Atari 400 Technical Reference Manual page 383

ERR LINE ADDR B1 B2 B3 B4
DISPLAY HANDLER -- 10-30-78 -- DISPLC
PAGE 122
5491 FDB7 85 54
STA ROWCRS
5492 FDB9 A2 00 LDX
#0 iAND SUBTRACT ENDPT FROM ROWAC
5493 FDBB 20 7A FA
JSR SUB END
5494 FDBE 18
DRAW6: CLC
iDO SAME FOR COLUMN (DOUBLE BYTE ADD)
5495 FDBF A5 72 LDA
COLAC
i
ADD
5496 FDCl 65 77
ADC DELTAC
5497 FDC3 85 72
STA COLAC
5498
FDC5 A5 73 LDA
COLAC+l
5499 FDC7 65 78
ADC DELTAC+l
5500 FDC9 85 73
STA COLAC+l
5501 FDCB C5 75
CMP ENDPT+l
iCOMPARE HIGH BYTE
5502 FDCD 90 27 BCC
DRAW8
5503
FDCF DO 06 BNE
DRAW6A
5504 FDDl A5 72
LDA COLAC
iCOMPARE LOW BYTE
SSOS FDD3 CS 74
CMP ENDPT
5506 FDD5 90 iF
BCC DRAW8
5507
FDD7 24 7A DRAW6A: BIT
COL INC
i+
OR - ?
5508 FDD9 10 10
BPL
DRAW6B
5509 FDDB C6 55
DEC COLCRS
iDO DOUBLE BYTE DECREMENT
5510 FDDD AS 55
LDA COLCRS
5511 FDDF C9 FF CMP
#$FF
5512 FDE1 DO OE
BNE DRAW7
5513
FDE3 AS 56 LDA
COLCRS+l
5514 FDE5 FO OA
BEG DRAW7
iDON'T DEC IF ZERO
5515 FDE7 C6 56
DEC COLCRS+1
5516
FDE9 10 06 BPL
DRAW7
i
(UNCONDITIONAL)
5517 FDEB E6 55
DRAW6B: INC COLCRS
iDO DOUBLE BYTE INCREMENT
5518 FDED DO 02 BNE
DRAW7
5519 FDEF E6 56 INC
COLCRS+1
5520 FDF1 A2 02
DRAW7: LOX
#2 iAND SUBTRACT ENDPT FROM COLAC
5521 FDF3 20 7A FA
JSR SUB END
5522 FDF6 20 96 FA
DRAW8: JSR RANGE
5523 FDF9 20 EO F5 JSR
OUTPLT
i
PLOT POINT
5524 FDFC· AD B7 02 LOA
FILFLG
i
TEST RIGHT FILL
5525
FDFF FO 2F BEG DRAW9
5526 FEOl 20 9D FC
JSR PHACRS
5527 FE04 AD FB 02
LOA ATACHR
5528 FE07 8D BC 02 STA
HOLD4
5529
FEOA A5 54 DRAW8A: LOA ROWCRS
iSAVE ROW IN CASE OF CR
5530 FEOC 48
PHA
5531 FEOD 20 DC F9
JSR INCRSA
iPOSITION CURSOR ONE PAST DOT
5532 FE10 68 PLA
iRESTORE ROWCRS
5533
FEll 85 54 STA ROWCRS
5534 FE13 2096 FA
DRAW8C: JSR RANGE
5535 FE16 20 A2 F5
JSR GETPLT
i GET DATA
5536 FE19 DO OC
BNE DRAW8B
iSTOP IF NON-ZERO DATA IS ENCOUNTERED
5537 FE1B AD FD 02
LDA FILDAT iFILL DATA
5538
FE1E 80 FB 02 STA
ATACHR
5539
FE21 20 EO F5 JSR OIJTPLT
i
DRAW IT
5540 FE24 4C OA FE
JMP DRAW8A
i
LOOP
5541 FE27 AD BC 02 DRAW8B: LOA
HOLD4
5542 FE2A 8D FB 02 STA ATACHR
5543 FE2D 20 A8 FC
JSR PLACRS
5544 FE30 38 DRAW9: SEC
iDO DOUBLE BYTE SIJBTRACT