Question about modems

Jim Brain brain at
Fri Nov 15 00:58:47 CST 2019

On 11/15/2019 12:37 AM, Jim Brain wrote:
> Looks like there might be a few more corner cases as well.  Maybe 
> modems did not accept mixed case.  AT and at seem to work fine... 
> Anyone have a modem handy to check?

Spoiler alert... They do not.  Only 'at' and 'AT' are recognized.  So, 
bit 5 of both chars must be the same for the command to be handled.


Jim Brain
brain at

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