Determine the CPU serial number

To determine the serial number of a specific mainframe, authorization to enter MVS commands is necessary. The command can be entered from the operator console or by using a product like System Display and Search Facility (SDSF).

Issue the MVS command Display Matrix for CPU. The command syntax is shown below. 

D M=CPU

The operating system issues a Store CPU ID (STIDP) instruction, which returns a doubleword (8 bytes, 16 digits) of information. The format of this information is shown.

Table 1. STIDP information format
00 an xxxx mmmm 0000
0 1 2 3 4 7 8 11 12 15
Version Code Logical Partition Identifier (LPID) CPU Serial Number CPU Model Number zeros

The operating system displays the following information:

RESPONSE=TDM1
 IEE174I 09.24.55 DISPLAY M 528
 PROCESSOR STATUS
 ID  CPU                  SERIAL
 00  +                     15D77D8562
 01  +                     15D77D8562
 02  -
 03  -
 CPC ND = 008562.T02.IBM.02.0000000FD77D
 CPC SI = 8562.P05.IBM.02.00000000000FD77D
 CPC ID = 00
 CPC NAME = RP55A
 LP NAME = RALTDM1    LP ID = 15
 CSS ID  = 1
 MIF ID  = 5

The serial number that is displayed is 15D77D8562. Using the preceding chart the CPU serial number maps out to the following information.

  • Version Code is not displayed
  • 15 is the LPID
  • D77D is the CPU serial number
  • 8562 is the CPU model type
  • Zeros are not displayed

The CPC SI field displays the MTM (machine type and model) information.

For more information on the Store CPU ID instruction, see z/Architecture Principles of Operations.