[GreenKeys] Running 45.45 baud from a USB port - a solution

[John Nagle]

    I now have a way to run 45.45 baud, 5 bits, 1.5 stop bits
from a USB port using devices in current production.

    You need a USB to serial converter based on the Silicon Laboratories
CP2102 chip, which is a single-chip device for converting USB to serial.
I bought the evaluation board for that part:

https://www.silabs.com/products/mcu/Pages/CP2102EK.aspx

This is $29, including board, driver disk, and cables,, but without
a case.

This, plugged into a Windows machine, will become a COM4 port.

It will not, as delivered, run at 45.45 baud.  To do that, it has
to be reconfigured.   Here are the instructions:

https://www.silabs.com/Support%20Documents/TechnicalDocs/an205.pdf

and the program for setting baud rates

https://www.silabs.com/Support%20Documents/Software/AN205SW.zip

This device only does a fixed set of baud rates, unlike regular
serial ports.  But you can change the mapping between requested
baud rate and actual baud rate.  I set 600 baud to map to 45 baud.

This configures the device semi-permanently, so once that's set,
you can use it anywhere.

This has been driving my Teletype Model 15 for the last hour.

Any consumer-type USB to serial adapter that has the SiLabs
CP2102 chip inside can probably be used in this way.

				John Nagle