Nyan cat

ElBarto · Post by **ElBarto** » Sat Aug 20, 2011 9:47 am

Cause the megadrive must have it's nyan cat demo

http://megadrive.org/~elbarto/md/nyanmd.bin

If someone want to compose the music let me know I'll add it.

bastien · Post by **bastien** » Sat Aug 20, 2011 9:59 am

haha nice

maybe you can it with PCM sound ?

ElBarto · Post by **ElBarto** » Sat Aug 20, 2011 1:46 pm

I've added pcm sound with Chilly Willy/Tidoo T-ADPCM driver.
It works on MESS (but freeze for 1/2 sec some times) but not on Kega so it will probably fail on HW.
http://megadrive.org/~elbarto/md/nyanmd_sound.bin

sega16 · Post by **sega16** » Sat Aug 20, 2011 2:53 pm

Edit:No sound thank god.
I hope it is not that song that song with 2 new notes that just keeps looping while some toaster and a rainbow cat looking thing flies.Anyways why don't you try my rick roll demo which pretends to be a sonic hack while your at it.
http://depositfiles.com/files/oiphdq8dy

bastien · Post by **bastien** » Sat Aug 20, 2011 4:04 pm

i tested it with gens and not have any sound.
Maybe you should use ADPCM driver with SGDK for having sound , i never have a problem with it and seems always works in RH.

Did you use SGDK for making it ?

Chilly Willy · Post by **Chilly Willy** » Sat Aug 20, 2011 7:48 pm

My experimental drivers work on Fusion, Gens, Gens_GS, and real hardware without issue. He probably just "goofed" something simple when trying to work it into his program.

Eke · Post by **Eke** » Sun Aug 21, 2011 11:07 am

I got sound in genesis plus too, the problem is that your code make use of an undocumented feature of YM2612 (only recently found by Nemesis).

Here is what I logged in my emulator:

Code: Select all

FM port 2 write $B6 (000008DC)
FM port 0 write $2B (000008DC)
FM port 1 write $80 (000008DC)
FM port 0 write $2A (000008DC)
FM port 1 write $80 (000008DC)

then later

Code: Select all

FM port 3 write $02 (00000DA8)

What happen in Kega/Gens is that they use two separate address registers for writes to FM ports 0 and ports 2, so when port 3 is written, $02 will be written to $B6 register, thus disabling channel 6 output !

On real hardware (and more accurate emulators), address port is shared so the first write to FM port 2 is made useless by the next write to FM port 0 and the first writes to FM port 3 goes to DAC register ($2A) instead.

Chilly Willy · Post by **Chilly Willy** » Sun Aug 21, 2011 7:36 pm

Yeah, the driver is based on the old PCM drivers from the mini SDK in how they write the YM2612. They work on CURRENT emulators and real hardware, but that "bug" should be fixed. The issue you mention was only (relatively) recently discovered and mentioned in the YM2612 thread.

EDIT: One not well documented limitation of my TADPCM driver - the data MUST be longword aligned, otherwise you just get noise.