Atari ST series - Page 337

The Line A Variable Table
+ 026 to +027 (+ $01A to + $01B)
COLBIT1
for plane 1 of the display.
( + $01C to +$01D)
COLBIT2
for plane 2 of the display.
( + $01E to +$01F)
COLBIT3
for plane 3 of the display.
( + $020 to +$021)
LSTLIN
This is a flag which indicates whether the last pixel of a line
should be drawn. A zero value means that the pixel is
drawn, while a nonzero value means that it is not drawn.
This flag is used for drawing a series of connected lines us
ing the XOR writing mode, so that the common endpoint
doesn't disappear when the second line is drawn.
+ 034 to +035 ( + $022 to +$023)
LNMASK
The line-draw pattern mask.
+ 036 to +037 ( + $024 to +$025)
WMODE
The VDI Writing mode to use for drawing.
Mode
Meaning
0
Replace
1
Transparent,
2 XOR
3
Reverse transparent
For TextBlt, the BitBlt logic modes may be stored here i
well:
Mode
Logic Operation
Description
4
D1 = 0
Clear destination block
5
D1 = S AND D
6
D1 = S AND (NOT D)
7 D1 = S Replace mode
8
D1 = (NOT S) AND D Erase mode
The color bit plane value
+ 028 to +029
The color bit plane value
+ 030 to +031
The color bit plane value
+ 032 to +033
329