tip week 26/2001:

It sometimes happens that you would like to know, when a certain LOAD module was created. In other cases you just like to know if two LOAD modules with the same name in two different libraries are copies of each other. LOAD modules are timestamped. Therefore it is fairly easy to find the creation date and time.

The authorized way of finding the timestamp is by using the IBM supplied program called AMBLIST. This program can produce a lot of information about a LOAD module and among this information is the date and time when the LOAD module was linkage edited (created). AMBLIST is described in the manual called MVS diagnosis: Tools and service aids. The following piece of JCL prints the date of linkage editing on SYSPRINT for the LOAD module MYLOAD located in dataset MY.LOAD.MODULE:

//SYSIN    DD *

The step not only prints the date, but a lot of other information. It can be a hard job to find the timestamp, but if you look for the text "THIS LOAD MODULE WAS PRODUCED BY..." you will find it. All this job submission and searching is redundant if you skip directly to the ISPF browser and the use of the HEX ON command. This brings us to the unauthorized way of finding the timestamp.

Assuming that you have started an ISPF browse session on the LOAD module in question you can start executing the primary command HEX ON. Then you execute the command FIND X'80FA01' FIRST. This hexadecimal string is located in the record before the record containing the timestamp. In this record the date starts in position 16 and is a packed decimal julian date. Here is an example:

ü..5695DF108 ..q.È....

The first record is the record containing the hexadecimal search string. The next record contains the date in position 16. The julian date is 98289. The year is 1998 and it is day number 289, whatever day that was. You can find out for yourself. AMBLIST also produces the julian date, so this is no releif. The packed field following the date is the time of day. This LOAD module was produced 11.00.16. In older LOAD modules the time will not be present. The information 5695DF108 refers to the version of the linkage editor, which produced the load module. It is an IBM product number for internal use and it will vary over time depending on various upgrades of MVS.

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