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General Category => Demos => Topic started by: zhulien on 16:58, 04 August 17

Title: killmax demo
Post by: zhulien on 16:58, 04 August 17
hi, just wondering how killmax music works, whether it is using samples to make a sid-like sound or whether it does something else.  Samples I guess could be machine generated? What is the CPU overhead likely for a 6128plus to play such music and why isn't there more on CPC? It is so much more 'clear and crisp' than my C64, AY/SID hybrid music.
Title: Re: killmax demo
Post by: Ast on 20:47, 04 August 17
OffseT from futurs did this player. You could find more informations on QuasarNet (http://quasar.cpcscene.net/doku.php?id=coding:sid).
Did you ear Targhan's Mahjong sid musics ?
Title: Re: killmax demo
Post by: zhulien on 21:29, 04 August 17
I haven't heard Targhan's Mahjong sid music. but i will try find it on youtube now...
Title: Re: killmax demo
Post by: PulkoMandy on 08:56, 07 August 17
what the player does is used the 6128plus raster interrupt to trigger the SID voice changes. When the interrupt happens, the CPU then waits for part of the line to have more precise timings (otherwise you get only 64us resolution which is not enough).


CPU load is quite high (depends on the music you play and in particular on how high-pitched the SID voices are), but as this is interrupt-based, you can still run some code in the background, as long as it does not need precise timing (because it is interrupted all the time by the music playing).
Title: Re: killmax demo
Post by: roudoudou on 09:10, 07 August 17
Quote from: PulkoMandy on 08:56, 07 August 17
what the player does is used the 6128plus raster interrupt to trigger the SID voice changes. When the interrupt happens, the CPU then waits for part of the line to have more precise timings (otherwise you get only 64us resolution which is not enough).


CPU load is quite high (depends on the music you play and in particular on how high-pitched the SID voices are), but as this is interrupt-based, you can still run some code in the background, as long as it does not need precise timing (because it is interrupted all the time by the music playing).


CPU load is around 30 lines, there is no interrupt during the display of the screen as the pictures displayed use split-raster and disable interrupts. A DMA-list is modified by the player and restarted every frame.
Title: Re: killmax demo
Post by: Targhan on 10:09, 07 August 17
The Imperial Mahjong sid is quite different, because it is Sid sample. And it takes, for three channels, 100% of the CPU. And for now, my player is custom and is not publicly shared.

However, about two or three years ago, BSC released a SID Sample player, along with a small software to create your own songs with it (CPC old). You might want to browse the forum to look for it.
Title: Re: killmax demo
Post by: roudoudou on 10:23, 13 October 17
Quote from: roudoudou on 09:10, 07 August 17
CPU load is around 30 lines, there is no interrupt during the display of the screen as the pictures displayed use split-raster and disable interrupts. A DMA-list is modified by the player and restarted every frame.


A quick update, CPU load is 24 lines max for SID+samples replay ;D
Title: Re: killmax demo
Post by: zhulien on 02:55, 17 April 19
Is Targhan's Mahjong freely available? where can I get it?
Title: Re: killmax demo
Post by: Axelay on 03:11, 17 April 19
Quote from: zhulien on 02:55, 17 April 19
Is Targhan's Mahjong freely available? where can I get it?

You can get it from Targhan's site here (http://julien-nevo.com/mahjong/).
Title: Re: killmax demo
Post by: Targhan on 08:10, 17 April 19
And in my signature :).
Title: Re: killmax demo
Post by: zhulien on 06:25, 21 April 19
Quote from: Ast on 20:47, 04 August 17
OffseT from futurs did this player. You could find more informations on QuasarNet (http://quasar.cpcscene.net/doku.php?id=coding:sid).


Thanks, actually, until I read that article I never clicked as to why Toto put timers on the Play City.
Title: Re: killmax demo
Post by: OffseT on 17:44, 23 April 19
Two versions of the player exist.


One which is working like Pulko said. It has the advantage to be almost as precise as original SID player on Atari ST, at cost of CPU usage, limited to one SID channel (this one was used there: http://www.cpc-power.com/index.php?page=detail&num=10257).
One which is DMA only: less CPU usage, acceptable precision for most ST musics, up to 3 SID channels (this one was used in Killmax).
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