Outrun - Master System FM Sound version glitch

[the1ross]

This only happens when the sound is set to FM sound.

When you begin the opening stage, there is noticeable audio distortion that can be heard until you crash into another car, after which the game sounds fine.

[theflynn49]

What game do you mean exactly (please insert complete name and crc32 of your image here so I make sure)

In fact Outrun (not Europa) doesn't run. Maybe you mean Outrun Europa ?

[theflynn49]

Forget it.
It does work with MiST and I can hear the problem with the SMS version, not in the GG one.
Seems like the noise generator is not initialized properly and produces sound until it is used in a crash, then it gets stopped.

[theflynn49]

... and if you disable "FM Sound" you don't get the trouble.
and I should have read the title of this issue before commenting lol

[theflynn49]

My problem with OutRun is that most of the ROMs I have begin with garbage :

hexdump -C OutRun\ (UE)\ [b2].sms | head
00000000 10 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00000200 f3 ed 56 31 00 de 18 7c 7b d3 bf 7a d3 bf c9 ff |..V1...|{..z....|

$000 to $1FF is garbage, I guess MiST removes it somehow, but Mister doesn't like this.

note: isn't this supposed to be dealt with in SMS.sv ? whatever.

[the1ross]

Yeah, I thought it might be the ROM but I tried it on Kega Fusion and it worked fine with FM sound.

[sorgelig]

this line is SMS.sv:

.raddr(ioctl_addr[9] ? (ram_addr - 10'd512) & cart_mask512 : ram_addr & cart_mask),

supposed to skip the header if it presents.

[theflynn49]

Yes, I just realized that 2^9=512 ... I was confused yesterday :)
The sources for the YM2413 are pretty abstruse , I didn't catch much at first sight. On another hand, I didn't get the 1-line rom size thing yesterday, so that was not my day to look into those sources I guess ...

Anyway, the fact that the header removal thing doesn't work on MiSTer for OutRun is worrysome, I'll have a look into that.

[SegaSnatcher]

Yes was just going to post this issue. Any updates?

[theflynn49]

I thought I fixed this long ago, maybe I am confused. But I haven't done anything for the audio bug.

[SegaSnatcher]

PSG sounds fine, but the FM bug is still a problem. I.E. White noise until you hit something.

[theflynn49]

This.
As far as I remember, pb is in VM2413, but not much people seem to be working on this module lately. Not much of a SMS pb anyway.

[greyrogue]

#108

[thehughhefner]

Has this issue been fixed? If so then this ticket can be closed