atari email archive

a collection of messages sent at Atari from 1983 to 1992.

Audio Stuff

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	If you are going to design a new Sound Procesor System you
might want to consider some of the things I have done on TomCat.

   1. The TMS 5220C can be reset by bringing /WS and /RS down (and up)
at the same time. Therefore, it does not require a transistor switch 
to remove -5V from the IC. (TMS 5220C is Atari p/n 137308-002.)

   2. The TMS 5220C Clock input will accept an almost TTL level if you tie 
PROUT to +5v. (You must use a pullup resistor on the CLK input so it will go 
up to VSS.) The clock frequency must then be half what it would otherwise be, 
so that for example, 8 KHz sampling requires a 320 KHz clock. 

   3. At Earl's request I designed into it the capability of having the
software be able to select the TMS 5220C Clock frequency so it can
handle 8 KHz or 10 KHz sampling at the programmer's choice.

   4. In order to accomodate more speech memory I have put together a
Sequential Memory. The programmer writes to a location to set the
starting address. There is another location that reads the data thus
selected. Every Read increments the Sequential Memory address. I have
implemented 64K bytes of Sequential Memory (in two 26256's) in addition 
to 32K bytes of Program memory and 8K bytes of RAM. (An 8K x 8 RAM takes
up less board space than two 2k x 8's.)

The above should not be considered an endorsement of the idea of having
a separate Universal Audio PCB.


RE: Audio Stuff

(2 / 2)

Items 1,2 & 3 are already incorporated in Gauntlet hardware. 
You may be interested in comparing schematics. Item 4 is interesting
and I might take a look at what you have done.

Do you agree with the idea of a universal Audio PCB including amplifiers.

Message 1 of 2

Apr 02, 1986