Memory Map Notes
Progam starts at $0000
RAM $2000-$3FFF
$2000-$23FF Stratch Area, Stack adds backwards from $2400
$2400-$3FFF Video Memory
ROM info from MAME
ROM_START( spcenctr )
ROM_REGION( 0x10000, REGION_CPU1, 0 )
ROM_LOAD( "4m33.h", 0x0000, 0x0800, CRC(7458b2db)
ROM_LOAD( "4m32.g", 0x0800, 0x0800, CRC(1b873788)
ROM_LOAD( "4m31.f", 0x1000, 0x0800, CRC(d4319c91)
ROM_LOAD( "4m30.e", 0x1800, 0x0800, CRC(9b9a1a45)
ROM_LOAD( "4m29.d", 0x4000, 0x0800, CRC(294d52ce)
ROM_LOAD( "4m28.c", 0x4800, 0x0800, CRC(ce44c923)
ROM_LOAD( "4m27.b", 0x5000, 0x0800, CRC(098070ab)
ROM_LOAD( "4m26.a", 0x5800, 0x0800, CRC(7f1d1f44)
ROM_END
Output use in Program ROMs
Out $00 ($2043)
BRITE $02
NO PLANET $08
- $0E
COIN $0F
Out $09 ($21a1)
(ATTRACT) $00
WIND $02-0D
EXPLOSION $10
PLAYER SHOT $20
Out $11 ($21a2)
(ATTRACT) $00
SAUCER $00
-(NO SAUCER) $20
SCREECH $21
ENEMY SHOT $22
STROBE $24
LAMP $28 - Combined Strobe and Lamp $2C
(ATTRACT) LAMP $08
BONUS $30
Out $01 ($21a0)
(ATTRACT) $00
(GAME_ON) $01
CRASH $05
outs
0025:
out $00
$2043
ori $20
0108:
out $00
$2043
-
010f:
out $04
$2047 - ($00 unless flying in space)
-
04b2,4:
out $07
$2098
04bb:
out $00
$2043
0774!
0778:
out $01
$21a0
077c:
out $09
$21a1
0780:
out $11
$21a2