Re: ECHO+ Card

[mjmahon@aol.com (Michael J. Mahon)]

Eric asked:

>> While it has the same sound generators as the Mockingboard, they
>> are both controlled by one 6522 (while the Mockingoard uses two),
>> so it is not compatible with the Mockingboard at the hardware level.
>>
>> FWIW, it surprised me when I saw that the Mockingboard used two
>> 6522s to control two 8910s.  Each 6522 has two 8-bit ports, and one
>> would have sufficed.  (Of course, another would have been required to
>> add speech, then.)  It seems that the Mockingboard was simply a
>> "doubled" mono design.  The early models even brought the "extra"
>> 8-bit parallel port of the 6522 out to a header on the card.
>>
>
>Is that the reason you only get to listen to 1 side of the speaker (left OR
>right speaker, without using any mono-to-stereo adaptor) when there's only 1
>sound generator/speech chip installed on the Mockingboard?

Yes, there is one sound generator connected to each channel.

>Speaking about speech chip, where in the world can I find a SSI-263 speech
>chip?

Good question--I had the most luck finding them in Mockingboards.  ;-)

-michael

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