Atari ST series Technical Reference Manual page 339

pattern, while a nonzero value indicates a multiplane fill pat­
tern.
+ 054 to +055
Clipping flag. A 0 here turns clipping off, while any other
value turns it on.
+ 056 to +057
Left edge of clip rectangle.
+ 058 to +059
Right edge of clip rectangle.
+ 060 to +061
Top of clip rectangle.
+ 062 to +063
Bottom of clip rectangle.
+ 064 to +065
Accumulator for text scaling. Should be set to $8000 before
each TextBlt that requires scaling.
+ 066 to +067
Scaling increment. For scaling up, DDAINC = 256 * (Size2
- Sizel) / Sizel. For scaling down, DDAINC = 256 * (Size2)
/ Sizel, where Sizel is the actual character point size, and
Size2 is the scaled character size.
+ 068 to +069
Text scaling direction (0 = down, 1 = up)
+ 070 to +071
Monospaced font flag.
The Line A Variable Table
CLIP
XINCL
XMAXCL
YMINCL
YMAXCL
XDDA
DDAINC
SCALDIR
MONO
( + $036 to + $037)
( + $038 to +$039)
( + $03A to +$03B)
(+$03C to + $03D)
( + $03E to +$03F)
( + $040 to + $041)
( + $042 to + $043)
( + $044 to +$045)
( + $046 to +$047)
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