Topic
4 replies Latest Post - ‏2013-05-17T06:30:37Z by BillWoodger
BillWoodger
BillWoodger
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Pinned topic V5.1 Base Locators

‏2013-05-13T16:35:04Z |

I am trying to wait for the documentation...

I was reminded of a comment I saw from Tom Ross about the possible extinction of BLLs (and presumably other Base Locators).

Has this happened? Currently there may be up to 32,000+ "Base Locators" per SECTION, if they remain that would be up to 500,000+, or 1 meg of Base Locators per 2GB. I remember when BLLs used to be loaded individually after the CALL to a program, at least now it is in a loop.

So. Are they there?

  • Tom.Ross
    Tom.Ross
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    Re: V5.1 Base Locators

    ‏2013-05-16T18:16:20Z  in response to BillWoodger

    In most cases you will need only 1 BLL per Linkage Section GROUP, we now use relative addressing instructions, no need for a locator for each 4K of data!  The loop that sets BLLs for large GROUPs passed as parameters is now a thing of the past.

    Tom

    • BillWoodger
      BillWoodger
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      Re: V5.1 Base Locators

      ‏2013-05-16T22:45:26Z  in response to Tom.Ross

      Thanks Tom, nice to know. I guess the "some cases" (residue after removing "most cases") would be where there are defined data items beyond 4K, rather than an OCCURS which just extends across several/many 4K areas?

      • Tom.Ross
        Tom.Ross
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        Re: V5.1 Base Locators

        ‏2013-05-17T03:30:22Z  in response to BillWoodger

        The 'some cases' are cases where data items are larger than can be addressed from one long displacement addressing instruction.  That would be data items larger than 2**20 or 1048576 bytes (rather than the typical limit of 2**12 or 4096 bytes.  We still need to calculate pointers for SS instructions like MVC, but we don't maintain a lot of BLL cells like we used to.

        Tom

        Updated on 2013-05-17T03:32:12Z at 2013-05-17T03:32:12Z by Tom.Ross