Int 14 Fn 0B  - Mbbios - Read Buffer                                       [S]

   AH = 0Bh
   CX = size of buffer
   ES:DI -> buffer

Return: AH = composite line status (see #0230) formed by ORing all statuses
         on receive interrupts; bit 0 set if additional characters
         available
   AL = composite modem status (see #0231) formed by ORing all statuses
   CX = number of characters actually read
   DI updated

Note:  the PACCOM version of MBBIOS does not use CX or ES:DI on call,
     instead returning ES set to the segment of the buffer containing a
     received packet, or 0000h if no packets available; the buffer may
     be freed with AH=0Ch"MBBIOS"

See Also: AH=02h,AH=08h"MBBIOS",AH=0Ah"MBBIOS",AH=0Ch"MBBIOS",AH=18h"FOSSIL"