Just letting you know that I got the 16 bit counter working. The reason why it looked like it didn't, was that I had the PPU turned on when I drew the background. Anyway, thanks for the help. I'm off to learn how to use NMI and VBlank.

You can directly INC or DEC a memory location without using a register.

Replace:

LDA pointerLo
CLC
ADC #$01
STA pointerLo


with:


INC pointerlo


But anyway, here is a suggested way of doing things that is simple.. if you make sure your data is a multiple of 4 bytes (4 bytes of data, 8 ...

I almost got it working. This is what I used:

DrawBackground: ; Loop for drawing background
LDA #$B3
STA pointerLo
LDA #$80
STA pointerHi
LDA #$00
STA counterLo
LDA #$04
STA counterHi

BgLoop:
LDA [pointerLo], y
STA $2007
LDA pointerLo
CLC
ADC #$01
STA pointerLo
LDA pointerHi
ADC ...

That suggests the assembler you're using doesn't like/understand standard 6502 syntax. What assembler are you using?

I'm using NESASM3.

EIDT: Also there is some weird issue that I forgot to mention that started around the time I started doing the 16 Bit counter stuff. It happens whenever I ...

Okay. I tried this code (I of course edited the pointer names and labels to fit in my program), but I got few syntax errors (marked red in the code)


...
DrawBackground:
lda #<background ; init background pointer
sta zppointer
lda #>background
sta zppointer+1
ldy #0
DrawLoop: ; transfer 3 ...

You can squeeze a few cycles (and one byte!) using X to count the pages
It shouldn't matter where the data for the background is. The assembler will work out the actual address and use it in the <background and >background expressions used to initialise the pointer.

So, using the < and > with a ...

One way to do it is to put the address of "background" into a pair of ZP bytes

How do I know where the background is in the program?

The way I learned to load the background is doing this (not sure if this is how everybody does it):

background:
.db $2F,$2F,$2F,$2F,$2F,$2F,$2F,$2F,$2F,$2F,$2F ...

So, I'm trying to make a loop that counts to 960 (decimal), but I have never used 16 bit numbers so far, so I have no idea how to do it. What the loop is supposed to do is that it loads data from different location with indexed X addressing mode and stores it to $2007 (which automatically stores the ...

So, I think I now have all that I need to actually make some code, but I can't find a reference code (for NES) anywhere. I know some of the stuff I need to add to the code, but I don't know the overall code structure. Can someone make a short code that has everything that is needed (iNES header ...

I'm so confused with ADC, SBC, Carry Flag and Overflow Flag that I need some help. I tried looking many places for these, but the information is either unclear, confusing or the information on the sites might differ so greatly that I don't know which one to believe.

Few more questions:
1. What's the difference between the accumulator (A) register and the indexing function (X and Y) registers (in what kind of situations they are used)?
2. What are the S and P registers and the stack used?
3. How is the Memory are divided for specific actions (like drawing ...

Every guide about 6502 assembly talks about things called A, X and Y, but none of them explain what they are, where they are used, etc. It's odd that in the very beginning parts these are introduced but never explained.