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Date: April 02, 1986 17:17
From: KIM::MARGOLIN
To: MCCARTHY,BRAD,MARGOLIN
Pat, 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. ---Jed
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Date: April 02, 1986 17:22
From: KIM::MCCARTHY
To: KIM::MARGOLIN,MCCARTHY
Jed. 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. Pat.
Apr 02, 1986