RE: Amplifone yoke

>Wow, Thats makes two of us. Come on Clay now you have to do it.
> If not for us, do it for yourself
 
Heheh... Yeah, it does need to be done! I can't make any promises on the
timeline yet, but maybe I'll try to get some schematics captured this fall
at least. Usually I have a bit of a break in early summer, but with the
economy being slow I decided it was probably wise to take more contracting
jobs than I normally would have. (Better to have too much work to do than
to be kicking myself for turning down biz if things didn't start to
recover...)
 
Unless anyone has a better idea, I still think the thing to do is:
 
1) keep the speech board and just bank switch the ROM (or maybe move the
chips over to the 'new' sound PCB). Probably easier/cleaner to just move
the speech MCU and Orator over to a new board with a larger bank selected
flash and some decode logic.
 
2) plop down a little ARM7 with an external address bus and a bunch of NOR
flash to store samples and maybe a serial DAC for audio output (could
probably bitbang I2S or something for a nice, modern stereo DAC).
 
3) maybe add a litttle glue logic to fully decode write accesses to the
sound ports and just present the data to the ARM in an easy manner.
(Instead of needing to have the ARM monitor the bus and pull transactions on
the fly-- it's fast enough, but since I have a gazillion (I counted 'em)
PALs and CPLDs around here that's one less thing to mess with and debug in
software.)
 
I can picture the ARM being a daughterboard for the existing speech board
and just tapping in to the bus and audio, but it's taken this long already,
so doing something half-assed seems lame. I'm thinking a custom card that
just plugs into the G80 backplane. Might not need to be full length to help
keep the cost down.
 
We could also just require the user have a Universal Sound Board and skip
the need to have samples of all the TS/ST sounds. That'd reduce flash
requirements for the ARM and keep more "original" sounds. Of course it also
keeps the original reliability on the USB too. ;-) Guess that could just be
an option-- same hardware would work either way.
 
Anyway, something to mess with during the rainy season here. ;-)
 
-Clay

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Received on Thu Oct 1 14:24:31 2009