Int 14 Fn 08  - Digiboard Digichannel Pc/x* - Alternate Status Check       [S]

   AH = 08h
   DX = port number (00h-03h) (04h-43h for XAPCM232.SYS)

Return: AH = RS232 status bits (see #0230 at AH=03h)
   ZF set if no characters queued
   ZF clear if character available
       AL = next character

See Also: AH=03h,AH=08h"PC-MOS",AH=09h"Digiboard",AH=14h"Digiboard"