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cbmeeks

UART for TMS9995?

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I'm thinking about wire-wrapping a small TMS9995 board and I have everything except a UART for it.

It seems the TMS9902 is the preferred route.  But all I have are some 65C51's and some modern NXP DUART's.

 

Before I order a (possibly fake) TMS9902 off eBay...wait two months to arrive from China...discover they are fake....rinse/repeat, I was wondering:

 

1) Is there a somewhat reliable supplier of them in the US?  I only need 1 or 2.

 

2) How difficult would using a non-standard TI part be?  Something like the 65C51.

 

3) Something different?

 

All I want to do is run a simple serial monitor and tinker around.

 

Thanks for any suggestions.

 

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I have China 9902s from polida2008 (eBay). I can send you some. I have not tested them yet.

 

You can follow Stuart Connor's design to use any MAX232 (TI even makes them) to make the signal EIA-RS232 levels. Or just get a TTL serial cable ("FTDI") to hook up to the RX/TX/CTS pins.

 

 

Another idea, which I have not got to yet, is to divide down a 8.192 MHz oscillator and match 115,200 baud exactly. The 9902 with a 3Mhz input can't quite get it. Probably safer though, going with the TMS9995 3 MHz clock out and 9600 baud.

 

 

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Thanks for the offer.  I've bought from polida2008 before but have not tested the chips I got from him.  However, I also found a 9902 from a US seller so I went ahead and bought it.  Not sure if that makes much difference but he said he got them as new parts a long time ago. 

 

Thanks!

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