I need a piece of code...

[IvanDSM]

Could someone send me a piece of code that would read the A button and then change to a nametable called "ntable1"? I'm using NESICIDE1 as this is my last project on the old NESICIDE. I'm a complete newbie since i don't know a little of assembly!

[unregistered]

Did you mean to ask for code that makes the switch to use nametable "ntable1" as soon as someone presses the A button?

[IvanDSM]

Yes, that's it! I'm trying to make a demo...

[Dwedit]

Would be something like this:

jsr ReadJoyPad1
lda joypad1
and #A_BUTTON
beq +
lda #$80
sta wantNameTable1
+
...

;Somewhere in your NMI handler:

lda PPUSTAT
bit wantNameTable1
bpl +
lda #$10
bne ++
+
lda #$00
++
sta PPUADDR
lda #$00
sta PPUADDR
sta PPUSCROLL
sta PPUSCROLL

Fill in the blanks, provide your own ReadJoyPad1 routine, and equate for A_BUTTON, and equates for PPUSTAT (2002), PPUADDR (2006).

[unregistered]

This code will read all of your controller's buttons and store each one of them in a byte called currControllerButtons.

Code: Select all

ldx #$08
-Loop:
lda $4016
and #$03
cmp #$01

rol currControllerButtons
dex
bne -Loop

Next, this code should help you to know if the A button was just pressed.

Code: Select all

lda currControllerButtons
and #$80
beq abuttonNotPressed

 ; we're here because the A button was just pressed


abuttonNotPressed:

I could explain this code more if you would like that.
Hopefully one of the experienced programmers here could help you with the code that chooses your nametable.

[IvanDSM]

Guys, you are my heroes! Also, i would like to ask: Any tip how i can learn assembler?

Also, what software do you guys recommend for compiling the games?

[booker]

ASM6 for a "simple" but flexible assembler. The next logical suggestion is ca65. I haven't really used that one though.

[IvanDSM]

I'm trying to learn ASM by trial and error with NESASM. I used Famitracker to make a rendition of Yellow Submarine (very bad rendition, by the way ), and exported as a .bin file, how i use it on my code now?

[Shiru]

Using music from FamiTracker in a program is not very suitable task for a beginner.

The simplest way is probably just to use NSF, as I did in NY2011 intro. You need to know where to load it, which addresses you need to call and which memory location it uses - you can learn that from export log, with NSF Tool, and with NSF format doc. In NESASM it will look like this:

Code: Select all

  ;in beginning you need to init music

 lda #0
 jsr $ac00 ;this is init routine in NSF

 ;then you need to update sound every TV frame by calling player

 jsr $ac03
 
 ;here you include your NSF file in your code as binary, complete with headers etc

 .bank 1
 .org $a2e2-$80
 .incbin "music.nsf"

In this example player uses first 18 bytes of zero page and $01f6..$02ed (as reported by NSF Tool).


Other way (that involves the bin you have) would require to adapt source code of FamiTracker to your assembler first.