qa.hlp (Table of Contents; Topic list)
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Int 10H Function 09H
   Summary  Notes  Back
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    In graphics modes, the replication factor in CX produces a valid result
    only for the current row. If more characters are written than there are
    remaining columns in the current row, the result is unpredictable.
 
    All values of AL result in some sort of display; control characters, in-
    cluding bell, backspace, carriage return, and line feed, are not recog-
    nized as special characters and do not affect the cursor position.
 
    After a character is written, the cursor must be moved explicitly with
    Int 10H Function 02H to the next position.
 
    To write a character without changing the attribute at the current cur-
    sor position, use Int 10H Function 0AH.
 
    If this function is used to write characters in graphics mode and bit 7
    of BL is set (1), the character will be exclusive-OR'd (XOR) with the
    current display contents. This feature can be used to write characters
    and then "erase" them.
 
    For the CGA and PCjr in graphics modes 04H-06H, the bit patterns for
    character codes 80H-FFH are obtained from a table whose address is
    stored in the vector for Int 1FH. On the PCjr, the address of the table
    for character codes 00-7FH is stored in the vector for Int 44H. Alterna-
    tive character sets can be installed by loading them into memory and
    updating this vector.
 
    For the EGA, MCGA, and VGA in graphics modes, the address of the char-
    acter definition table is stored in the vector for Int 43H. See Int 10H
    Function 11H.
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