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VRCVII / VRC7 Sound Registers

VRCVII / VRC7 Sound Registers
by on (#38643)
http://kevtris.org/nes/vrcvii.txt

I have problem with VRC7 sound registers,
kevtris write:

All sound registers are accessed through only two physical registers.
9010:
-----
This is the index register. You write the desired register number here.
9030:
-----
This is the data register. Data written here is stored in the register
pointed to by the above index register.

ok... but

00h - 07h : Custom instrument registers -> This mean $9000-$9007 ?????

10h - 15h : ffffffff -> mean $9010 - $9015 ???

30h - 35h : iiiivvvv -> $9030-$9035 ???

I can't understand this :)

by on (#38645)
Should be simple enough. You set the index, then writes to the data port go to whatever you set the index to.

by on (#38648)
Quote:
00h - 07h : Custom instrument registers -> This mean $9000-$9007 ?????

10h - 15h : ffffffff -> mean $9010 - $9015 ???

30h - 35h : iiiivvvv -> $9030-$9035 ???


No, you got it wrong.

This is how you do it, at least according to Kevtris' description:

lda #$07
sta $9010
lda #$AA
sta $9030

writes $AA to register $07.

by on (#38649)
ok. thanks :)