Where the hell is the dual AY / Stereo mod for the CPC range?!

abraXXIous · 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?

Bryce · 10:22, 17 April 13

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.

abraXXIous · 10:39, 17 April 13

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?

TotO · 10:49, 17 April 13

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

ralferoo · 11:05, 17 April 13

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.

abraXXIous · 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?

TotO · 11:25, 17 April 13

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)

abraXXIous · 11:40, 17 April 13

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?

TotO · 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.

Sykobee (Briggsy) · 13:40, 17 April 13

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 :-)

abraXXIous · 13:57, 17 April 13

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?

Bryce · 14:01, 17 April 13

TotO and SyX are well capable of doing a project like this. They don't need me.

Bryce.

TFM · 17:09, 17 April 13

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.

abraXXIous · 20:25, 17 April 13

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?

Octoate · 21:32, 17 April 13

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...

McKlain · 22:29, 17 April 13

TotO can correct me if I'm wrong, but in their mod the second AY (or YM) plays the sound in mono.

TotO · 09:08, 18 April 13

True.
On the prototype shown at Retro Madrid, the board replay 6ch music through the embedded speaker (mono).

arnoldemu · 09:29, 18 April 13

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.

News:

Where the hell is the dual AY / Stereo mod for the CPC range?!