Re: Zektor snd bd component differences and missing snds

On May 2, 8:12pm, fishd wrote:
> Subject: Zektor snd bd component differences and missing snds
> Hi Folks,
>
> After comparing the schematics for both the Eliminator Sound board
> (800-3174) and the Zektor Sound board (800-3249) I've found a few
> components which have different values for each board, these are listed
> below. The Eliminator snd bd has the reference designations silkscreened
> on the board so locating the components is fairly easy.
>
> Ref Des ELIMINATOR ZEKTOR
> R5 10K 4.7K
> R9 33K 12K
> R71 270K 100K
> R79 2 MEG unused
> R122 220K 390K
> R132 220K 100K
> C9 0.01uF 0.0047uF
> C46 0.022uF 0.047uF
>
> Now about the missing sounds. The disassembly shows that all four
> registers on the board (3C, 3D, 3E and 3F) are accessed. I haven't
> looked real hard at the data being put in them but the very fact that
> they're all accessed means that the AY-3-8912 should be present. This
> MAY account for the few missing sounds. I don't have one of these to
> try out. Mark, do you?

David,

You found out exactly what I found out this weekend.

While Eliminator works fine without the AY-3-8912, I ran across one of my
boards that actually had one of these chips in it and it dawned on me...does
Zektor need this??

Sure enough, I populated by the Eliminator sound board in my Zektor with this
chip and the missing sounds were now present! The mystery is solved!

Now I've got to update my FAQ again :-(

________________ ______ ___ _____ __
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Mark Jenison / __/ /_/ / / / | // | / |__ __/ _ /__ \
jenison@cig.mot.com /___/___/_/_//_/_/_/|_//__|/__| / / / // / /
Sega XY FAQ author /_/|_| /_/ /____/_/|_|
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Received on Mon May 5 07:13:52 1997