What CPU overhead can be disabled and how? about ldos

[arnaud-carre]

Yes LDOS is using a 50hz cia timer to handle both music and floppy loading. You swith cia off in your fx. When you quit the fx and go back to ldos, the cia will becsetup again

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On 14 Feb 2024, at 06:14, Jobbo ***@***.***> wrote:  Hi there I have a routine that's extremely close to using a full frame. It can run at 50hz in my own framework while also playing back an LSP tune (without the need for insane mode). However, running it inside LDOS there must be additional overhead as it's going over the limit. Can you fill me in on the additional overhead and what/how I might be able to disable that for the duration of one effect? — Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you are subscribed to this thread.

[rjobling]

At the moment it seems like the music will also stop.

It seems like I need LSP_MusicPlayTick exposed. Then I have two options:
1 - Call LSP_MusicPlayTick every frame.
2 - Replace the CIA handler with a simple one that calls LSP_MusicPlayTick.

A third option is that I add the simple handler on the LDOS side and add a method for telling it to swap to that handler.

I can give those a try, but it seems like there's a good chance I could introduce a music glitch not matter what I do. Of the options replacing the CIA handler seems easiest and most likely to continue without glitching.

[rjobling]

I gave that a try and it seems like it works.
It does save a few cycles, but not really enough to solve my problems.
Using insane player code might be another thing I'll try.

[rjobling]

No need to keep this open.

[arnaud-carre]

I see you have a single music during several fx and one of them is really tight in cycles. One option is to load your own music and lsp player in a « custom chip » allocation and play the music yourself ( so you can switch off the ldos cia during the tight fx) But yiu can also call lsp music tick with slighty changes in the source code

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On 14 Feb 2024, at 20:01, Jobbo ***@***.***> wrote:  At the moment it seems like the music will also stop. It seems like I need LSP_MusicPlayTick exposed. Then I have two options: 1 - Call LSP_MusicPlayTick every frame. 2 - Replace the CIA handler with a simple one that calls LSP_MusicPlayTick. A third option is that I add the simple handler on the LDOS side and add a method for telling it to swap to that handler. I can give those a try, but it seems like there's a good chance I could introduce a music glitch not matter what I do. Of the options replacing the CIA handler seems easiest and most likely to continue without glitching. — Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you commented.

[arnaud-carre]

Strange. If you switch ldos cia off you shouldnt have anything slowing down your fx. Do you compare with your fx without ldos?

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On 15 Feb 2024, at 06:06, Jobbo ***@***.***> wrote:  I gave that a try and it seems like it works. It does save a few cycles, but not really enough to solve my problems. Using insane player code might be another thing I'll try. — Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you commented.

[arnaud-carre]

oh btw I just figured out LDOS also use a very tiny VBL irq that you can switch off also ( interrupt vector $6c ). If you're really tight in cycles you can switch it off during the fx.

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On Thu, 15 Feb 2024 at 06:06, Jobbo ***@***.***> wrote: No need to keep this open. — Reply to this email directly, view it on GitHub <#7 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ADBBOHKPRZYCOUQ72S637Q3YTWJWVAVCNFSM6AAAAABDHVAUNKVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMYTSNBVGM3TSMBQGU> . You are receiving this because you commented.Message ID: ***@***.***>

[rjobling]

Good to know about the vbl irq. I'll give that a go.

I think the main problem is that I was initially testing with a simpler mod file. Now I've switch to testing with the Redux mod file and the DMA usage is pushing things over the edge, along with the CIA irq and standard LSP player.

In my standalone exe it was working okay, but that was with the simpler mod.

I'm sure can eventually get it working one way or another, I might try integrating an Insane player for the final mod into LDOS, that'll help.

Worst case I can reduce the screen area I'm using, but as I'm sure you can appreciate that feels like admitting defeat!

If you are on discord (My account is: _jobbo) it'd be nice to be able to chat on there if I need help late in the day. I'm also on twitter if you follow me back we can use that (@CosmicOrbs68k).

But most likely I have enough info to go on and I'll just need to find the right mix of optimizations.

p.s. Both LSP and LDOS are absolutely awesome! So happy to be able to use them!