PC/XE lockup under DOS

I am running a PC/XE 8-port serial card configured at 9600 baud with polling only. This system is running under MS-Dos. If the system is booted and characters are sent to port 1 before the boot-up completes, the port is unusable. In fact, the application locks up as soon as the port is accessed for a read string call. We are using the DOS int-14 call for clearing the port and reading a string. These calls will work with the older DIGI COMM/XI boards but has stopped working with the PC/Xe boards. Why? Also, the int-14 calls to read character by character do not show this problem. Any ideas?

use older digiboard drivers 94 version works with this problem The 97 version drivers don’t work with the newer boards but work fine with the older ones