Well? Where is it? You have Dual Sids on the C64, Stereo Pokey on the Atari 8 bits, Ive seen some form of stereo mod for the Speccy but I have never seen anything for the CPC.
Is there are reason for this? How difficult would it be to install a dual AY system?
Technically it wouldn't be a problem to do, just no one has done it, becasue it hasn't been asked for. I even designed a stereo SID for the CPC, but I never built it.
Bryce.
Hey there Bryce!
Well, sids would be going against the nature of the cpc surely? :) But two AY chips.... even if you had a switch so the secondary AY could be on the same address as the first except with a 10ms delay (so you would get a funky echo/reverb effect for all sound/music), and switchable so that the second chip could be on a different address block for 6 channel music etc.
How hard would this be to do?
Quote from: abraXXIous on 10:00, 17 April 13
Well? Where is it? You have Dual Sids on the C64, Stereo Pokey on the Atari 8 bits, Ive seen some form of stereo mod for the Speccy but I have never seen anything for the CPC.
Is there are reason for this? How difficult would it be to install a dual AY system?
It was done and shown by SyX at Retro Madrid 2013. (4:58 on this video)
Un paseo por RetroMadrid 2013 (09/03/2013) - YouTube (http://www.youtube.com/watch?feature=player_detailpage&v=zjyy7vHuE6E#t=10s)
Quote from: abraXXIous on 10:39, 17 April 13
even if you had a switch so the secondary AY could be on the same address as the first except with a 10ms delay (so you would get a funky echo/reverb effect for all sound/music) ... How hard would this be to do?
Adding a delay would be quite tricky, as you'd need to store all AY accesses into a circular RAM buffer and replay them 4000 clock cycles later. It's doable, but it'd add a lot of complexity over just having a 2nd AY chip. That said, on an emulator it'd be almost no effort.
What if you simply added an analogue buffer and delay? Surely that could be done with a few discrete components?
Even if this was not possible, would it be possible to (again, using a simple analogue circuit, no digital processing) transpose the output of the second AY up or down one octave?
Quote from: abraXXIous on 11:17, 17 April 13
What if you simply added an analogue buffer and delay? Surely that could be done with a few discrete components?
Even if this was not possible, would it be possible to (again, using a simple analogue circuit, no digital processing) transpose the output of the second AY up or down one octave?
Like said 3 posts over, it was done... (and more simply)
Quote from: TotO on 11:25, 17 April 13
Like said 3 posts over, it was done... (and more simply)
So which one was done? Echo effect or transposition?
The board add a second sound chip on the expansion connector that allow to play 3 more AY channels using a different port.
It can be set to replay CPC or ST sound frequencies, w/o programming the PIO.
Quote from: TotO on 13:00, 17 April 13
The board add a second sound chip on the expansion connector that allow to play 3 more AY channels using a different port.
It can be set to replay CPC or ST sound frequencies, w/o programming the PIO.
I was going to ask if it supported a 2MHz mode, so that's a neat feature. Next step - piggyback the AY on top of the existing AY inside the CPC and provide both with 2MHz options :-)
Quote from: Sykobee (Briggsy) on 13:40, 17 April 13
I was going to ask if it supported a 2MHz mode, so that's a neat feature. Next step - piggyback the AY on top of the existing AY inside the CPC and provide both with 2MHz options :-)
Sounds like a project for someone with the hardware hat on.... Bryce? :)
TotO and SyX are well capable of doing a project like this. They don't need me.
Bryce.
Quote from: abraXXIous on 10:00, 17 April 13
Well? Where is it?
It's not needed, because the CPC's AY does produce stereo by itself - in contrast to the mono sid of the c64.
The native CPC already does stereo - just connect your stereo amplifier.
For more you have to wait until a near hardware release. It's not my job to take the surprise away, but your patience will pay off.
Quote from: TFM/FS on 17:09, 17 April 13
It's not needed, because the CPC's AY does produce stereo by itself - in contrast to the mono sid of the c64.
The native CPC already does stereo - just connect your stereo amplifier.
For more you have to wait until a near hardware release. It's not my job to take the surprise away, but your patience will pay off.
Well, stereo sound is not what I was getting at, dual AY would double the number of available voices... so no clues as to what this impending hardware release is.... besides something CPC and audio related? :)
Such a daughterboard was described in a hardware book by Data Becker. I am not sure if it was published somwhere else, too. Maybe I have enough time to scan the schematics and put them into a Wiki page this weekend...
TotO can correct me if I'm wrong, but in their mod the second AY (or YM) plays the sound in mono.
True.
On the prototype shown at Retro Madrid, the board replay 6ch music through the embedded speaker (mono).
Quote from: abraXXIous on 20:25, 17 April 13
Well, stereo sound is not what I was getting at, dual AY would double the number of available voices... so no clues as to what this impending hardware release is.... besides something CPC and audio related? :)
wait. I am sure it will be worth it.