How to create mapper X ROM

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itoken
Posts: 5
Joined: Mon Jun 21, 2021 12:35 am

How to create mapper X ROM

Post by itoken »

Hi folks,

//I'm newbie

I've created a small game(mapper 0?) with cc65 and stock nes.lib.

Then, I think I want to create other mapper games with expansion audio(FDS, VRC6, ...).
However, where can I get the documents to create other mapper games?

I specified mapper number to image header like the following.
But, can not run properly. Anyone can advise to me?

My tiny program is here.
https://github.com/110-kenichi/mame/tre ... GMPlay_NES

Code: Select all

.define NES_MIRRORING 0 ;   0:Horizontal/1:Vertical/3:Vertical & WRAM Mirror
.define NES_MAPPER 20

.segment    "HEADER_FDS"
    .byte   $4e,    $45,    $53,    $1a ;   "NES" Header
    .byte   2                         ;   PRG-ROMバンク数(16kb x2)
    .byte   1                         ;   CHR-ROMバンク数(8KB x0)
    .byte   NES_MIRRORING|((<NES_MAPPER<<4) & $f0)
	.byte   NES_MAPPER&$f0
    .byte   0                         ;   PRG-RAMサイズ
    .byte   0                          ;$00 = NTSC, $01 = PAL
lidnariq
Posts: 11432
Joined: Sun Apr 13, 2008 11:12 am

Re: How to create mapper X ROM

Post by lidnariq »

FDS games, in particular, must be distributed as a FDS disk image, not as a mapper 20 ROM.
itoken
Posts: 5
Joined: Mon Jun 21, 2021 12:35 am

Re: How to create mapper X ROM

Post by itoken »

lidnariq-san,

Thank you!

Ah.. Could you please tell me how to compile src to FDS image...?
Last edited by itoken on Mon Jun 21, 2021 5:22 pm, edited 1 time in total.
lidnariq
Posts: 11432
Joined: Sun Apr 13, 2008 11:12 am

Re: How to create mapper X ROM

Post by lidnariq »

Rainwarrior has done this a couple times:
https://github.com/bbbradsmith/NES-ca65 ... e/tree/fds (just enough framework to start)
https://github.com/bbbradsmith/NESertGolfing/tree/fds (a full game he's released under CC-BY)
itoken
Posts: 5
Joined: Mon Jun 21, 2021 12:35 am

Re: How to create mapper X ROM

Post by itoken »

Thank you!
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