Complete Build Environment CA65 Basic MMC3 Cartridge With Test Code
1. PRG Rom Bank Switching
2. IRQ Scan Line Trigger
3. CHR Sprite Changes 2x2k and 4x1k
This is just an entry level MMC3 assembly code/setup to show you how to setup MMC3
But this can lead to create depth of field (Parallax) and dual area's
https://github.com/Atomfusion1/NES_MMC3_CA65_Demo_Cart
I have been spending a week trying to program an NES cartridge,
I find it far harder than it should be, One everyone tells you to go learn from Nerdy Nights but then tell you not to program in nesasm but ca65 deals with memory segments differently. Many people post Asm code without saying what assemble to use and on top don't even put in the .nes file to see if its worth your time etc.
This Tutorial File I'm working on Working Sound and effects, Weapon, Sprites, Background, Scrolling (no collision or many other things)
Most tutorials seem to fall into two types, One they are two simple and there is not enough of anything there to be useful/good starting point, or two so far advanced that its useless to a beginner. (rant over)
This Tutorial File I'm working on Working Sound and effects, Weapon, Sprites, Background, Scrolling (no collision or many other things) Feel free to test it out, its not optimal but my goal is to make it readable / easy to follow in order to use everything to make your own game level / start out, This can at least give you a quick feeling of how far down the rabbit hole you want to go.
I am looking for a little help with CA65 CFG file and mappers MMC1 and MMC4
I have spent about 8 Hours messing with nes.cfg in order to get 4 selectable CHR locations
This Cfg file will let you build NROM(0), CNROM(3), MMC1(1), MMC3(4) but only up to 32 Prog Rom and 32 Chr rom I would like to get a 128x128 MMC1 and a full layout of MMC.
What I would like:
1. Simple NROM(0), CNROM(3), MMC1(1), MMC3(4) cfg files .
2. if its not much trouble for you, a snippet of how to change banks / prog pages .
Code: Select all
SYMBOLS {
__STACKSIZE__: type = weak, value = $0300; # 3 pages stack
}
# Full Config for MMC3
MEMORY {
# First 28 bytes of the zero page are used by NES library
ZP: start = $10, size = $FD, type = rw, define = yes;
# INES Cartridge Header
HEADER: start = $0, size = $10, file = %O ,fill = yes;
# 2 16K ROM Banks
# - startup
# - code
# - rodata
# - data (load)
# NROM256
PRG: start = $8000, size = $7ffa, file = %O ,fill = yes, define = yes;
# Hardware Vectors at end of the ROM
# NROM256
VECTORS: start = $fffa, size = $6, file = %O, fill = yes;
# 4 8K CHR Bank
CHR: start = $0000, size = $8000, file = %O, fill = yes;
# standard 2K SRAM (-zeropage)
# $0100 famitone, palette, cpu stack
# $0200 oam buffer
# $0300..$800 ca65 stack
#RAM: start = $0300, size = $0500, define = yes;
# Use this definition instead if you going to use extra 8K RAM
RAM: start = $6000, size = $2000, define = yes;
}
SEGMENTS {
HEADER: load = HEADER, type = ro;
STARTUP: load = PRG, type = ro, define = yes;
LOWCODE: load = PRG, type = ro, optional = yes;
INIT: load = PRG, type = ro, define = yes, optional = yes;
CODE: load = PRG, type = ro, define = yes;
RODATA: load = PRG, type = ro, define = yes;
DATA: load = PRG, run = RAM, type = rw, define = yes;
VECTORS: load = VECTORS, type = rw;
CHARS: load = CHR, type = rw;
BSS: load = RAM, type = bss, define = yes;
HEAP: load = RAM, type = bss, optional = yes;
ZEROPAGE: load = ZP, type = zp;
}
FEATURES {
CONDES: type = constructor,
label = __CONSTRUCTOR_TABLE__,
count = __CONSTRUCTOR_COUNT__,
segment = ONCE;
CONDES: type = destructor,
label = __DESTRUCTOR_TABLE__,
count = __DESTRUCTOR_COUNT__,
segment = RODATA;
CONDES: type = interruptor,
label = __INTERRUPTOR_TABLE__,
count = __INTERRUPTOR_COUNT__,
segment = RODATA,
import = __CALLIRQ__;
}