Monday, March 07, 2005

Almost good enough

I am at a point that I almost consider good enough. The FM part is supported as well. The state machine seems to produce the correct notes, the only strange thing is that the volume is extremely low - I had to push it to 2.0 gain and lower all the others to make it reasonable. There might be a bug somewhere in the way the FM parameters are set - this stuff is much more complex than the PSG.

At this point, I'm more worried about the protection in some games than by the sound, which is coming along nicely.

It has to be said that this simulation I've written was mostly for personal education and for reference. I am 99% certain the the NMK004 internal ROM can be extracted, using a technique I thought of. Theoretically it's very simple, but the process will require some hardware work.

And of course, once the ROM is extracted, we'll have to see if it can be ran in MAME. It supposedly is a TLCS-90, which is one of the few CPUs not yet supported by MAME, so an emulator for that CPU would have to be written. Which would be a good thing because it would also allow to support Mahjong If and sound in Rapid Hero.
Having the simulation code available might help while writing the CPU emulator.

13 comments:

Anonymous said...

IIRC the TLCS-90 is a Z80 binary compatible CPU, so it shouldn't prove hard to write a core for it :)

Keep up the great work!

Anonymous said...

Close - it's a Z80 with more opcodes I think.

Anonymous said...

Just in case it is needed:

http://sus.toshiba.de/SoftwareUpdate/software_pages/tlcs-90.htm

Anonymous said...

In the page quoted below you can download a pdf:

"Appendix B Instruction Lists to Appendix D Differences between TLCS-90 and TLCS-900 Series"

page:

http://www.semicon.toshiba.co.jp/eng/prd/micro/td/900family/900h/95c063/e_95c063.html

can be usefull?

Anonymous said...

Hooray for proper emulation! Hope that chip is dumpable... one less to perfection!

Anonymous said...

Hello nicola, can you please elaborate your idea in howto dump the microcontroller ? , anyway good luke :)

Anonymous said...

BTW, regarding the FM volume, most Yamaha chips have 0 = full volume and 0xff = silent, so maybe you have the scale reversed?

Anonymous said...

That reminds me of that system11 sound chip not dumpable, just trojanable!

Maybe that's something for Nicola's next work.

Anonymous said...

You know, Anonymous,

That reminds me of that system11 sound chip not dumpable, just trojanable!

Maybe that's something for Nicola's next work.

Anonymous said...

Oh, all the double posts are gone. Meaning that Mr. MAME is watching over his blog RIGHT NOW!

*Waves at Nicola*

Ciao a tutti!

Anonymous said...

Yayy! More mahjong! Just what mame needs!!!

Anonymous said...

Nicola you are very smart person. You seem to be a perfectionist who enjoys discovery? Outstanding work indeed. Keep it up!

Anonymous said...

Is it now a time for decypting more Dynax's games between 91~94,e.g. Tenkaigen?
They mostly used the same MCU chips, and these chips are TLCS-90 series.