If the REQU_DELETE byte contains x'C5' then all of the bits corresponding to the 1 bits in your mask are in fact ones, so a branch specified by JO will be taken. It isn't clear if you want CLI instead.
- mb > -----Original Message----- > From: IBM Mainframe Assembler List <[email protected]> On > Behalf Of David Clark > Sent: Monday, February 16, 2026 2:46 PM > To: [email protected] > Subject: [EXTERNAL] Apparent Test Under Mask Failure > > 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
