The line A routines use about IK of variable
space, in which much of the system's graphics data is stored.
The location of this variable table may vary from machine to
machine, and from one version of TOS to another, but it can
always be found by calling the Line A Initialization function
(see Chapter 7 for more details). When this function is called,
the base address of the line A variable table is returned both
in register AO and DO. Starting at this base address, you can
locate the variables in the table by using their offset from the
base address. The following chart shows the offset of each
line A variable in decimal and hexadecimal format, its name,
and a description of its contents. Those variables whose
names start with V
__
are used by the ST BIOS character out
put routines.
-910 to -905 (— $38E to -$389)
RESERVED
This area is reserved for internal use.
-906 to -901 (-$388 to -$387)
CUR
__
FONT
A pointer to the current font header is stored here.
-902 to -855 (-$386 to -$355)
RESERVED
This area is reserved for internal use.
The Following 37 Words Hold the Sprite Definition
Block for the Mouse Pointer
-856 to -855 (-$356 to -$355)
M
__
POS
__
HX
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