Robelle Products and MPE/iX 6.5

If you plan to upgrade to MPE/iX 6.5, please take the time to review these notes. MPE/iX 6.5 includes radical changes to the file system to support files larger than 4Gb. The Express 2 release also includes a new version of Image C.09.00 that supports datasets greater than 80Gb. This is definitely a new area for everyone.

Robelle is very interested in contacting any of our users who will be using our products with files greater than 4Gb or datasets greater than 80Gb. Regular system users who will not be using the large files and datasets should have no problems.

We have tested and recommend the following versions of Robelle software for MPE/iX 6.5:


We recommend you use Qedit version 4.8.01 or later for MPE/iX 6.5. If your Qedit maintenance contract has not expired, you would have received this version in the first quarter of 1999. We have not tested previous versions of Qedit against MPE/iX 6.5.

Qedit 4.8 has support for larger-than-4Gb files. The only problem we expect is the line number limit of 8 digits (i.e. 99,999,999 lines). Users may need to set the increment down to the minimum of .001 using the command "set inc .001"


We recommend you use Suprtool version 4.3 or later for MPE/iX 6.5. If your Suprtool maintenance contract has not expired, you would have received this version in the second quarter of 2000. We have not tested versions of Suprtool prior to 4.2 with MPE/iX 6.5. If you plan to use the larger Image C.09.00 limits, you need 4.3.03 or higher.

The following are some important issues to note:

  • Although large files are capable of 128Gb, Suprtool, Suprlink and STExport have been tested with files only up to 20 Gb. We have sorted, linked and exported a 20Gb file.

  • Keep in mind that only fixed-length and KSAM64 files are capable of greater-than-4Gb. Therefor some types of tasks in Suprtool can not work with greater than 4Gb files. For example, with STExport a task with Columns None (resulting in a variable length file), with an Input source greater than 4Gb will fail on the Output command.

  • Starting with MPE/iX 6.5 Express 2, a new version of IMAGE C.09.00 is available. This version of IMAGE now supports 1,200 items, 240 datasets and 64 paths from a master dataset. The previous limits for a master were 1,023 items, 199 datasets and 16 paths. Suprtool 4.3.03 supports these higher limits.

  • IMAGE C.09.00 also supports datasets larger than 80 GB. In order to do this, the IMAGE label was changed to keep track of records and the pointers that hold them together. Prior to version C.09.00, IMAGE stored records in what is known as Entryname format. This format consisted of 32 bits, in which the first 24 bits represented the block number and the last 8 bits represented the position of the record within the block. This format limited the size of datasets to 80 GB, which is the largest number of blocks that you can store in the 24 bits.

    In IMAGE version C.09.00 and later, you can now select a new option called the Entrynumber format. Although this format still uses 32 bits, it does not represent the block and position within the block, but rather a record number.

    Suprtool 4.3.03 has been enhanced to support this new internal change to IMAGE. Note that HowMessy currently returns an error when you attempt to report on a dataset with this feature enabled, because the block number calculations are no longer relevant for this type of database.

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