2000 PPUCTRL
2001 PPUMASK
2002 PPUSTATUS
2003 OAMADDR
2004 OAMDATA
2005 PPUSCROLL
2006 PPUADDR
2007 PPUDATA
4000 SQ1_VOL
4001 SQ1_SWEEP
4002 SQ1_LO
4003 SQ1_HI
4004 SQ2_VOL
4005 SQ2_SWEEP
4006 SQ2_LO
4007 SQ2_HI
4008 TRI_LINEAR1
4009 TRI_LINEAR2
400A TRI_LO
400B TRI_HI
400C NOISE_VOL
400E NOISE_LO
400F NOISE_HI
4010 DMC_FREQ
4011 DMC_RAW
4012 DMC_START
4013 DMC_LEN
4014 OAM_DMA
4015 SND_CHN
4016 JOY1
4017 JOY2
