Int 2F Fn 8002  - Cs_tsr Specification - Get Process Block By Process Han  [t]

   AX = 8002h
   BX = process handle for TSR (see AX=8001h"CS_TSR")

Return: ES:DI -> process block for specified TSR (see #2614)
       unchanged if no match for process handle

Note:  This function is used to allocate a process handle when the TSR
     installs itself, by setting ES:DI to point at something other than
     a CS_TSR process block's signature string and iterating through the
     possible process handles (0001h to FFFFh) until ES:DI is returned
     unchanged

See Also: AX=8000h"CS_TSR",AX=8001h"CS_TSR",AX=8003h"CS_TSR"