Commodore Amiga A2000 - BLTCON0; BPLCON0

BLTCON0 040 W A Blitter control register 0
BLTCON1 042 W A Blitter control register 1
These two control registers are used together to control blitter
operations. There are two basic mode, area and line, which are selected
by bit 0 of BLTCON1, as shown below.
AREA MODE ("normal")
BIT BLTCON0 BLTCON1
15 ASH3 BSH3
14 ASH2 BSH2
13 ASH1 BSH1
12 ASA0 BSH0
11 USEA X
10 USEB X
09 USEC X
08 USED X
07 LF7 X
06 LF6 X
05 LF5 X
04 LF4 EFE
03 LF3 IFE
02 LF2 FCI
01 LF1 DESC
00 LF0 LINE(0)
ASH 3-0 Shift value of A source
BSH 3-0 Shift value of B source
USEA Mode control bit to use source A
USEB Mode control bit to use source B
USEC Mode control bit to use source C
USED Mode control bit to use destination D
LF 7-0 Logic function minterm select lines
EFE Exclusive fill enable
IFE Inclusive fill enable
FCI Fill carry input
DESC Descending (decreasing address) control bit
LINE Line mode control bit (set to 0)
- Appendix A 261 -