Int 21 Fn 4402  - PC/tcp Ipcust.sys - Reset Configuration Data Read Point  [N]

   AX = 4402h
   BX = file handle referencing device "$IPCUST"
   CX, DS:DX ignored

Return: CF clear if successful
       AX destroyed
   CF set on error
       AX = error code (01h,05h,06h,0Dh) (see AH=59h)

Notes: there are a total of 378h bytes of configuration data for IPCUST.SYS
     version 2.05.  If less than the entire data is read or written,
     the next read/write continues where the previous one ended; this
     call and AX=4403h both reset the location at which the next
     operation starts to zero
   v2.1+ uses a new configuration method, but allows the installation
     of IPCUST.SYS for backward compatibility with other software which
     must read the PC/TCP configuration

See Also: AH=3Fh"IPCUST",AH=40h"IPCUST",AX=4403h"IPCUST"