SoundTracker for ZX81 ?

[sirmorris]

You know you can set RAMTOP from within your code without a reset? See the new post!

Also CONFIG "M=H" will work as the 1st line of your code.

[Andy Rea]

I'll stick the "M=H" line in the basic then, however the ramtop routine is not good for me, so have wrote my own that copies the entire stack to the new location

Andy

[sirmorris]

Thinking about it - if this is run on a machine without zxpand, then you'll get LLIST "M=H" which will cause an error.

I've knocked up some code to do what you need which can be safely run on non-zxpanded machines (perish the thought ;¬) and mailed it to you.

C

[Andy Rea]

Thanks Charlie, mail recieved, and works beautifully, but then we all expect that of the great Sir Morris

Andy

[sirmorris]

/me bows

[Moggy]

Crawler

[Moggy]

@Andy

I think I've found a bug

Using an ordinary sample call it No 1 build up a pattern as normal in say channel A You end up with something like this..

A
000 C 4 1000

Ok so far so good now lets say We want to experiment with the envelope control and end up with this..

A
000 C 4 1C2B


A simple envelope sound which, for the sake of this example the values are irrelevant, will switch on envelope C with the values 2B.
If it's decided that the sound isn't suitable and You want to revert back to original values IE..
A
000 C 4 1000

Then for some reason the channel stays silent from then on as if switching the envelope off also reduces the channel volume to 0, the only way I have found to regain normal volume again is a complete reset.

I haven't restricted this to one note as per example, in practise the whole track remains silent unless reset.

Not a criticism Andy just pointing out bugs like You asked.


Regards.
Moggy

[Andy Rea]

Hmmm interesting, I'll take a look at it when i get 5 minutes.

but for now, what happens if you change the 'C2B' for 'F00' ?

whilst in the editor it's a bit tricky to determine exactly what sample / ornament / effect to use based on a single line, as your aware the values after the note if set to zero mean used the current sample / ornament / effect.

Can you eleaborate on the exact steps took to reproduce this behaviour ?

regards Andy

[Moggy]

@Andy


Right create a sample (1) then place this note in the tracker (any will do)

A
000 C 4 1000


The note will sound as it should do.


Alter note to this..

A
000 C 4 1C2B (the values are irrelevant You are only selecting an envelope of a given frequency)


It will also sound as it should do.


but reverting back to this.


A
000 C 4 1000 silences the channel as opposed to playing the original sample.



Starting from scratch switching in an ornament like this.


A
000 C 4 1F0N (N being any ornament 1 to F created)



Sounds as it should.


Reverting back to this.



A
000 C 4 1000


Also sounds as it should.


The problem lies in switching envelope sounds in and out, once switched on You're stuck with them as switching them off silences the channel for normal note use but oddly enough allows You to revert back to the envelope sound.



This is a clear as I can make it Andy hope it helps


Regards.
Moggy

[Moggy]

@Andy


Further to last post I have found a crude workaround .

The channel that is now silent after switching off the envelope and now looks like this.


A
000 C 4 1000


Can be restored by temporarily altering to this.


A
000 C 4 1F00


Then back to this.


A
000 C 4 1000

This wont work in the context of a composition because slapping in an ornament message just to restore normal channel/sample volume is not right and will cause that ornament to sound also.

Envelopes should switch back and forth as needed just by zeroing the three columns after the sample to 000 thus restoring the original sample/volume.
Switching between ornaments and original sample no problem but switching between envelope and back to original sample brings silence instead of restoring original sample/volume.


Hopefully this may point to where the problem lies.


Regards.
Moggy