Archive for March, 2009

NSF Replayer : SPC code update

Tuesday, March 31st, 2009

This early morning I started to disassemble the original SPC.BIN that was in the demo released by memblers. It just happened that the faulty file was I just need to make 2 changes that I describe here :

BEFORE : ROR   *       6C 3 NOP 1 
AFTER :  ROR   !*      6C 3 NOP 1

Seems to be a typo …

BEFORE : MOV     *,A     C4 2 NOP 1
         MOV     !*,A    C5 3 NOP 1

AFTER  : MOV     !*,A    C5 3 NOP 1
         MOV     *,A     C4 2 NOP 1

Look again like a typo, just need to swap to the lines…

So not really a big deal, but now I have a SPC source that compile correctly.

I did a bit of code cleanup yesterday and gave the new rom to Tomy and this time it seems to work. I will release a rom for everybody to test either this afternoon or tomorow morning.

++ Lint

NSF Replayer first results.

Monday, March 30th, 2009

On friday I finally got to make the NSF Replayer work. After various general code checking and made some minor corrections, the player wasn’t still working. From there the only thing that wasn’t checked was the SPC code itself (the only source that I got complete). I had then the idea to the SPC code directly from memblers code ( SNES NSF Player (32Mbit) ).

And … it worked totally fine. Then is various difference with the original SPC.BIN and the one I compiled. I will In a near future reverse the original SPC.BIN and rewrite the correct source code so it can be compiled by hand and can be used for any enhancement that might come one day.

My code is working right on most emu that handle the sound correctly. The Snes9x debug version is really awfull, but zsnes and bsnes are doing the job really fine.

Currently the code seems to not work on the SNES itself as reported Tomy from TOTOTEK. I have no real ideas on why the code isn’t working on the actual SNES for the moment. Tomy reported that he see nothing on the screen while running my proff of concept ROM. I need to assemble a new ROM to check on wich routine the SNES hang. I mainly have 3 functions : 2 init ones and 1 for playing the song that need to be called once per VBlank (not needed in VBlank).

I keep you all informed and will release full source as soon as it is working on the hardware.

See ya, Lint

Working back on NSF Replayer

Thursday, March 26th, 2009

Too long again without any post. I’m really sorry about this. Since I have buy our house in october my mind have been a bit somewhere else.

It’s been now 2 weeks that I’m working agin on the port and cleaning of the nsf player for the snes originally made by memblers.  I have made good advancementlately and most of the code is stable now. Still got minor problems with the direct page register when comming back from nes code execution.

So at the moment no sound output yet but get me a couple of weeks and I’m sure everything will run smooth.I will try to keep you updated as soon as possible, and when project it’s I will release a packeged version of the source code so anyone will be able to use it.

See ya, Lint