CPC-SID

[TotO]

Bus expansion got Request and Grand signal ?
If yes, may be, but for sound only... And you need more complex logic on the board.
Better to use a CPC+ ?

[Bryce]

@steve: I've never considered that. I'll take a look at what it would take when I have time, but I guess it would mean major internal changes, that most people don't like to do.

Bryce.

[redbox]

Well one thing to remember about DMA is that the Plus already has it... and it's sadly under-utilised.


Killmax and Synergy demos both have DMA sound with SID like sounds (Atari ST transfers I believe).


And according to CPCRulez the trigger for the DMA means it's possible to play samples at ~15khz with little or no processor overhead, which is very impressive.


It's definitely something I'm keen to look into, but there's precious little in the way of example source code. 

[RockRiver]

Thanks all for this "music post".
-My reference is MSX sound expansion development, and I'm fan of Arcade's sound (most of them are YM -yamaha- I.C.s)
A lot of this chips was Z80 governed in arcade's boards... (Great Ghost'n Goblins & Out Run music with lot of channels...)
see technical at: http://www.arcade-history.com/?n=ghosts%27n-goblins&page=detail&id=950
                      or: http://www.arcade-history.com/?n=out-run-deluxe-sit-down-model&page=detail&id=1898
-OK, in MSX finally they has new sound hardware but not many coders... but they found a solution: MSX expansions and software who tooks sound code for the AY and play it trought the new sound chip. This is possible with SID? or others? We need a powerfull CPU like turboR for that? CPC with another CPU is not a CPC?
-Another wet dream: play MIDI files with CPC: through AY, MIDI interface or elected yamaha new IC. [No software plays MIDIs on CPC yet] Is there a YM chip that make it natively?

Maybe these are only dreams and may be better left alone my CPC with his simple and great AY 

[TFM]

A z80 could never decode and play an MP3 at any reasonable bitrate could it?

Bryce.

You may find this of interrest:
http://www.cpcwiki.eu/index.php/FuturePlayer

[TotO]

Another wet dream: play MIDI files with CPC: through AY, MIDI interface or elected yamaha new IC. [No software plays MIDIs on CPC yet] Is there a YM chip that make it natively?

Maybe these are only dreams and may be better left alone my CPC with his simple and great AY 

YM2151 look to support MIDI in/out.
But all FM chips will never more sound like a CPC.
It's why I'll prefert to add AY channels instead.
(FM as bonus for complex sounds)

[TFM]

And according to CPCRulez the trigger for the DMA means it's possible to play samples at ~15khz with little or no processor overhead, which is very impressive.

Do you know a link in English language?

[redbox]

Do you know a link in English language?

It basically says the DMA pulls a word, being 2 bytes, from main RAM (not extra banks) every 64us which is a scan line.  The 2 bytes are 'played' and the counter is then incremented by the DMA. Because the DMA can load 2 bytes every 64us, we can get a sample rate of 15,625 kHz at 8-bit.

There are several commands, but the most useful is LOAD R,D (R being register and D being data) because it works in the same was as feeding the AY on a classic CPC.

There is some source code at the end of the article.  I've been thinking that it should be quite easy to adapt, for example, the Digidrums in this STarKos player to use the DMA channels instead of accessing the AY using the Z80 (which takes the whole frame to play a sample).

[TFM]

Ok, so the maximum transfer-rate is one AY register every 64 us. Well, if sound in created "smart", this can be enought :-)

Thank's for the translation.

[Badstarr]

I know this was discussed much earlier, but I totally agree with the idea that an add on card or peripheral device should be completely dumb without the  CPC. Projects like the SID expansion etc should show what the CPC can do when it's in the driving seat with clever coding and hardware design that work in harmony with the CPC. It should be the Z80 that does the bulk of the work, then we can rightly claim that whatever miracle is being achieved has been achieved on the CPC. If the add on device could work without it then Bryce is right, the CPC is relegated to the status of a light switch!

[TFM]

If everything depends on the cpu, then it's the cpu showing what it can do. But in this case it's not the CPC, just a cpu.


IMHO the only important point about an hardware expansion is what it can do. It really doesn't matter in which way it must be programmed or so. Only the result counts.
On the other hand my "likes" are close to the philosophy depicted by Bryce. However it just doesn't matter what I like - what matters is always the result.

[steve]

I know this was discussed much earlier, but I totally agree with the idea that an add on card or peripheral device should be completely dumb without the  CPC. Projects like the SID expansion etc should show what the CPC can do when it's in the driving seat with clever coding and hardware design that work in harmony with the CPC. It should be the Z80 that does the bulk of the work, then we can rightly claim that whatever miracle is being achieved has been achieved on the CPC. If the add on device could work without it then Bryce is right, the CPC is relegated to the status of a light switch!

If you want to demonstrate what the CPC is capable of, then you must use an unexpanded CPC, even a rampack is non-standard.
Many computers embrace the concept of the accelerator card and the CPC needs one of those more than most other computers.
Even a quad core PC has graphics and sound processors.

[MaV]

It's a question of proportionality.

While I personally wouldn't really mind an mp3-player for the CPC (as a toy), I'd nevertheless ask myself if such an add-on is even necessary. For one, the chip would be disproportionately more powerful than the Z80. And then (almost?) all of us do already have a device which is quite capable of playing mp3s.

Having the CPC play mp3s is about as ridiculous as providing an OpenGL graphics chip for it, or a math coprocessor. If I want that, I'd do this on a PC.


The CPCs strength nowadays lies in its limits and its retro-factor. Additional sound chips for the CPC (like the AYs and the SID) strengthen the latter and push the former (within reason).

And concerning the discussion about the sound chips, I can only say: Anyway it turns out, it'll be fantastic!

[TFM]

Oh, I smell the lack of fantasy     If you ever play a game on the CPC with MP3 sounds, then you won't ever like to miss it again. 


BTW.: Most GFX cards for the PC are more powerfull than the PCs CPU. 


IMHO the strength of the CPC lies in something very different than a retro factor, but I don't want to write a book here 

[MaV]

Oh, I smell the lack of fantasy     If you ever play a game on the CPC with MP3 sounds, then you won't ever like to miss it again. 

That may have been true in the 80ies or early 90ies with digitized sounds, which I craved for the CPC to have. 20 something years have passed now and every other device of the shelf can do it now. I couldn't appreciate it for what it is, if I had such a device for the CPC. Adding a couple of sound chips ... now that's another thing altogether.

BTW.: Most GFX cards for the PC are more powerfull than the PCs CPU. 

Yes, but that came as an evolution of things and started in the 90ies, much like breeding a new race of dogs. If I added a sophisticated gfx chip to a CPC that would look like a genetically engineered miniature pinscher with the anatomy of a rottweiler.

[TotO]

Instead of MSX, Spectrum or C64 users, the hardware hacking/evolution was not the taste of the CPC community.
Sure, an electronic genie was not born with this computer on hands in 80s... Because there are many improvement to do on our computer that was never done.
MSX users have been the possibility to upgrade it during all it's life, and for this community it's normal to improve sound and graphics capacity and exploit that.

On CPC, it's normal to buy a 464 instead of a 6128 an adding expensive memory and floppy expansion... Hey! What's wrong?
You don't want to play MP3 because it's a temporal junction point of the entire space-time continuum? OK.

Good luck for this nice CPC-SID project. Please, don't forget the software support if you want users do music with.
And... A passthru connector to use it with the Megaflash plugged too? 

Marty!!! Go ahead with the CPC!!!

[Badstarr]

I guess my philosophy is, Why change the CPC into a generic PC of sorts? PCs and Macs already have this sewn up. 


I have to confess though, I would be first in line for a whizzy add on that could make my CPC into something akin to a Mac or PC (preferably a akin to a Mac lol). That would be great to be able to use my CPC as a hub for email, internet, documents, photos and music production! I would swap my Mac for the CPC right away! The Symbiface goes a long way to achieving that I guess, but a large part of me would mourn the fact the CPC had become a simple terminal if the add on was the brains of the outfit.


I guess that's the paradox, it would be great to see the latest version of Quake being rendered on a GT65 screen and be able to brag about it but if it was the add on that was doing all the work, it's not really the CPC that the achievement can be attributed to.


I like it when some CPC genius finds a way to push the boundaries and make the CPC do something that was thought to be impossible. It reminds me of that line in the CPC user manual that says something along the lines of "Why is it not possible to see a man walk across the screen in the usual way...". Fast forward to 2011 and we can see full motion video on a CPC thanks to SymbOS! Someone found a way to do it!


My fear is that if we outsource tasks to much more powerful external hardware, the boundaries of the original hardware are no longer being pushed, and I think, as far as pushing them is concerned, the limit has not yet been reached.

[TotO]

I guess my philosophy is, Why change the CPC into a generic PC of sorts?

My philosophy is, why not improving the computer you love in the time?
I don't want a PC... But I will like to got 64 colors palette, 6 channels AY sound... And softwares for using that.
So, it's not a SID-CPC who really make me happy, because it will sound like a C64 and not a CPC. But it's this sort of projects that I like to see on my computer !

I have to confess though, I would be first in line for a whizzy add on that could make my CPC into something akin to a Mac or PC (preferably a akin to a Mac lol). I guess that's the paradox, it would be great to see the latest version of Quake being rendered on a GT65 screen and be able to brag about it but if it was the add on that was doing all the work, it's not really the CPC that the achievement can be attributed to.

A day, I have "dreamed" about an Ethernet board to connect your CPC to a server thru a network, using it as a "terminal".
Only sending controls to the server,  CPC engine updating GUI on bottom, playing songs and displaying the received frames on top. So... Doom in multi-players!

My fear is that if we outsource tasks to much more powerful external hardware, the boundaries of the original hardware are no longer being pushed, and I think, as far as pushing them is concerned, the limit has not yet been reached.

I understand.

[RockRiver]

C64 world loves AY-YM...
YM-64 or http://web.utanet.at/nkehrer/


Loves AY-YM world the chip SID? ?

I want a CPC-SID!!! 

[TotO]

He done a nice work with this AY "player".

[Gryzor]

Huh, imagine that!! Are there any videos around? YT shows nothing...

[RockRiver]

Hey!!!! Good CPC-SID news (sorry, another little off topic here, cause is software side. But very interesting) from TomEtJerry

SIDplayer by Geco
[attach=2]  [attach=3]

Maybe another step to SID hardware on CPC...

[TFM]

Toto: you are right. And I got no idea why a lot of CPC users fight any kind of hardware expansions.

Everybody does upgrade every system in the whole galaxis ;-) So why are some old men so stubborn and refuse anything new??

The argument that one doesn't make a PC out of a CPC is as old as stupid. I heart that already '91 and it was already wrong 20 years ago.

If we want to expand the features and power of our CPCs then we can use the most appropriate hardware. And in some cases it may be PC related, and in some cases not. For example: Why not use a USB mouse? It's cheap and it works (see adapter card from Bryce).

The point that makes the CPC-expansion-hardware-denial-philosophy is just one thing: The same people who rather kill you than adding expansions to a CPC do any kind of compiling, assembling, composing, drawing on the PC and copy only the final DSK to a CPC. How sick is that?

My philosopy is still the same: I have a CPC, I work with it, I try to expand it as much as possible. And I don't need any other computer (PC) to run it, or to create for it. But I have no problem it people do stuff on PCs for the CPC. (However I prefer the real CPC in any case, in any situation).

Back to topic! It's cool to see a CPC emualting the SID by software

[MacDeath]

Nice debate...
That's why I try to promote some stuff like Arduinos cards as generic extensions... for CPCs.

Of course, some especially designed-for custom cards would do a better job, but would be far too specific, and not even cheaper actually.


a good basic ArduinoMega may be good enough to reproduce an AY or a SID actually.


I managed to find some SID emulation at "Arduino's hobby enthousiasts" site...

http://www.arduino.cc/playground/Main/SID-emulator

But ok, this still need some custom made "shield"...

[SyX]

Another SID hardware expansion in this case for ZX
SIDBlaster on ZX-Spectrum (prototype)
PD: I would prefer more love for other YM sound chips