bit playfield

  dim pf_row = a
  dim pf_col = b
  dim ds_start_bit = c
  dim current_bit = d
  dim current_byte = e
  dim ds_byte = e
  dim ds_col = g
  dim ds_row = h

printpf

  ds_byte = ds_col / 8
  ds_byte = ds_row * 8 + ds_byte
  ds_start_bit = ds_col & 7

  for pf_row = 0 to 10
  current_bit = setbits[ds_start_bit]
  current_byte = map[ds_byte]

     for pf_col = 0 to 31
     if current_byte & current_bit then pfpixel pf_col pf_row on else pfpixel pf_col pf_row off
     current_bit = current_bit / 2

     rem   if current_bit = 0 then done with one
     rem   data statement byte so go to the next
     rem   get the corresponding map byte
     rem   and reset current_bit to the first bit column
     if current_bit = 0 then ds_byte = ds_byte + 1 : current_byte = map[ds_byte] : current_bit = $80
     next

  rem   we have incremented ds_byte by 4
  rem   in the pf_col loop
  rem   8 bytes per data statement row
  rem   we need to advance 4 more to go to the
  rem   next row in the data statement
  ds_byte = ds_byte + 4
  next


 data setbits
 %10000000, %01000000, %00100000, %00010000
 %00001000, %00000100, %00000010, %00000001
end

 data map
 %11111111, %11111111, %11111111, %11111111, %11111111, %11111111, %11111111, %11111111
 %10000000, %00000000, %00000000, %00000001, %10000000, %00000000, %00000000, %00000001
 %10100000, %00000000, %00111111, %11111001, %10100000, %00000000, %00111111, %11111001
 %10100000, %00100000, %00100000, %00110001, %10100000, %00100000, %00100000, %00110001
 %10100000, %00100000, %00100000, %11000001, %10100000, %00100000, %00100000, %11000001
 %10100000, %00101111, %11100011, %00000001, %10100000, %00100001, %11100011, %00000001
 %10100000, %00111000, %00001100, %00000001, %10100000, %00000000, %00001100, %00000001
 %10100000, %00000000, %00110000, %00000001, %10100000, %00000000, %00110000, %00000001
 %10111111, %11111111, %11000000, %00000001, %10111111, %11000001, %11000000, %00000001
 %10000000, %00000000, %00000000, %00000001, %10000000, %00000000, %00000000, %00000001
 %11111111, %11111111, %11111111, %11111111, %11111111, %11111111, %11111111, %11111111
 %10101010, %01010101, %01010101, %01010100, %01010101, %01010001, %01010101, %01010101
 %10000000, %00000000, %00000000, %00000001, %00000000, %00000000, %00000000, %00000001
 %10000000, %00000000, %00000001, %10000001, %00100000, %00000000, %00111111, %11111001
 %10000000, %00100000, %00000000, %00110001, %00100000, %00100000, %00100000, %00110001
 %10000000, %00100000, %00000000, %11000001, %00100000, %00100000, %00100000, %11000001
 %10000000, %00101111, %10000011, %00000001, %00100000, %00100111, %11100011, %00000001
 %10000000, %00111000, %00000000, %00000001, %00100000, %00111000, %00001100, %00000001
 %10000000, %00000000, %00000000, %00000001, %00100000, %00000000, %00110000, %00000001
 %10000000, %11111111, %00000000, %00000001, %10000011, %10000011, %11000000, %00000001
 %10000000, %00000000, %00000000, %00000001, %10000000, %00000000, %00000000, %00000001
 %11111111, %11111111, %11111111, %11111111, %11111111, %11111111, %11111111, %11111111
end