Atari 400 Technical Reference Manual page 298

ERR LINE ADDR B1 B2 B3 B4 INTERRUPT HANDLER
PAGE 37
1548
. PAGE
1549
1550 SUBROUTINE TO SET VERTICAL BLANK VECTORS AND TIMERS
1551 ENTRY X=HI,Y=LO BYTE TO SET
1552 A= 1-5 TIMERS 1-5
1553
6 IMM VBLANK
1554
7 DEF VB LANK
1555
1556 E8ED OA SETVBL: ASL A ; MUL BY 2
1557 E8EE 80 20 02 STA INTEMP
1558 E8F1 8A TXA
1559 E8F2 A2 05 LOX
#5
1560 E8F4 80 OA 04 STA WSYNe iWASTE 20 CPU CYCLES
1561 E8F7 CA SETLOP: DEX iTO ALOWD VB LANK TO HAPPEN
1562 E8F8 DO FD BNE SETLOP
i IF THIS IS LINE "7C"
1563 E8FA
AE 20 02 LOX INTEMP
1564 E8FD 90 17 02 STA COTMV1-1,X
1565 E900 98 TYA
1566 E901 90 16 02 STA CDTMV1-2,X
1567 E904
60
RTS
1568
1569 i EXIT FROM VERTICAL BLANK
1570
1571 E905 68 XITVBL: PLA
i
UNSTACK Y
1572 E906 A8 TAY
1573 E907 68 PLA i UNSTACK X
1574 E908 AA TAX
1575 E909 68 PLA i UNSTACK A
1576 E90A 40 RTI iAND GO BACK FROM WHENCE.
1577 00E6 PIRGH PIRG/256
1578 00F3 PIRGL (-256)*PIRGH+PIRG
1579 00E7
PNMIH
:::;
PNMI/256
1580 0091
PNMIL =
(-256)*PNMIH+PNMI
1581
i
SPARE BYTE OR MODULE TOO LONG FLAG
1582 E90B CRNTP2
=*
1583 *=$14
1584 0014 39 INTSPR: . BYTE
SIOORG-CRNTP2 jAGINTHV IS TOO LONG