AY-3 8910 adapter for Amstrad CPC, to STOP exploitation for AY-3 8912!

Started by ikonsgr, 16:50, 19 August 22

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stulish


I have had a look at the new Membrane using my camera (zoomed in), and as there were so many keys not working looked at the areas where all tracks are close (the ribbon).

it looks like there are cracks along the tracks along a piece of strengthening backing (see images)

I have sent the images to the place where i purchased the membrane from to see what they think.

zhulien

Would it be worth adding a socket for an optional second soundchip? Either another at or a sid... or both. 

stulish


stulish

Originally i thought i could use pins to go directly from the pcb into the motherboard with the new AY-3-8910 IC fitted but this will not work as the PCB will foul on the capacitors on the right of the photos.

so i think the only way to install will be to use individual wires from the PCB to the motherboard.

Regards

Stu



ikonsgr

Quote from: stulish on 22:55, 13 September 22Originally i thought i could use pins to go directly from the pcb into the motherboard with the new AY-3-8910 IC fitted but this will not work as the PCB will foul on the capacitors on the right of the photos.
so i think the only way to install will be to use individual wires from the PCB to the motherboard.
Regards
Stu

Thanks stulish for being a "beta tester" for the board!  :)
Now, you think that if i cut the part in red rectangle:

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 board will fit on AY 8912 Socket without bumping on the caps? Also, apart from the caps, is there any other place of board which might not fit and need a bit "Triming" too?

ikonsgr


stulish

Quote from: ikonsgr on 21:22, 15 September 22@stulish , you think this will fit?

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I think the only way to make it fit would be to turn the 8910 IC 90 degrees so it sits above the IC's below, my very poor drawing shows what i think, but not sure if this is achievable?

stulish

Just as an update after finding the cracks in the tracks bu the connector, the company are sending me another membrane (hopefully this will work fine).

:)

gerald

Just a warning : piling up IC/PCB where the keyboard membrane wraps is a not a good thing. There is less than 0.5cm for the membrane to wrap and there is a chance of stressing/damaging it there.

The only way to avoid this stress is to make sure the membrane wraps toward the outside of the CPC instead of the inside as it would naturally do.

Bryce

Quote from: zhulien on 01:52, 09 September 22Would it be worth adding a socket for an optional second soundchip? Either another at or a sid... or both.
A second AY wouldn't be too difficult, but it would need a little more than just a socket. You'd need separate addressing from the 8255. Adding a SID would be rather complicated. It would need a lot of additional circuitry.

Bryce.

TotO

The goal is to replace a defective soundchip with something not expensive.
If you start to add extra chips, that mean you have the money to buy the 8912 alone. ;D
"You make one mistake in your life and the internet will never let you live it down" (Keith Goodyer)

Bryce

Quote from: TotO on 12:19, 18 September 22The goal is to replace a defective soundchip with something not expensive.
If you start to add extra chips, that mean you have the money to buy the 8912 alone. ;D
You can buy a box of AY's for the price of a SID!!! :D

Bryce.

TotO

Quote from: Bryce on 08:24, 19 September 22You can buy a box of AY's for the price of a SID!!! :D
True. For the price of the SID you can buy a Play2CPC, a better deal for the CPC users.
What is funny is the speculation around the SID chip finally not so rare to find.
"You make one mistake in your life and the internet will never let you live it down" (Keith Goodyer)

GUNHED

Get a LambdaSpeak FS for the price of the SID and enjoy all you miss when using a SID.  ;D ;D ;D
http://futureos.de --> Get the revolutionary FutureOS (Update: 2023.11.30)
http://futureos.cpc-live.com/files/LambdaSpeak_RSX_by_TFM.zip --> Get the RSX-ROM for LambdaSpeak :-) (Updated: 2021.12.26)

ikonsgr

Quote from: stulish on 18:12, 17 September 22I think the only way to make it fit would be to turn the 8910 IC 90 degrees so it sits above the IC's below, my very poor drawing shows what i think, but not sure if this is achievable?

  I don't think this arrangment would fit either. It would require for the hole 40pin socket to be placed under the 28pin socket, which surely will hit onto CRT6845 chip.
Anyway,i believe the indentation of the new design would fit, maybe by pushing a bit  the cap. I also trim it a bit more: https://www.dropbox.com/s/wc9q8cd3ujkkbnm/8910_8912.jpg?dl=0
Anyway this is the new gerber files for anyone wants to try it: https://www.dropbox.com/s/3njnpasra51mcdp/ay3%208912_8910%20adapter_gerber.zip?dl=0

ajcasado

Quote from: zhulien on 01:52, 09 September 22Would it be worth adding a socket for an optional second soundchip? Either another at or a sid... or both.
I guess that managing a shift register with the extra GPIO port of the 8910 you could control any number of extra chained AY's.
CPC 664

Empiezas a envejecer cuando dejas de aprender.
You start to get old when you stop learning.

TotO

Quote from: ajcasado on 08:51, 22 September 22I guess that managing a shift register with the extra GPIO port of the 8910 you could control any number of extra chained AY's.
Sure, but il will be slow to control extra AYs requiring to access PPI->AY->AY. (and probably some logic for the data bus)
And currently, I can read that is difficult to physically fit one 8910. ;D
"You make one mistake in your life and the internet will never let you live it down" (Keith Goodyer)

ajcasado

Quote from: TotO on 09:07, 22 September 22
Quote from: ajcasado on 08:51, 22 September 22I guess that managing a shift register with the extra GPIO port of the 8910 you could control any number of extra chained AY's.
Sure, but il will be slow to control extra AYs requiring to access PPI->AY->AY. (and probably some logic for the data bus)
And currently, I can read that is difficult to physically fit one 8910. ;D
Totally agree, but it could be a nice experiment in case you have to replace the ay from your CPC.
CPC 664

Empiezas a envejecer cuando dejas de aprender.
You start to get old when you stop learning.

TotO

Quote from: ajcasado on 09:18, 22 September 22Totally agree, but it could be a nice experiment in case you have to replace the ay from your CPC.
The more easy and cheap is to add a R2R DAC on the GPIO B, under the 8910 socket to replay PCM sample like the Digiblaster.
If people would like extra audio channels, it already exist some expansions for that (PlayCity, LSFS, Willy, Play2CPC, more?) and the free room inside a CPC can probably allow to embed some of them using an internal expansion ribbon cable, if not external.
"You make one mistake in your life and the internet will never let you live it down" (Keith Goodyer)

ajcasado

Quote from: TotO on 09:28, 22 September 22
Quote from: ajcasado on 09:18, 22 September 22Totally agree, but it could be a nice experiment in case you have to replace the ay from your CPC.
The more easy and cheap is to add a R2R DAC on the GPIO B, under the 8910 socket to replay PCM sample like the Digiblaster.
If people would like extra audio channels, it already exist some expansions for that (PlayCity, LSFS, Willy, Play2CPC, more?) and the free room inside a CPC can probably allow to embed some of them using an internal expansion ribbon cable, if not external.
The DAC thing is a very nice idea. :o
CPC 664

Empiezas a envejecer cuando dejas de aprender.
You start to get old when you stop learning.

TotO

Quote from: ajcasado on 09:37, 22 September 22The DAC thing is a very nice idea. :o
Hehe. You have liked the idea on September 1st. :)

Here the next post: (require to test the audio mix)
https://www.cpcwiki.eu/forum/index.php?msg=219378
"You make one mistake in your life and the internet will never let you live it down" (Keith Goodyer)

ajcasado

Quote from: TotO on 10:24, 22 September 22
Quote from: ajcasado on 09:37, 22 September 22The DAC thing is a very nice idea. :o
Hehe. You have liked the idea on September 1st. :)

Here the next post: (require to test the audio mix)
https://www.cpcwiki.eu/forum/index.php?msg=219378

Wow, completely forgotten. At least I'm coherent with myself, not always an easy thing to achieve.  :P
CPC 664

Empiezas a envejecer cuando dejas de aprender.
You start to get old when you stop learning.

ikonsgr

I just try the new adapter boards and with a little cap bend, they seem to fit on a CPC 6128:

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TotO

If the GPIO is a problem to fit, remove it. (at less from this side)
"You make one mistake in your life and the internet will never let you live it down" (Keith Goodyer)

ikonsgr

Quote from: TotO on 20:37, 17 December 22If the GPIO is a problem to fit, remove it. (at less from this side)
I don't think GPIO would be a problem.
 Adapter shown in photo, sits on a AY8912 chip, directly soldered on board (i only alligned the 8912 holes to be exactly above the chip), but i suppose that in "real use", there will be a 28pin socket for the 8912 soldered on board, so adapter will plug much higher than shown in photo.
I have a CPC6128 with all chips in sockets, so maybe i will open this one, solder round pins on the adapter and have it plug to see exactly how it looks!   ;)

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