” Kanji ROM

” Kanji ROM I/O port

AddressR/WDescription
E8hW Kanji ROM address lower 8 bits setting
R Read the right 8 bits of the Kanji ROM font (even lines for half-width and quarter-width characters)
E9hW Kanji ROM address upper 8 bits setting
R Read the left 8 bits of the Kanji ROM font (odd lines for half-width and quarter-width characters)
EAhW Start reading Kanji ROM
EBhW Finish reading Kanji ROM
EChW Second level Kanji ROM address lower 8 bits setting
R Read the right 8 bits of the second level Kanji ROM font.
EDhW Second level Kanji ROM address upper 8 bits setting
R Read the left 8 bits of the second level Kanji ROM font.

” JIS code to Kanji ROM address conversion

EHalf-width characters (0020h to 00FFh)
E1/4 square characters (0100h to 01FFh)
ENon-Kanji (2120h to 277Fh)
EFirst level Kanji (3020h to 4F5Fh)
ESecond level Kanji (5020h to 6F7Fh)
ESecond level Kanji (7020h to 705Fh)

” Kanji ROM access method

  1. Set the lower 8 bits of the Kanji ROM address to E8h
  2. Set the upper 8 bits of the Kanji ROM address to E9h
  3. Output some data to EAh and start Kanji ROM access
  4. Add 8 clock waits
  5. Input character font data from E9h (ECh)
  6. Input character font data from E8h (EDh)
  7. Output some data to EBh and end Kanji ROM access
  8. Add 1 to Kanji ROM address and loop