Question about modems

Nigel Johnson nw.johnson at ieee.org
Wed Nov 13 12:41:08 CST 2019


On 13/11/2019 13:36, Chuck Guzis via cctalk wrote:
> There are other "oddball" combinations, such as 8E1 and 8O1, which sends
> a 9-bit data frame.  You can see datasheets on some UARTs as well as MCU
> UARTs that support the 9 bit packet.
According to the diagram of the Smartmodem there is no UART, the 1488s 
and 1489s go directly to the Z80.
> Also, don't/doesn't TDD (5 level code) use 5E2 or some such.  Same for
> Telex/TWX.

Not sure 5 level code (ITU #2) ever had parity, but to confuse the issue 
even further, there was a 1.5 stop bit option too, for mechanical machines!

cheers,

NIgel


>
> --Chuck

  

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