Re: Universal Sound Boards

>Is the sound data for these boards loaded at "boot" time and kept on the
>Universal Sound Board, or is the data for the sounds loaded each time the
>sound is used?

It's a one-time load IIRC.

>What is a common failure on these boards?

The few that I worked on (and I kept it to a few-- those things are
complicated!) all had problems with the digital switches (CD4016's?).

>What problems would cause the following symptoms:
>1) Only static is output
>2) Last note of certains sounds stick
>3) Wrong sound is played

Bad sound trigger from bus (incorrect sound command sent) or bad download
code to the USB would be my first guesses. But, one thing about the USB--
it's flexible as hell. You can route stuff all over the place and change
the behavior on the fly. (I still think it would make a pretty sweet
vintage-synth... :-) I only was able to mildly understand everything they
can do-- makes it tricky to troubleshoot.

>Is there anyway to trigger the sounds manually using a logic pulser
>(instead
>of having to play the game or go through test mode)?

Not that I'm aware of. You need to send it a command over the backplane to
its IO ports. (Or I suppose you could replace the code it's running on the
fly and reset it. That would be a lot of work for game mode, but easy
enough for just testing stuff out.)

>Any additional advice for repairing these boards, common solutions, or
>debugging tips would be appreciated. I've been using the Star Trek manual
>to figure out which sounds come from which channels, and I have all the
>channels mapped to components, but not sure how to tell which component is
>suspect.

That about how I did it. I did it mostly brute-force-- start looking at the
end of the signal chain and work backwards until something doesn't look
right. It's helpful to have a known-working board to get a feel for how the
signals *should* look for a particular sound.

I also took advantage of the 'map' of which voices were used in which sounds
to try to derive where a problem was. (If all "channel 2" sounds are
affected -- check the channel 2 components. If only *some* channel 2 sounds
were effected, check the mixer area.)

-Clay

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Received on Wed Nov 14 23:26:45 2001