At 10:05 PM 2/11/02 -0500, you wrote: <snip> (original poster)
I must use 5726, 5760 and 9600. My app need this to work. On 4800 and 9600 I got error.
<snip> (Lawson)
Now nobody is going to convince me there is any software that will make a normal 16550a run at 5726
<snip>
You still don't have access to the world wide web ? If you have access to Google, search for the following Usenet posting, for example :
UnHy6.600095$JT5.16435354@news20.bellglobal.com
If you can't use Google, you could see that this is a common request under Windows. quite a few programmers need to access devices with non-standard crystals, or even non 8251 chips with specific drivers. In this post, you could see that SetCommState accepts any baud rate up to 9600 bauds, and that over 9600 bauds the idea is that the Windows driver should accept values that are inside a +-1% interval of the 'correct' value (although the poster says that the calculation is bugged and works only for negative differences).
The Windows code for the 8251 family is probably always rounding to the next integer value under 9600, and if the wanted rate falls to +-1% of the 'normal' value over 9600. As I understand it, the 1% tolerance is explained because such a small difference don't matter for asynchronous serial communication.
Gerard