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Oh that's interesting.

I just have a feeling I'm missing something, still can't figure it out why they don't work.

I'm using fceux 2.2.1. I got alot of help/assistance from users here, in getting my custom mmc5 irq to fire up. in my Zelda hack, I have 2 separate irq sequences, and they work perfectly within fceux. Now someone tested my rom on an etrom board, and one of my irq sequences wouldn't fire up. I then l...

Yes thats how zelda does it.

Highppu
Lowppu
# of tiles (02 for example)
tile
tile
FF (end) (unless theres more going on, then this would be the start of another highppu address)

Thank you both for the detailed resposes.

Im assuming this is called vram buffering. Anyway, my rom hack of The Legend of Zelda, i inserted a working 2 digit counter for Links arrows. The vran starts at $302, and its constantly updates Links heart count, rupees,bombs, & keys counts. I was able to insert my custom counter at the end of w...

Many thanks!

How would I go about creating a very simplistic random number generator, with values in the register in the range from 01-04?

Thank you.

Ok thank you. Ill try to figure out the origin of the game logic, and try to relocate within the reset vector.

The code was taken from an old megaman project of mine. Looks ugly, yes, but it xan be written better like you suggested. I do have one more question, non irq related. I have signifigant slowdown when i have more than 3 active sprites. By active, i mean it has asm that controls its AI, x/y, etc. The...

@ tokomaru, you are right. I removed the PHP & PLP's and I still have proper irq usage going on.
@ rainwarrior, i'll add your suggestions and see what happens.

The routine that I discovered works a better when projectiles are thrown, I experience no flickering/shaking with the irq. However with your routine, I get that slightly with projectiles. I went to the same screen id with the same enemies, and tested both routines, and those are the results I got. I...

Did you see my previous post?

I figured it was ok... LDA $5204 LDA #$20 LDY #$00 STY $2006 STA $2006 LDA $FF ORA #$01 STA $2000 LDA #$00 STA $2005 STA $2005 LDA #$3F STA $5203 RTI I just tried adding the push registers before my irq engine, and then pull my registers at the end of my irq engine, and still got the same result. ED...

I do not know how to determine the scanline. All I know is I have the split to appear just below the info bar in the game. Loading 3F and storing it into $5203 sets the vertical position below the info bar. I don't know how to pin-point snap the debugger to see if the scanline column actualy registe...

This so confusing. So I put back the CLI in my reset vector. Now within my NMI, when I'm about to use a CLI, your saying I need to acknowledge and enable the irq device before I use the CLI? To acknowledge it within mmc5, do I just simply use an LDA of $5204? do I write to $5204? You say to disable ...