AD/DA pairs
- To: Tor Silfverberg <d97tsi@xxxxxxxxxx>
- Subject: AD/DA pairs
- From: Soeren Tiedemann <tiedema@xxxxxxxxxxxxxxxxxxxx>
- Date: Wed, 5 Apr 2000 12:52:34 +0200 (MESZ)
- cc: Lonnie Reed <Lonnie.Reed@xxxxxxxxxxx>, misc
- In-Reply-To: <200004031539.RAA21513@kobra.efd.lth.se>
Hi!
> I'm not sure... certainly the cpu has the power, the problem would
> probably be the analog parts. The D/A is only 8(?) bits,
Bidirectional 6 bits. According to Jeff's specs the analog coprocessor
reads a 20 bit word, sends the lower 6 bits to a DA-output converter, bit
nr. 10 indicates a cpu interrupt and the highest 6 bits are rewritten to
the memory word from an AD-input converter.
The video coprocessor is of course a specialized analog coprocessor. On
P21 it is not very useful in creating audio because the composite
output the signal levels have to match the TV-specs and are modulated by
the color burst frequency. However, Dr. Ting provides an example of using
the video-coprecessor for two voices. He used the three stable signal
levels of black, grey and sync ( 0V, 0.7V, 1.4V ) giving 2 voices.
On F21 we have analog RGB-output instead of the composite signal. Perhaps
there are more possibilities. It hasn't been tested yet.
Regards,
Soeren
