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Genesis8 - C64 SID on Amstrad CPC, software or hardware ?

Started by NewsBot, 00:01, 24 June 12

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Bryce

Possible, but I would need to calculate it exactly, it might cause quality problems to the stereo output.

Bryce.

TotO

May be, using a varistance to test the good input value and adjust the mixing volume.
On Amiga, you got the same (with stereo) on the expansion port, but nobody want to add more than Paula... XD

If that work fine, it's a clever way than the external cable.
"You make one mistake in your life and the internet will never let you live it down" (Keith Goodyer)

MacDeath

QuoteI could easily make a few Stereo AY or Stereo SID expansions, but they wouldn't be cheap, especially with the stupid prices they are asking for on ebay these days. I have a cheap source for AYs, but not for SIDs. But I doubt there is enough people interested to make a batch anyway.
hence the Arduino solution.

at the Arduino forum/playground, there is even a code to get a Sid emulated on those.

Arduino playground - SID-emulatorCode
Arduino playground - SID-emulator

oh wait, it is actually a shield, not done by the Arduino itself, oops... I was mistaken.

Arduino playground - ArduinoSynth


still i remember someone doing a one-chip-AtariST and he gave some codes to implement the YM...
http://dev-docs.atariforge.org/files/alltogether.pdf

other stuffs :
SIDaster – MOS6581 Arduino Shield | FULLMAJ
http://fullmaj.rd-h.fr/wiki/doku.php?id=sidaster
http://fullmaj.rd-h.fr/wiki/doku.php?id=sidaster_shield

what is the price for those ?

Also can't such SID or AY be done by the Arduino itself ?
Of course a shield would still be needed to interface the sound outputs and mix them, or even to interface with the CPC itself.
I guess.


anyway, provided you own something like this :

you may just need a simple audio output from the soundcard and mix it yourself with the CPC/PLUS audio out.

if not, lets go for the onboard solution.

TotO

If I remember, Bryce said to you that he don't want to use "Arduino kikou lol" stuff on the CPC.
"You make one mistake in your life and the internet will never let you live it down" (Keith Goodyer)

Bryce

Arduino must be paying you a fortune for all the advertising you do for them :D . If you are happy to use an emulated non-real SID, then you can pick up a Nano-SwinSID for a few Euros: SwinSID – C64-Wiki You don't need an entire Arduino, just to simulate an IC.

Bryce.

arnoldemu

dual ay's in a cpc, or on an expansion board. Yes!!!!!!!!

I would also like to see a dma sound board similar to the sound board on the aleste, but I know it's more work.
dual ay first :)
My games. My Games
My website with coding examples: Unofficial Amstrad WWW Resource

Bryce

Adding DMA to the CPC (for any purpose) would involve an aweful lot of internal changes, track cutting etc. Even if I designed it, I doubt many (if anyone) would be prepared to cut up their beloved CPC to that extent.

Bryce.

ralferoo

Quote from: Briggsy on 18:09, 03 July 12
Are there any AY FPGA implementations?
Yes. There's at least one implementation knocking around that I think was done for FPGA Arcade that's easy to find if you search for it, i.e. google "AY vhdl"

There's also my (closed-source for now) implementation which is heavily optimised for number of gates and includes the PWM in the AY core, which should synthesize to about half the size (although I've never actually tried the other one). It's a feature I'll definitely considering adding to my emulator as having a dual AY core should only require about 25% more gates than my existing implementation.

TotO

I though that an AY/YM chip cost less than FPGA and are 100% accurates.




"You make one mistake in your life and the internet will never let you live it down" (Keith Goodyer)

ralferoo

Quote from: TotO on 11:10, 04 July 12
I though that an AY/YM chip cost less than FPGA and are 100% accurates.
Sure, if you just want an AY, then yeah just buy one. Although, they might be hard to get hold of nowadays, I've not looked.

The benefit of an FPGA design is that you can integrate everything in a single chip, and in fact that's exactly what I'm doing in my pet project... ;)

Sykobee (Briggsy)

Quote from: ralferoo on 09:54, 04 July 12
There's also my (closed-source for now) implementation which is heavily optimised for number of gates and includes the PWM in the AY core, which should synthesize to about half the size (although I've never actually tried the other one). It's a feature I'll definitely considering adding to my emulator as having a dual AY core should only require about 25% more gates than my existing implementation.


Good work, I look forward to your core. Are you also considering adding the additional features of the AY-8930 in the future - I'm sure some demos would make good use of it?

ralferoo

Quote from: Briggsy on 12:44, 04 July 12
Good work, I look forward to your core.
I'm actually making it for my CPC emulator board, there's a blog here: CPC FPGA - Recreation of an Amstrad CPC on an FPGA
Quote
Are you also considering adding the additional features of the AY-8930 in the future - I'm sure some demos would make good use of it?
I'd never even heard of that variant before, but I'll try and find the datasheet and see what it adds...

IanS

Quote from: Bryce on 09:30, 04 July 12
Adding DMA to the CPC (for any purpose) would involve an aweful lot of internal changes, track cutting etc. Even if I designed it, I doubt many (if anyone) would be prepared to cut up their beloved CPC to that extent.

I've not tried it, but is there any reason why the standard z80 BUSREQ/BUSAK DMA wouldn't work on the CPC?

Bryce

The Gate Array doesn't read or adhere to either of those signals, which would probably cause clashes and crashes.

Bryce.

Executioner

Well, perhaps rather than DMA, you could have some sort of on-board memory to feed the AY/SID registers every 64 microseconds with registers > 16 being used to stop or loop the feed and the Z80 able to write the memory when the feed is disabled. Like a simple version of the Plus DMA.

TotO

Quote from: Executioner on 00:49, 05 July 12
Well, perhaps rather than DMA, you could have some sort of on-board memory to feed the AY/SID registers every 64 microseconds with registers > 16 being used to stop or loop the feed and the Z80 able to write the memory when the feed is disabled. Like a simple version of the Plus DMA.
An interesting thing will be to get a programmable timer that allow to disable INT and manage your owns for custom uses.
With that, you can get rasters each line, manage pseudo DMA, ...
(and why not a blitter... sorry :D)
"You make one mistake in your life and the internet will never let you live it down" (Keith Goodyer)

RockRiver

Great!! Yes!! more music for our CPCs: I like a lot all that iconoclastic ideas:  ;)

- software SID player
- hardware SID player (one or two chips)
- hardware stereo AY/YM
- DMA SID for CPC+
- pseudo DMA for originalCPC
- And maybe another famous chiptune Yamaha SoundChips attached to CPC

As musician and still CPC user here are my dreams, mates. Thanks to Geco, Bryce and all of you, CPC coders and musicians
Geco said: http://chipmusic.org/forums/post/89178/#p89178

khisanth

I would also like to see some C64 tunes done on the Amstrad, such as Wizball or Last Ninja to see how they compare.

TFM

Quote from: RockRiver on 23:43, 12 August 12
- DMA SID for CPC+
Maybe it would be good to have _ONE_ DMA player at all. IIRC we have none.
TFM of FutureSoft
Also visit the CPC and Plus users favorite OS: FutureOS - The Revolution on CPC6128 and 6128Plus

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