I'm toying around with Metroid. Looking to create a split screen to include an info bar at the bottom of the screen. I've converted the rom to mmc5, and I have the irq split displaying at the spot I want it to.
Here is a very small preview of my issue.
https://www.dropbox.com/s/sz4xwrkcgpgoy ... t.avi?dl=0
What happens is, the non split area (above my irq, the normal part of the screen) fluctuates when multiple sprites are going on. I'm so friggin close to having this perfect, but idk what else I could be missing or need disabled?
This is my code...
I hope this makes sense, and that there's a solution. Thanks for watching and reading, and any advice to lead me into the right direction.
Here is a very small preview of my issue.
https://www.dropbox.com/s/sz4xwrkcgpgoy ... t.avi?dl=0
What happens is, the non split area (above my irq, the normal part of the screen) fluctuates when multiple sprites are going on. I'm so friggin close to having this perfect, but idk what else I could be missing or need disabled?
This is my code...
Code:
CLI Within Reset Vectors Infinite Loop
CLI
JMP $C0CB. ;reset vector infinite loop
NMI Routine
PHP
PHA
TXA
PHA
TYS
PHA
LDA $#C0. ;vertical position for irq split
STA $5203
LDA $5204
LDA $#80
STA $5204
CLI
JMP $C0DF. ;continue on with NMI
IRQ Routine
PHA
TXA
PHA
TYA
PHA
LDA $5204
LDA #$00
LDY #$00
STY $2006
STA $2006
LDA $FF
ORA #$01
STA $2000
LDA #$00
STA $2005
STA $2005
LDA $5204
PLA
TAY
PLA
TAX
PLA
RTI
Set $4017 to C0 within rom prep at boot
LDA #$C0
STA $4017
CLI
JMP $C0CB. ;reset vector infinite loop
NMI Routine
PHP
PHA
TXA
PHA
TYS
PHA
LDA $#C0. ;vertical position for irq split
STA $5203
LDA $5204
LDA $#80
STA $5204
CLI
JMP $C0DF. ;continue on with NMI
IRQ Routine
PHA
TXA
PHA
TYA
PHA
LDA $5204
LDA #$00
LDY #$00
STY $2006
STA $2006
LDA $FF
ORA #$01
STA $2000
LDA #$00
STA $2005
STA $2005
LDA $5204
PLA
TAY
PLA
TAX
PLA
RTI
Set $4017 to C0 within rom prep at boot
LDA #$C0
STA $4017
I hope this makes sense, and that there's a solution. Thanks for watching and reading, and any advice to lead me into the right direction.