While we are on the topic of serial communication could anybody tell me if the Interrupt enable byte of the 16550 UART(on the PC side) can be read?

I was having problems using the C function inportb(0x3f9); to read hte Interrupt Enable register on the PC side of the serial link. I have to add a delay and wait for the uc to respond. i am unable to read the IER byte and then decide if it is time to read the byte transmitted by the uc. If I initialize the IER then there is no change even after transmission and after reception! I was able to make a two way communcation using the delay idea though. But that would not be duplex in the true sense.

DLAB was set to zero before reading from 0x3f9

base address for com1 is 0x3f8 (in this case)

cheers,

Sushil