored in the register R#4.
Example of pattern generator table is provided below.
MSB LSB
Offset 7 6 5 4 3 2 1 0
0
1
2
3
4
5
6
7
Pattern number o (PN0)
8
9
10
11
12
13
14
15
Pattern number 1 (PN1)
●
●
●
●
●
●
●
●
●
2040
2041
2042
2043
2044
2045
2046
2047
Pattern number 255
(PN255)