Yes, I've switched back to CLI.

Thanks,
Dave Clark


On Mon, Feb 16, 2026 at 4:40 PM Seymour J Metz <[email protected]> wrote:

> The TM instruction only tests Those bits tat have a 1 in the  field. With
> a mask of C4 it is testing bits 0, 1 and 5; it is not testing bit 7. That's
> why it gets the same CC for C4, C5, C6 and C7.
>
>
> --
> Shmuel (Seymour J.) Metz
> http://mason.gmu.edu/~smetz3
> עַם יִשְׂרָאֵל חַי
> נֵ֣צַח יִשְׂרָאֵ֔ל לֹ֥א יְשַׁקֵּ֖ר
>
>
>
>
> ________________________________________
> From: IBM Mainframe Assembler List <[email protected]> on
> behalf of David Clark <[email protected]>
> Sent: Monday, February 16, 2026 2:45 PM
> To: [email protected] <[email protected]>
> Subject: Apparent Test Under Mask Failure
>
>
> External Message: Use Caution
>
>
> Can someone please explain to me how the following fails to drop through to
> the actual test for C5?  The request at d'8000' is 'E' (x'C5', b'11000101')
> but the code is taking the 'D' (x'C4', b'11000100') branch.  Why?
>
> The condition code should result in mixed -- not ones.  Am I going to have
> to change from bit mask testing to 'CLI' testing?
>
> 000872 91C4 8000      00000        1842+         TM
>  REQU_DELETE,L'REQU_DELETE
> 000876 A714 0124            00ABE  1843+         JO    TXTDLET
> ...snip...
> 0008C2 91C5 8000      00000        1994+         TM
>  REQU_2EBCDIC,L'REQU_2EBCDIC
> 0008C6 A714 02D7            00E74  1995+         JO    TXT2EBC
>
> The bit mask flags are defined as follows--using my own macros based on the
> late Dr. John Ehrman's SHARE presentation on the subject.
>
> 000000                              300=TXTREQU  DS    CL1
>                       00000 000C4   308+REQU_DELETE  EQU *-1,C'D'
>                       00000 000C5   310+REQU_2EBCDIC EQU *-1,C'E'
> ...snip...
>
> Sincerely,
> Dave Clark
>
>
>

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