10 REM Combining a redefined character set with player-missile graphics
20 REM By Jason H. Moore, Ph.D.
30 REM November 10, 2019
40 REM Thanks to character set code example from The Creative Atari
50 REM Thanks to machine language example from Atari Graphics & Arcade Design
60 REM see CH5, p164 of Compute's First Book of Atari for PMG code
70 REM see file char-set-redefine-ML-PMG-comments.txt for verbose comments

100 REM INITIALIZE MEMORY MAP AND GRAPHICS

110 MEMTOP=PEEK(106)
120 GRTOP=MEMTOP-4
130 POKE 106,GRTOP
140 PM=GRTOP-20
150 PMBASE=256*PM
160 CHRAM=GRTOP*256

170 GRAPHICS 2+16:POKE 752,1
180 SETCOLOR 0,0,4
190 SETCOLOR 2,0,0

200 REM INITIALIZE PLAYER 0 COLOR AND POSITION

210 PCOL0=216
220 POKE 704,PCOL0
230 PXMEM=53248:PYMEM=1780:PHMEM=1784
240 P0X=120:P0Y=80

250 POKE 756,GRTOP

300 REM SET UP PLAYFIELD AND PLAYER MISSILE GRAPHICS

400 GOSUB 5000
500 GOSUB 6000

600 REM *** MAIN LOOP ***

610 REM SET PLAYER POSITION AND HEIGHT & CHECK JOYSTICK

620 POKE PHMEM,14
630 POKE PXMEM,P0X:POKE PYMEM,P0Y
640 GOSUB 700
650 GOTO 620
660 END

700 REM PLAYER MOVEMENT CALCULATIONS

710 JOY = STICK(0)
720 IF JOY=15 THEN RETURN
730 IF JOY=11 THEN P0X=P0X-2
740 IF JOY=7 THEN P0X=P0X+2
750 IF JOY=13 THEN P0Y=P0Y+2
760 IF JOY=14 THEN P0Y=P0Y-2
770 IF P0X>190 THEN P0X=50
780 IF P0X<50 THEN P0X=190
790 IF P0Y>205 THEN P0Y=45
800 IF P0Y<45 THEN P0Y=205
810 RETURN

5000 REM READ IN MACHINE LANGUAGE ROUTINE FOR MOVING CHAR SET

5010 FOR I=0 TO 49
5020 READ DAT:POKE 1536+I,DAT
5030 NEXT I
5040 M=USR(1536,GRTOP,1,4)

5050 REM REDEFINE CHARS A TO J

5060 CHRAM=CHRAM+264
5070 FOR I=1 to 16
5080 FOR ADDR=CHRAM TO CHRAM+7
5090 READ DAT:POKE ADDR,DAT
5100 NEXT ADDR
5110 CHRAM=CHRAM+8
5120 NEXT I

5130 REM DRAW DEATH STAR

5140 POSITION 3,2
5150 PRINT #6; "AEIM"
5160 POSITION 3,3
5170 PRINT #6; "BFJN"
5180 POSITION 3,4
5190 PRINT #6; "CGKO"
5200 POSITION 3,5
5210 PRINT #6; "DHLP"
5220 POSITION 3,6

5230 REM DRAW STARS

5240 POSITION 1,1
5250 PRINT #6; "*"
5260 POSITION 12,2
5270 PRINT #6; "*"
5280 POSITION 3,10
5290 PRINT #6; "*"
5300 POSITION 14,8
5310 PRINT #6; "*"
5320 POSITION 18,5
5330 PRINT #6; "*"
5340 POSITION 18,5
5350 PRINT #6; "*"

5400 RETURN

6000 REM INITIALIZE VBLANK FAST PLAYER MOVEMENT ROUTINE

6010 FOR I=1536 TO 1706
6020 READ A:POKE I,A
6030 NEXT I

6040 FOR I=1774 TO 1787
6050 POKE I,0
6060 NEXT I

6100 REM INITIALIZE PLAYER-MISSILE GRAPHICS

6110 REM First zero out the player memory area

6120 FOR I=PMBASE+1023 TO PMBASE+2047
6130 POKE I,0
6140 NEXT I

6150 REM Next load the player 0 shape data into memory

6160 FOR I=PMBASE+1025 TO PMBASE+1038
6170 READ A:POKE I,A
6180 NEXT I

6200 REM Initialize the player-missle graphics options

6210 POKE 559,62
6220 POKE 623,1
6230 POKE 1788,PM+4
6240 POKE 53277,3
6250 POKE 53256,1
6260 POKE 54279,PM

6270 X=USR(1696)

6300 RETURN

7000 REM MACHINE LANGUAGE ROUTINE FOR MOVING CHAR SET

7010 DATA 104,169,224,133,206,104,104,133,204,104,104,201,1,240,4,230
7020 DATA 206,230,204,104,104,141,176,6,169,0,133,205
7030 DATA 133,203,168,177,205,145,203,200,208,249,230
7040 DATA 206,230,204,206,176,6,208,240,96,0,0

7100 REM DATA FOR REDEFINED CHARACTERS (DEATH STAR)

7110 DATA 0,0,3,7,15,15,31,31
7120 DATA 63,63,127,127,127,127,127,127
7130 DATA 0,127,127,127,127,127,63,63
7140 DATA 31,31,15,15,7,1,0,0
7150 DATA 0,63,255,255,255,255,255,207
7160 DATA 135,3,3,135,207,255,255,255
7170 DATA 0,255,255,255,255,255,255,255
7180 DATA 255,255,255,255,255,255,63,0
7190 DATA 0,252,255,255,255,255,255,255
7200 DATA 255,255,255,255,255,255,255,255
7210 DATA 0,255,255,255,255,255,255,255
7220 DATA 255,255,255,255,255,255,252,0
7230 DATA 0,0,128,224,240,240,248,248
7240 DATA 252,252,254,254,254,254,254,254
7250 DATA 0,254,254,254,254,254,252,252
7260 DATA 248,248,240,240,224,128,0,0

8000 REM VBLANK INTERRUPT ROUTINE (FAST PLAYER MOVEMENT)

8010 DATA 162,3,189,244,6,240,89,56,221,240,6,240,83,141,254,6,106,141
8020 DATA 255,6,142,253,6,24,169,0,109,253,6,24,109,252,6,133,204,133
8030 DATA 206,189,240,6,133,203,173,254,6,133,205,189,248,6,170,232,46,255
8040 DATA 6,144,16,168,177,203,145,205,169,0,145,203,136,202,208,244,76,87
8050 DATA 6,160,0,177,203,145,205,169,0,145,203,200,202,208,244,174,253,6
8060 DATA 173,254,6,157,240,6,189,236,6,240,48,133,203,24,138,141,253,6
8070 DATA 109,235,6,133,204,24,173,253,6,109,252,6,133,206,189,240,6,133
8080 DATA 205,189,248,6,170,160,0,177,203,145,205,200,202,208,248,174,253,6
8090 DATA 169,0,157,236,6,202,48,3,76,2,6,76,98,228,0,0,104,169
8100 DATA 7,162,6,160,0,32,92,228,96

9000 REM PLAYER SHAPE DATA (DARTH VADER TIE FIGHTER)

9010 DATA 66,129,129,153,153,255,255,255,255,153,153,129,129,66