I have been unable to get COM 4 to work - diagnostic programs such as msd show
nothing installed.  I think the software options are OK - is there a known
hardware conflict and/or workaround for this problemand CD ROM
System is a G2K 486DX2/66 tower with ATI video card
Ports are set as follows 
  On board COMa = COM1 IRQ4 to external device
  Internal modem = COM 3 IRQ5
  DFIO port card primary port = COM 2 IRQ3  mouse
  On board COM B = COM 4 IRQ 9  <--- DOES NOT WORK
I have run this from a boot disk with only command.com to eliminate softwar