[Coco] Speech/Sound cartridge

[Bob Devries]

George,

The stock SSC did have an issue with running at 2MHz. There were a couple of 
suggested fixes, including replacing a transistor with another type. This is 
the road I took, and it was successful.

There's only one transistor in the SSC, a 2SA984K (Q1), a PNP. From memory 
(and someone correct me if I'm wrong), I replaced it with a 2N3906. Be 
careful to match the pins correctly. I seem to remember that the 2N3906 had 
it's pins different from the existing transistor.

Other fixes were also suggested, which may or may not be easier or more 
effective.

The problem (as I understood it) was that no (or low) -5 volt was generated 
to drive the op-amps.

--
Regards, Bob Devries, Dalby, Queensland, Australia

Isaiah 50:4 The sovereign Lord has given me
the capacity to be his spokesman,
so that I know how to help the weary.

website: http://www.home.gil.com.au/~bdevasl
my blog: http://bdevries.invigorated.org/

----- Original Message ----- 
From: "George Ramsower" <georgeramsower at gmail.com>
To: <coco at maltedmedia.com>
Sent: Sunday, February 08, 2009 12:09 PM
Subject: [Coco] Speech/Sound cartridge


> Was there an issue with the SSC running a CC3 at 2mhz? I'm about to add 
> this cart to one of my OS9 systems on a CC3.
>
> George
>
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