Erik:

In order to support the 93,750 baud system without slowing things down, I would need to convert to the next highest standard rate, which is 115,200 baud. I have been unable to find a single crystal frequency that will support both 93,750 and 115k.

At 12 MHz, 16 MHz and 11.0592 MHz, the round-off in the timer reload value calculations leads to much more than the 2% baud frequency error recommended by Intel for reliable communication. That is why I agreed with the other posters that two processors are needed.

Of course, if there is a way to do it with a single processor, that would be preferable.

I will check at Cypress for USB app. notes. Thanks for the suggestion.

Carroll