Another question of the Moonblaster file format

By jepmsx

Master (130)

Аватар пользователя jepmsx

11-02-2022, 10:05

Hi!

I've been tinkering with the moonblaster file and I've got another question. In the file format specification (https://www.msx.org/wiki/Moonblaster_file_format) there is the pattern data 218-223 (Brightness negative) and 231-236 (Brightness positive). I don't know what this Brightness does.

I've checked the manual (https://mus.msx.click/index.php?title=TRACKERS_MOONBLASTER_E...) and the moonsound version (https://download.file-hunter.com/Manuals/Moonblaster%20for%2...) and I haven't been able to find any reference on what brightness is and how to input in the editor.

Any help is welcome

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By Grauw

Ascended (10581)

Аватар пользователя Grauw

11-02-2022, 10:30

Brightness refers to controlling the level of the modulator on the fly.

I believe the command in the editor is X ± 1-6.

By meits

Scribe (6500)

Аватар пользователя meits

11-02-2022, 10:38

Grauw wrote:

Brightness refers to controlling the level of the modulator on the fly.

I believe the command in the editor is X ± 1-6.

You're correct.

By ro

Scribe (4698)

Аватар пользователя ro

11-02-2022, 11:40

hey, that's funny. I was curious and followed the link to the wiki with the MB file format. I looked at it and thought, wow that looks like something I could've whipped up. I looked up my old docs; yup I wrote that looooooong ago Smile

[/offtopic]

By jepmsx

Master (130)

Аватар пользователя jepmsx

11-02-2022, 18:19

Thank you guys. I'll try it!

By jepmsx

Master (130)

Аватар пользователя jepmsx

12-02-2022, 07:26

I've tried it. And the X command is accepted and performed in MSX-Audio. I've enabled only the MSX-Music and there is no effect. So I'm assuming it's only MSX-Audio/Moonsound.

By the way ro, Moonblaster has so many options that documentation would have been hard. It's only a small piece, the rest is very well explained. Thanks for the great work you did!

By ro

Scribe (4698)

Аватар пользователя ro

12-02-2022, 09:27

Hai, the X effect only works on original instrument. For fm there is only one channel at the time for that.

By jepmsx

Master (130)

Аватар пользователя jepmsx

12-02-2022, 10:33

Yes, you are totally right. I've changed the hardware voice for Strings 1 provided by Moonblaster and the effect is done.

Thanks!!

By jepmsx

Master (130)

Аватар пользователя jepmsx

17-02-2022, 23:02

I still don't understand what brightness should do.

I've created this easy song in Moonblaster and created a vgm file using openMSX and converting it to text using vgm2text to see what the chip is doing.

I can see that it writes in register 0x02, but I can't guess the value to write depending on the command.

I've checked what roboplay does (void brightness_positive_event) and it adds to the read value of the file its value &0x3F and again but now &0xC0. But I fail to see why.

Can someone shed some light?

By wolf_

Ambassador_ (9956)

Аватар пользователя wolf_

17-02-2022, 23:30

Brightness is just the level of the modulator. The modulator modulates the carrier, thus adding harmonics. It's kind of like a low-pass filter, but not really.

By jepmsx

Master (130)

Аватар пользователя jepmsx

18-02-2022, 09:38

Thanks wolf_ for the answer.

It makes sense because register 0x02 is the modulator value.

Now I'd like to know when I set X+1 in moonblaster it increases the value of the modulator by 1?