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4.6 Pattern name table (page)

The pattern name table (or page) stores the pattern name data in the form of a table in the VRAM, and arranges the pattern when character patterns are laid out in a square of 64 x horizontal 64 cells. The pattern name data specifies the start address of the character pattern stored in VRAM and other control information for each character pattern.
The pattern name data on the pattern name table is 1 word or 2 words. In the case of 1 word, the auxiliary data of the lower 10 bits of the pattern name control register is added to make up for the missing bits.

■ Data structure of pattern name table

The VRAM capacity required for the pattern name table of 64 cells horizontally x 64 cells vertically (one page), and the boundary stored in VRAM vary depending on the pattern name data size (number of words) and character size. Table 4.4 and Figure 4.8 show the pattern name table capacity and table data structure.

Table 4.4 Pattern name table capacity and page boundary for one page 
 Pattern name 
 Data size 
 Character size 
 Capacity per page 
 
 Poundary 
 1 word 
 1 horizontal cell x 1 vertical cell 
 8192 bytes 
 2000H 
 2 horizontal cells x 2 vertical cells 
 2048 bytes 
 800H
 2 words 
 1 horizontal cell x 1 vertical cell 
 16384 bytes 
 4000H 
 2 horizontal cells x 2 vertical cells 
 4096 bytes 
 1000H

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