Any scripts/tools to turn on Paula's AM/FM Channel Modulation?

[Paulee_Bow]

Hi folks

This is my first post. After 20 years away from Amiga I bought an A500+ and have done the full works on it, HC533, Kick3.1, CF Hard Drive, 2Meg Chip, 8Meg fast etc.

As well as the odd bit of Whdload I bought the Amiga for musical duties, and have not been disappointed, there's some great applications that make very interesting sounds. I own 30+ synthesizers so you might say I'm a bit of a fanatic!

Anyhow, one niggle I have is that I haven't found anything to turn on Paula's AM/FM channel modulation. A lot of the trackers (like Star Trekker etc) don't use channel modulation to get AM/FM effects but software modulations that keep it on one channel, and they're also kinda tame, I want nasty nasty clangy sounds.

Yes, Soundtracker 1-4 work, but they're bare bones Kickstart 1.2 only, they crash otherwise. Though I am toying with getting a stock A500 to use for these sounds, I'd like a way of enabling this on my A500+

I'm seeking out all the trackers I can find, and I tried to type up an old GFA Basic program that turned on the right ADKCON registers, but it sadly didn't work.

I have seen an assembler tutorial that can accomplish this so I will probably experiment with it in the next few days, but I'd love it if something already existed, you know.

1. Program some sounds in tracker,
2. Click on the magical AM/FM binary file,
3. All hell breaks loose, fun Industrial times.

Any help would be appreciated.

Paul Alex Bow.

[daxb]

Originally Posted by xanderbeanz

Yes, Soundtracker 1-4 work, but they're bare bones Kickstart 1.2 only, they crash otherwise. Though I am toying with getting a stock A500 to use for these sounds, I'd like a way of enabling this on my A500+

Have you tried to softkick ROM 1.2 and then launch Soundtracker? This might be a solution.

[Paulee_Bow]

Originally Posted by daxb

Have you tried to softkick ROM 1.2 and then launch Soundtracker? This might be a solution.

Hi, thanks for your suggestion.
Unfortunately that doesn’t work for two reasons:

1. The program still gives guru errors, as it thinks there is a virus in memory, which is actually the softkick.
2. Soundtracker expects cycle accurate operation from a standard 68000 processor, and sadly my HC533 doesn’t have options to slow it down. I know that there are CPU degraders, but that takes me back to point 1.

Hence, I might have to buy a cheap A500. Heck, they’ll look nice together, like twins. It is a shame though, I would love to have AM/FM options available on my A500+.

[Paulee_Bow]

Something I forget to mention.

What I will say is, I’m going to try and copy the assembler code into Asm2 today and see if I can get it to run. If it works I’ll attempt to compile it and host it in the zone.

I’m very new to assembler though so I’ll have to try and blag my way through.

[Paulee_Bow]

LOL been coding in basic and assembler today but all my attempts crash the system if I run the script whilst a module is playing. Maybe this can’t be done!

[Leffmann]

The AM/FM modulation in Amiga is terribly useless, but you can f.ex. try something like this:

FM_NONE = 128
FM_23   = 64   ; channel 2 modulates channel 3 period
FM_12   = 32   ;         1                   2
FM_01   = 16   ;         0                   1

AM_NONE = 8
AM_23   = 4    ; channel 2 modulates channel 3 volume
AM_12   = 2    ;         1                   2
AM_01   = 1    ;         0                   1

move.w  #$ff, $dff09e
move.w  #$8000|AM_NONE|FM_01, $dff09e
moveq   #0, d0
rts

Check out the AHX and MusicLine trackers, they can do real-time synthesis IIRC.

[Paulee_Bow]

Originally Posted by Leffmann

The AM/FM modulation in Amiga is terribly useless, but you can f.ex. try something like this:

FM_NONE = 128
FM_23   = 64   ; channel 2 modulates channel 3 period
FM_12   = 32   ;         1                   2
FM_01   = 16   ;         0                   1

AM_NONE = 8
AM_23   = 4    ; channel 2 modulates channel 3 volume
AM_12   = 2    ;         1                   2
AM_01   = 1    ;         0                   1

move.w  #$ff, $dff09e
move.w  #$8000|AM_NONE|FM_01, $dff09e
moveq   #0, d0
rts

Check out the AHX and MusicLine trackers, they can do real-time synthesis IIRC.

Yeah I have both of those, they do really cool stuff, I just love audiorate modulation, I know no one probably else into Amiga would use it, but synthesists (especially of the Modular kind) just love this kinda stuff.

Thanks for the code. Which program should I use to input it? Will Asmtwo suffice?

[Leffmann]

Yeah AsmTwo will work fine.

[Paulee_Bow]

Originally Posted by Leffmann

Yeah AsmTwo will work fine.

Thanks, I am stuck at the first line. I type it in and Asm2 tells me

**Undefined symbol

Any help you could send my way would be great. I have no assembler knowledge, or any computer programming knowledge at all really, I am a musician/sound designer/synthesist.

But I’d like to learn.

[Paulee_Bow]

Originally Posted by Leffmann

Yeah AsmTwo will work fine.

Please ignore my previous post. I got Asmtwo working, I was on the wrong page.

I have one last issue.

move.w #$ff, $dff09e

Returned an “illegal operator” error. Any ideas? Thanks

[Don_Adan]

Originally Posted by xanderbeanz

Please ignore my previous post. I got Asmtwo working, I was on the wrong page.

I have one last issue.

move.w #$ff, $dff09e

Returned an “illegal operator” error. Any ideas? Thanks

Try this, without space, before $dff09e register

move.w #$ff,$dff09e
same for

move.w #$8000|AM_NONE|FM_01,$dff09e

[Paulee_Bow]

Thanks, same error, that didn’t help.
Perhaps a different assembler would work?

Thanks everyone for helping me to get my hands dirty with code.
I’m terrified but it’s fun.

[Don_Adan]

Originally Posted by xanderbeanz

Thanks, same error, that didn’t help.
Perhaps a different assembler would work?

Thanks everyone for helping me to get my hands dirty with code.
I’m terrified but it’s fun.

Type manually line by line and check or try to replace "|" with " !", some assemblers like AsmOne dont handle like "|" sign in asm code.

[Paulee_Bow]

The second assembler I tried, Devpac doesn’t like it either. It doesn’t even like move.w even that’s an “error” as are the hash symbols for some reason.

I’ve tried going line by line but it’s hard when you don’t understand the language and the assemblers don’t seem to like anything.

I will happily pay a decent amount (we can haggle it out) to anyone who can write me some code like this and get it to work. This is not my skill set area.

Ideally I’d like a couple of workbench icons, one turning on AM, channel 0&1, one turning on FM, and one turning everything off. Ideally I’d run one of them just before launching pro-tracker.

If anyone’s interested, hit me up in PM.

[Don_Adan]

Originally Posted by xanderbeanz

The second assembler I tried, Devpac doesn’t like it either. It doesn’t even like move.w even that’s an “error” as are the hash symbols for some reason.

I’ve tried going line by line but it’s hard when you don’t understand the language and the assemblers don’t seem to like anything.

I will happily pay a decent amount (we can haggle it out) to anyone who can write me some code like this and get it to work. This is not my skill set area.

Ideally I’d like a couple of workbench icons, one turning on AM, channel 0&1, one turning on FM, and one turning everything off. Ideally I’d run one of them just before launching pro-tracker.

If anyone’s interested, hit me up in PM.

Every assembler line must be started with space sign or TAB.
"move.w" is bad
" move.w" is ok

seems html forced display to no space version.

[Leffmann]

Indent the four lines of code and it should assemble. The equates must be at the beginning of the line.

[Paulee_Bow]

Ooooh! That’s something to try.
Ok I’ll do that tomorrow.

I guess it was just an internet HTML thing.
I’ve learned a lot tonight, thank you for being patient with me.

[Paulee_Bow]

Yay I got it working

Putting in the spaces and the ! marks made it work. I had Octamed running at the time and it all of sudden got as trashy as f***!

I shall experiment more later. It is difficult to get musical results using audio rate modulation processes, but when you do get a good result, it sounds like nothing else!

[Paulee_Bow]

Originally Posted by Leffmann

Indent the four lines of code and it should assemble. The equates must be at the beginning of the line.

I’ve found good usage for this modulation now

Using - sequence of high frequency notes to modulate a drum channel gives some really cool effects.

2 little issues:

- Firstly, As a complied binary, clicking the binary’s icon on workbench does turn the modulation on, but pops up with an error message, suspend and reboot. Suspending gets rid of the window, but I’d like to get rid of the error. Is there a line I can add to make the system happier?
- Also, I seem to lose channel 3 (actually the 4th channel as it goes 0, 1, 2, 3) with this code. Any ideas on how to make this not happen?

Thanks! It’s no biggie if these can’t be sorted as I’m using the Amiga along with other synthesizers and don’t need lots of channels.

[meynaf]

Originally Posted by xanderbeanz

- Firstly, As a complied binary, clicking the binary’s icon on workbench does turn the modulation on, but pops up with an error message, suspend and reboot. Suspending gets rid of the window, but I’d like to get rid of the error. Is there a line I can add to make the system happier?

I guess the error is 87000004 ?
Several solutions exist :
- Don't give it an icon but use the pseudo-icon (with "view all files" option).
- Use IconX.
- Add proper WBStartup code to the program.

Originally Posted by xanderbeanz

- Also, I seem to lose channel 3 (actually the 4th channel as it goes 0, 1, 2, 3) with this code. Any ideas on how to make this not happen?

As the principle of this synth method is to use the output of some channels to modulate others, it's normal you lose channels in the process.