SECTION 6
Conversions and Interfaces
6-36 PEN*KEY
R
6200/6300 Hand-Held Computer Programmer’s Reference Guide
INT 10h, Function AH = 09h: Write Character and Attribute at Cursor Position
BIOS, FONTMAP
Writes the character and attribute at the current cursor position, for the selected
page. The character is written the number of times indicated by the value in CX.
If the number of repeats exceed the end of a line, characters wrap to the next
line. In graphics modes, wrapping does not occur. All ASCII values from 0ć256
produces a display, including control characters. Control characters do not
produce control functions but do cause special characters to display. Control
characters do not alter the cursor position. The cursor is never advanced by the
function. Pages that are not active can be written to.
In graphic modes, the bit map for ASCII values 128ć255 are stored in a table
pointed at by location 0:10Ch in the interrupt table location (INT 43h). This
value is initialized to an internal table maintained by the BIOS. This value may
be altered to point to a userĆdefined table. The BIOS maintains a separate bit
map table for ASCII values 0ć127. The value in BL is the foreground color of the
character being written, and if bit seven of BL is set, the color value is XORed
with the current contents of the screen position.
On Entry:
AH = 09h
AL = Value of the character
BH = Display page number
BL = Character attribute (or color in graphics mode)
CX = Count of characters to write
On Return:
None
INT 10h, Function AH = 0Ah: Write Character Only at Cursor Position
BIOS, FONTMAP
Performs the same as Function 9, except that the attribute (of the previous
character at the current cursor location) remains unchanged.
On Entry:
AH = 0Ah
AL = Value of the character
BH = Display page
CX = Count of characters to write
On Return:
None
6. Conversions and
Interfaces
