2016.12.23
There are 4 Toaplan games with no sound in MAME 0.180.
These games are Fire Shark, Vimana and Teki Paki and Ghox. The original
Japanese release of Whoopee is lacking in sound too but in that case the
Export version is not.
The reason these lack sound is simple, the chip shown below.
http://mamedev.emulab.it/haze/pics2016/HD647180.jpg
Each of the above games contains one of these chips. The chip is an MCU
containing a Z(1)80 core and various peripherals as well as 16kb of internal
ROM data. That ROM data contains all the sound information for the game, all
the sound effects, all the music sequences, everything; it makes no use of
external data.
Without the internal ROM for each game sound simply can’t be emulated
properly, because there’s nothing to use to emulate it. Due to everything
being squeezed into the internal ROM space there’s no exploit using external
code / data that can be used to dump the roms either as was done for the
NMK004 sound system and a number of others.
As a result, these have been considered ‘holy-grail’ targets by quite a
large number of people. With that said, I present to you the following 3
videos.
https://www.youtube.com/watch?v=IhzRe8uSHcQ
https://www.youtube.com/watch?v=Pc1QpQjtEbo
https://www.youtube.com/watch?v=4LVJdy66XUo
Those videos are all showing proper emulation of the sound, not some ugly
trick using samples from the PCB, but the actual sound code running in MAME,
driving the emulated YM3812 sound chip.
This was made possible by the decapping work done by ‘Team Caps0ff’ who
managed to acquire the various chips that had previously been sent for
decapping, take stock, and resume work on them – identifying weaknesses and
coming up with a solution, in this case clearing the security bit inside the
chip and reading out the data. (They also provided the MCU hookups in the
drivers meaning this ended up being a simple case of sitting back and
enjoying the results)
Ghox and the Japanese Whoopee PCB using this chip have not been done yet
because Caps0ff doesn’t currently have those chips, and has a backlog of
other chips to process, but the method used to dump the ones you see is now
proven and tested and will also work for those once they’ve been acquired.
The Caps0ff blog contains more detailed technical information on the process
used, it’s a fascinating read and shows that these guys really know their
stuff :-) Please check it out and show support if you can.
(and yes, this has been my favourite news of the year to wake up to, hence
giving it a bit of coverage)
http://mamedev.emulab.it/haze/