Pengo Memory layout:

0000-7fff ROM
		0000 - 0fff	pengo u8
		1000 - 1fff	pengo u7
		2000 - 2fff	pengo u15
		3000 - 3fff	pengo u14
		4000 - 4fff	pengo u21
		5000 - 5fff	pengo u20
		6000 - 6fff	pengo u32
		7000 - 7fff	pengo u31
8000-83ff Video RAM
8400-87ff Color RAM
8800-8fff RAM

read:
9000-903f      DSW1
9040-907f      DSW0
9080-90bf      IN1
90c0-90ff      IN0

IN0:
    01 up
    02 down
    04 left
    08 right
    10 coin 1
    20 coin 2
    40 coin 3
    80 button 1

IN1:
    01 up
    02 down
    03 left
    04 right
    10 service
    20 start1
    40 start2
    80 button1

write:
8ff2-8ffd 6 pairs of two bytes:
          the first byte contains the sprite image number (bits 2-7), 
		Y flip (bit 0),
		X flip (bit 1);
		the second byte the color
9005      sound voice 1 waveform (nibble)
9011-9013 sound voice 1 frequency (nibble)
9015      sound voice 1 volume (nibble)
900a      sound voice 2 waveform (nibble)
9016-9018 sound voice 2 frequency (nibble)
901a      sound voice 2 volume (nibble)
900f      sound voice 3 waveform (nibble)
901b-901d sound voice 3 frequency (nibble)
901f      sound voice 3 volume (nibble)
9022-902d Sprite coordinates, x/y pairs for 6 sprites
9040      interrupt enable
9041      sound enable
9042      palette bank selector
9043      flip screen          
9044-9045 coin counters
9046      color lookup table bank selector
9047      character/sprite bank selector
9070      watchdog reset