music in NMI - NESdev BBS

music in NMI
by hd380000 on 2009-05-16 (#46868)

Sometimes why do I put music procedure to nmi in the screen demonstrate glitter, sometimes beats?

Code:

nmi:

    pha
    txa
    pha
    tya
    pha
    php

          lda #$00
     sta $2003
     lda #$02
     sta $4014
     jsr joy1p
    
    lda <scrollx
    sta $2005
    lda <scrolly
    sta $2005
    lda <vhi
    sta $2006
    lda <vlo
    sta $2006
    
    jsr music 
nmi000:    
    pla
    tay
    pla
    tax
    pla
    plp
    rti

by Dwedit on 2009-05-16 (#46869)

Read from the joystick AFTER you're done with everything on the screen, not before.

by hd380000 on 2009-05-16 (#46871)

Code:

nmi:

pha
txa
pha
tya
pha
php

jsr joy1p :First it does then under do other thing ,is thet righr?

lda #$00
sta $2003
lda #$02
sta $4014

jsr music
nmi000:
pla
tay
pla
tax
pla
plp
rti

I such understand Dwedit words , but I have tried, dodges as before

by tokumaru on 2009-05-16 (#46882)

No, the joystick comes after everything related to graphics. Try putting "jsr joy1p" before or after "jsr music ".

by Memblers on 2009-05-16 (#46885)

The PLP instruction is in the wrong place. If it's the last thing pushed on the stack, it should be the first thing pulled.

Also you can remove both the PHP and PLP in that case because they aren't needed. The NMI automatically pushes the processor status, and RTI restores it.

by hd380000 on 2009-05-17 (#46898)

Here is my files.
http://www.uushare.com/user/hd380000/file/1611206

I have made a change, but has not been able to solve the problem.

by Memblers on 2009-05-17 (#46918)

Using FCEU, Nestopia, Nintendulator, and NESten I only get a blank screen and no sound. Looking at RAM in the debugger, it looks totally uninitialized. You could try clearing RAM, maybe that's messing up the music engine. I don't know if it'll fix it, but it's always a good idea to clear RAM anyways.

I'd change the startup to this:
Code:

CLD
SEI

ldx #$00
stx $2000
stx $2001
dex
txs
inx
txa
@loop:
sta $00,x
sta $200,x
sta $300,x
sta $400,x
sta $500,x
sta $600,x
sta $700,x
inx
bne @loop

Also you'll want to clear VRAM (nametables and such), it won't matter on an emulator though.

by hd380000 on 2009-05-18 (#46953)

If I look at the procedures shown in the time interval lengthened, then the phenomenon of flash will become less, which means that I did not do a good job Vblank Ming, is it?
Nmi is also not a design problem.
And cleanram is a good idea,Although there is no solution to the problem of flash。
Code:
mainloop:
lda <time1
cmp #$01
bne jia
inc <time1
lda #$00
sta $2001
lda <vhi
sta $2006
lda <vlo
sta $2006
jsr vwait_start
lda <tile
sta $2007
inc <vlo
bne jia
inc <tile
inc <vhi
lda <vhi
cmp #$24
bne jia
lda #$20
sta <vhi
jia:
jsr vwait_end
lda #%00011110
sta $2001
jmp mainloop