++USERMOD(ZP60005)       /* IOS SIO COUNTERS */  .
++VER(Z038) FMID(FBB1221) PRE(UZ68196)
 /*
   PROBLEM DESCRIPTION:
     IOS DOES NOT MAINTAIN CHANNEL AND DEVICE SIO COUNTS BY DEFAULT.
       THE HALFWORD WRAP-AROUND SIO COUNTERS FOR CHANNELS (IN
       THE CHANNEL AVAILABILITY TABLE) AND DEVICES (IN THE UNIT
       CONTROL BLOCK COMMON EXTENSION) ARE NOT MAINTAINED UNLESS
       MF/1 IS ACTIVE.  MF/1 ACTIVATION AND DEACTIVATION OVERLAYS
       THE "HOOK" INSTRUCTION WITH AN APPROPRIATE INSTRUCTION.
       BY REPLACING THE DEACTIVATION INSTRUCTION WITH THE ACTIVATION
       INSTRUCTION, SIO COUNTS WILL BE MAINTAINED AS SOON AS NUCLEUS
       INITIALIZATION DISABLES I/O TRACE.  FURTHER, BY REPLACING THE
       ASSEMBLED "HOOK" INSTRUCTION WITH THE ACTIVATION INSTRUCTION
       SIO COUNTS WILL BE MAINTAINED FROM THE START OF THE IPL.  TO
       COVER ALL POSSIBILITIES, THE I/O TRACE HOOK IS ALSO CHANGED
       SO THAT THE SIO COUNTER CODE IS NOT BYPASSED IF AN I/O TRACE
       IS PERFORMED.

       THIS USERMOD UPDATES THE ASSEMBLED HOOK INSTRUCTION AND THE
       MF/1 DEACTIVATION INSTRUCTION IN IOS TO MATCH THE MF/1 IOS
       ACTIVATION INSTRUCTION.

   SPECIAL CONDITIONS:
     ACTION:
       AN IPL MUST BE PERFORMED FOR THIS SYSMOD TO BECOME ACTIVE.

   COMMENTS:
     PRYCROFT SIX P/L PUBLIC DOMAIN USERMOD FOR MVS 3.8 NO. 5.

     ORIGINALLY FOR UZ64419 (DEC 2001).
     THIS REWORK FOR UZ68196 (NOV 2002).

     THE FOLLOWING MODULES AND/OR MACROS ARE AFFECTED BY THIS USERMOD:
     MODULES:
       IECIOSAM
 */.