.TITLE     STARFIGHTER WORK BY TOD FRYE

     .SBTTL     2-23-84

     .ENABLE     AMA

     .ASECT

     .RADIX     16

; PIA AND TIMER

SWCHA     =     280

; JOYSTICKS

; R-L-U-D

SWCHB     =     282

; D7  P1 DIFF

; D6  P0 DIFF

; D3  COLOR B/W

; D2  SELECT

CTLSWA     =     281

CTLSWB     =     283

INTIM     =     284

TIMER     =     284

SETIM1     =     294

TIM8T     =     294

SETIM8     =     294

TIM64T     =     296

SETIM64     =     296

SETIMK     =     297

; STELLA REGISTERS

VSYNC     =     00

VBLANK     =     01

WSYNC     =     02

RSYNC     =     03

NUSIZ0     =     04

NUSIZ1     =     05

COLUP0     =     06

COLUP1     =     07

COLUPF     =     08

COLUBK     =     09

CTRLPF     =     0A

REFP0     =     0B

REFP1     =     0C

PF0     =     0D

PF1     =     0E

PF2     =     0F

RESP0     =     10

RESP1     =     11

RESM0     =     12

RESM1     =     13

RESBL     =     14

AUDC0     =     15

AUDC1     =     16

AUDF0     =     17

AUDF1     =     18

AUDV0     =     19

AUDV1     =     1A

GRP0     =     1B

GRP1     =     1C

ENAM0     =     1D

ENAM1     =     1E

ENABL     =     1F

HMP0     =     20

HMP1     =     21

HMM0     =     22

HMM1     =     23

HMBL     =     24

VDELP0     =     25

VDELP1     =     26

VDELBL     =     27

RESMP0     =     28

RESMP1     =     29

HMOVE     =     2A

HMCLR     =     2B

CXCLR     =     2C

CXM0P     =     30

CXM1P     =     31

CXP0FB     =     32

CXP1FB     =     33

CXM0FB     =     34

CXM1FB     =     35

CXBLPF     =     36

CXPPMM     =     37

INPT0     =     38

INPT1     =     39

INPT2     =     3A

INPT3     =     3B

INPT4     =     3C

INPT5     =     3D

     .=80

; ZERO PAGE

FRAME:     .=.+1

LINE:     .=.+1

SEEDL:     .=.+1

SEEDH:     .=.+1

T0:     .=.+1

T1:     .=.+1

T2:     .=.+1

T3:     .=.+1

WVP0L:     .=.+1

WVP0H:     .=.+1

WVP0:     .=.+1

FRQ0L:     .=.+1

FRQ0H:     .=.+1

DURC0:     .=.+1          ; DURATION COUNTER

TUNPTR:     .=.+2          ; NOTE POINTER

PHRASE:     .=.+1          ; PHRASE NUMBER

MOD:     .=.+1          ; TUNE MODULATION OFFSET

LOGPTR:     .=.+2

P0CTR:     .=.+1

COLOR:     .=.+5

P0X:

XPOS:     .=.+5

VPOS:     .=.+5

SHIP:     .=.+5

CHP0:     .=.+2

CHP1:     .=.+2

CHP2:     .=.+2

CHP3:     .=.+2

CHP4:     .=.+2