54279



        E 704,160: POKE 53256,2
     30   MEM = PEEK(106) - 8
     40   POKE 54279, MEM: POKE 53277,3: S
        TART = MEM * 256 + 1024
     50   FOR LOOP = 100 TO 119: READ BYTE
        : POKE START + LOOP, BYTE: NEXT LO
        OP
     60   DATA 16,16,56,40,40,56,40,40,40
     70   DATA 124,84,124,84,254,146,254,1
        70,170,68
     100  END

     You can change the color, width, resolution, and horizontal
     position of the player in the example by altering the registers
     used above.

     Each player is one byte (eight bits) wide. Single line resolution
     P/M characters (POKE 559,62) can be up to 256 bytes high.
     Double line resolution P/M characters (POKE 559,46) can be up
     to 128 bytes high. In either case, they can map to the height of the
     screen. Missiles have the same height, but are only two bits wide
     each. Four missiles can be combined into a fifth player by setting
     BIT 4 of location 623 ($26F). You need not fill the entire height of
     a P/M character, but you should POKE unused bytes with zero to
     eliminate any screen garbage. You can do this by:

     FOR N = PMBASE + 1024 TO PMBASE + 2048:
      POKE N,0: NEXT N

     where PMBASE is the starting address of the reserve memory
     area. In double line resolution, change the loop value to N =
     PMBASE + 512 TO PMBASE + 1024. Here's a short machine
     language routine to do the same thing. You would put the start
     address of the area to be loaded with zero and the number of
     bytes to be cleared in with the USR call as the first two
     parameters. In this example, I have arbitrarily chosen 38012 and
     2048 for these values.

     10   START = 38012: BYTE = 2048: DIM
        PGM$(42)
     20   FOR LOOP = 1 TO 42: READ ML: PGM
        $(LOOP, LOOP) = CHR$(ML): NEXT LOO
        P
     30   DATA 104,104,133,204,104,133,203
        ,104,133,206,104
     40   DATA 133,205,166,206,160,0,169,0
        ,145,203,136
     50   DATA 208,251,230,204,202,48,6,20
        8,244,164