Commodore Amiga A2000 - Page 196

BLTCON0 bits 15-12 = x1 modulo 15
BLTCON0 bits SRCA, SRCC, and SRCD = 1
BLTCON0 bit SRCB = 0
if exclusive-or line mode: _ _
then BLTCON0 LF control byte = ABC + AC
_
else BLTCON0 LF control byte = AB + AC
BLTCON1 bit LINEMODE = 1
BLTCON1 bit OVFLAG = 0
BLTCON1 bits 4-2 = octant number from Table
BLTCON1 bits 15-12 = start bit for line texture (0 = last significant
bit)
if (((4 * dy) - (2 * dx)) < 0):
then BLTCON1 bit SIGNFLAG = 1
else BLTCON1 bit SIGNFLAG = 0
if one pixel/row:
then BLTCON1 bit ONEDOT = 1
else BLTCON1 bit ONEDOT = 0
BLTSIZE bits 15-6 = dx + 1
BLTSIZE bits 5-0 = 2
NOTE
You must set the BLTSIZE register last as it starts the blit.
- Blitter Hardware 187 -