8251 troubles

[Alexis]

On Sun, 2008-04-27 at 08:23 -0700, dwight elvey wrote:
> Hi
>  I've got a funny problem with a 8251.
>  I've been writing 8080 code and seem to have a strange
> problem.
>  I initialize the chip in async mode. I have a light box on the
> serial wire. It is initialized to both send and recieve.
>  I send one character to the 8251 and it passes it to the software
> on the 8080 side. I display it on the 8080 side.
>  I then send another character to the 8251. Nothing happens.
> It won't receive until I reset it.
>  None of the status lights change. I can see the data light flicker.
>  It could be a bad part but it just doesn't seem that it would
> work once and then fail to work for the second character.
>  It just doesn't make sense.
>  Is there something I'm missing about the 8251.
> Dwight
> 

That could be caused by a lot of things. Could you post the relevant
code?