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Stef
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Joined: 30 Nov 2006
Posts: 1253
Location: France - Sevres
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 Posted: Sun Feb 22, 2009 4:24 pm Post subject: Z80 driver - 4 channels player with volume control. |
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Lately i had to rewrite my 4ch player Z80 driver as i lost some sources :-/ Wasn't that bad after all as i was capable to improve it and get more "free time" than my first shoot. I have about 48 free slots (/256), a bit less than 20% of Z80 time which is enough to handle some YM2612 or/and PSG command 
Finally i decided to add volume control with this available time.
I couldn't do more than 16 levels volume control because of Z80 ram limitation. The driver is only handling channel volume for now but i think i can add global volume with the 8 free slots leaving :p
You can download the rom here (the rom name is pl4ch_01.bin)
This driver gimme some ideas as doing a MOD converter : we can build samples at all needed rates and handle ADSR envelop "in software" by adjusting envelop on the fly (once by frame should be ok) X'D
Last edited by Stef on Sun Feb 22, 2009 4:56 pm; edited 1 time in total |
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mic_
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Joined: 12 Aug 2008
Posts: 250
Location: Sweden
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| Posted: Sun Feb 22, 2009 4:47 pm Post subject: |
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| Quote: | | You can download the rom here. |
The page briefly displays some message in french, then it goes blank and nothing happens. |
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Shiru
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Joined: 07 Apr 2007
Posts: 786
Location: Russia, Moscow
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| Posted: Sun Feb 22, 2009 4:48 pm Post subject: Re: Z80 driver - 4 channels player with volume control. |
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Link does not work, empty page.
| Stef wrote: | | we can build samples at all needed rates |
No pitch effects then (arpeggio, slides, portamento, vibrato), or you'll need very many samples.
Last edited by Shiru on Sun Feb 22, 2009 4:48 pm; edited 1 time in total |
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TmEE co.(TM)
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Joined: 05 Dec 2006
Posts: 1941
Location: Estonia, Mahtra village
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| Posted: Sun Feb 22, 2009 4:55 pm Post subject: |
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Also cannot get anything :/
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Stef
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Joined: 30 Nov 2006
Posts: 1253
Location: France - Sevres
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| Posted: Sun Feb 22, 2009 4:56 pm Post subject: |
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| sorry, i fixed the link ! |
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Stef
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Joined: 30 Nov 2006
Posts: 1253
Location: France - Sevres
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| Posted: Sun Feb 22, 2009 4:58 pm Post subject: Re: Z80 driver - 4 channels player with volume control. |
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| Shiru wrote: | Link does not work, empty page.
| Stef wrote: | | we can build samples at all needed rates |
No pitch effects then (arpeggio, slides, portamento, vibrato), or you'll need very many samples. |
Does MOD support all that ?? well i suppose i've been optimist :p
anyway we can have a sort of very simple MOD player i guess |
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mic_
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Joined: 12 Aug 2008
Posts: 250
Location: Sweden
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Stef
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Joined: 30 Nov 2006
Posts: 1253
Location: France - Sevres
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| Posted: Sun Feb 22, 2009 5:16 pm Post subject: |
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hmmm ok so MOD won't be that easy ^^ |
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TmEE co.(TM)
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Joined: 05 Dec 2006
Posts: 1941
Location: Estonia, Mahtra village
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| Posted: Sun Feb 22, 2009 5:20 pm Post subject: |
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now it works, pretty nice, and quality is very good too 
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Shiru
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Joined: 07 Apr 2007
Posts: 786
Location: Russia, Moscow
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| Posted: Sun Feb 22, 2009 5:40 pm Post subject: Re: Z80 driver - 4 channels player with volume control. |
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| Stef wrote: | | anyway we can have a sort of very simple MOD player i guess ;) |
Yes, but it will barely usable because of many drawbacks:
- It will require to write new music for it (taking all limitations in account)
- To compensate lack of pitch effects longer samples will be needed (takes more memory itself, and much more when duplicated with all pitches)
- Music data will be large anyway
- Not very suitable for games, because no sampled sound effects (or muting music channels, which is sounds bad, or 2-3 channels music, or lower quality of sound to make additional channels for effects) |
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Stef
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Joined: 30 Nov 2006
Posts: 1253
Location: France - Sevres
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| Posted: Sun Feb 22, 2009 5:56 pm Post subject: Re: Z80 driver - 4 channels player with volume control. |
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| Shiru wrote: | | Stef wrote: | | anyway we can have a sort of very simple MOD player i guess |
Yes, but it will barely usable because of many drawbacks:
- It will require to write new music for it (taking all limitations in account)
- To compensate lack of pitch effects longer samples will be needed (takes more memory itself, and much more when duplicated with all pitches)
- Music data will be large anyway
- Not very suitable for games, because no sampled sound effects (or muting music channels, which is sounds bad, or 2-3 channels music, or lower quality of sound to make additional channels for effects) |
True, not very suitable for real use afaik... just a proof of concept |
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Stef
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Joined: 30 Nov 2006
Posts: 1253
Location: France - Sevres
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| Posted: Sun Feb 22, 2009 5:59 pm Post subject: |
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| TmEE co.(TM) wrote: | | now it works, pretty nice, and quality is very good too |
Thanks
Strangely the quality is better than my first driver which was using similar code at the same output rate :-/ |
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TmEE co.(TM)
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Joined: 05 Dec 2006
Posts: 1941
Location: Estonia, Mahtra village
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Stef
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Joined: 30 Nov 2006
Posts: 1253
Location: France - Sevres
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| Posted: Mon Feb 23, 2009 2:05 pm Post subject: |
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Thanks
Unfortunatly i lost my password for my usual FTP so i had to do with this crappy stuff. |
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Snake
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Joined: 13 Sep 2008
Posts: 200
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| Posted: Thu Feb 26, 2009 11:54 pm Post subject: |
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| Stef wrote: | | TmEE co.(TM) wrote: | | now it works, pretty nice, and quality is very good too |
Thanks
Strangely the quality is better than my first driver which was using similar code at the same output rate :-/ |
I often find I write something better the second time around Probably some bug, typo, or timing error that was too easy to miss. |
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