Spectrum Computing

Posted: **Sat Aug 11, 2018 11:48 am**

Hi

I have just bought a simple AY board with a Pass-Through connector fitted and i cannot get any sound out of it. There is some faint distorted sound playing Exolon but only shooting and explosions - no music, no sound at all from Cybernoid 2. These are both listed as being 48K/AY games. The pass through works and i have used my Smart Card V2 to load the games and loaded the games via my laptop. Getting nothing.

There are no jumpers on the board and the AY chip is a MSound AY38912/P made in 9807 MICREL there is no sign of any loose or bad solder joints.

Does anyone have any suggestions???

Thanks in advance.

Posted: **Sat Aug 11, 2018 2:53 pm**

Have you loaded the 128k version of Cybernoid II (CybernoidII-TheRevenge128.tap) the 48k version only uses the beeper, the 128k version works on a 48k model +AY. No idea about Exolon though.

Posted: **Sat Aug 11, 2018 4:12 pm**

I have not tried that i have to admit. I have tried Bosconian 87 and that is supposed to have AY music, with headphone all I can hear is some distorted clicks,scratches,white noise where it almost sounds like it is trying to play some music. I think the AY chip may be faulty.

Are there any ways to POKE/PEEK the AY chip to test it is OK???

Posted: **Sat Aug 11, 2018 5:18 pm**

Exolon won't play the music, if it finds an original 48K ROM.

Try something like Into The Eagles Nest, which lets you manually choose 48K/128K sounds.

Try this and see if you get the same value back:
OUT 65533,0
OUT 49149,x
PRINT IN 65533

Posted: **Sat Aug 11, 2018 6:59 pm**

Most AY boards need their audio output connecting to an audio amplifier. The output from the sound chip can't drive headphones.

Mark

Posted: **Sun Aug 12, 2018 6:43 am**

jmk wrote: ↑Sat Aug 11, 2018 5:18 pm Exolon won't play the music, if it finds an original 48K ROM.

Try something like Into The Eagles Nest, which lets you manually choose 48K/128K sounds.

Try this and see if you get the same value back:
OUT 65533,0
OUT 49149,x
PRINT IN 65533

Yes i get the same value back, does this mean the AY chip is working properly???

Posted: **Sun Aug 12, 2018 6:51 am**

1024MAK wrote: ↑Sat Aug 11, 2018 6:59 pm Most AY boards need their audio output connecting to an audio amplifier. The output from the sound chip can't drive headphones.

Mark

I tried it with headphones and i also use the left/right audio inputs on my TV using a 3.5 to RCA Phono x 2 and i get no sound when selecting 128K sound on Into the Eagles Nest apart from some distorted clicks when firing you gun and I have the same distorted clicks/white noise when playing Bosconia 87. It's like the games are detecting a AY Chip but the sound isn't working.

I based the headphone usage on Byte Delight's Manual and Product as this came with no Instructions and they were only small earbuds. I didn't use the earphones until after I had no joy with the TV.

I think I am going to ask for a refund and get the one I should have got in the first place. Lesson learned.

Posted: **Sun Aug 12, 2018 6:37 pm**

Morpheus wrote: ↑Sun Aug 12, 2018 6:43 am
jmk wrote: ↑Sat Aug 11, 2018 5:18 pm Exolon won't play the music, if it finds an original 48K ROM.

Try something like Into The Eagles Nest, which lets you manually choose 48K/128K sounds.

Try this and see if you get the same value back:
OUT 65533,0
OUT 49149,x
PRINT IN 65533
Yes i get the same value back, does this mean the AY chip is working properly???

Well, the chip is correctly connected at least. That says nothing about the output.

Try this for the output, it should give you 3 channels of 440 hz tone, at maximum volume:

; Output channels A, B and C with tone, no noise.
OUT 65533,7: OUT 49149,248 ; 254 = A only, 253 = B only, 251 = C only, 252 = A & B, 250 = A & C, 249 = B & C

; Channel A max volume, no envelope.
OUT 65533,8: OUT 49149,15

; Channel B max volume, no envelope.
OUT 65533,9: OUT 49149,15

; Channel C max volume, no envelope.
OUT 65533,10: OUT 49149,15

; Set channel A to 440 hz.
OUT 65533,0: OUT 49149,254
OUT 65533,1: OUT 49149,0

; Set channel B to 440 hz.
OUT 65533,2: OUT 49149,254
OUT 65533,3: OUT 49149,0

; Set channel C to 440 hz.
OUT 65533,4: OUT 49149,254
OUT 65533,5: OUT 49149,0

Posted: **Mon Aug 13, 2018 9:25 am**

jmk wrote: ↑Sun Aug 12, 2018 6:37 pm
Morpheus wrote: ↑Sun Aug 12, 2018 6:43 am Yes i get the same value back, does this mean the AY chip is working properly???
Well, the chip is correctly connected at least. That says nothing about the output.

Try this for the output, it should give you 3 channels of 440 hz tone, at maximum volume:

; Output channels A, B and C with tone, no noise.
OUT 65533,7: OUT 49149,248 ; 254 = A only, 253 = B only, 251 = C only, 252 = A & B, 250 = A & C, 249 = B & C

; Channel A max volume, no envelope.
OUT 65533,8: OUT 49149,15

; Channel B max volume, no envelope.
OUT 65533,9: OUT 49149,15

; Channel C max volume, no envelope.
OUT 65533,10: OUT 49149,15

; Set channel A to 440 hz.
OUT 65533,0: OUT 49149,254
OUT 65533,1: OUT 49149,0

; Set channel B to 440 hz.
OUT 65533,2: OUT 49149,254
OUT 65533,3: OUT 49149,0

; Set channel C to 440 hz.
OUT 65533,4: OUT 49149,254
OUT 65533,5: OUT 49149,0

Hi JMK
Thanks for all your help to date you have been a great help. I have tried all the combinations of the OUT commands you listed and the Speccy reports back with an OK but there is no sound at all on any of the options i tried.
I have never seen an AY chip made by Msound and i can only conclude it's a fake chip or it's a genuine chip but it's faulty. I have started a return on PayPal but the seller has not responded so far.

You know the old saying if it is too good to be true it usually is... I think that applies here.

I guess i could always try and get a AY chip myself as the PCB probably works - the only other thing would be the crystal and i don't know how i would test that.

Posted: **Wed Aug 22, 2018 4:42 am**

Hi
Just thought I would follow up on this It turned out to be a SMD component that was not soldered on one pad. One of the two 470R resistors coming from the Crystal.
By the time I found that I had already shelled out £9 for a new AY Chip. So it works fine now.

Posted: **Wed Aug 22, 2018 11:55 am**

Good to hear that the problem is sorted

Did you get help from the seller?

Have fun

Mark

Posted: **Tue Sep 04, 2018 2:30 pm**

Hi
Just thought I would follow up on this It turned out to be a SMD component that was not soldered on one pad. One of the two 470R resistors coming from the Crystal.
By the time I found that I had already shelled out £9 for a new AY Chip. So it works fine now.

Yeah I did they gave me the cost of the AY Chip back as a refund so it worked out OK in the end.

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