I'm back onto this problem. I wrote a proof-of-concept program and it works. I've modified an existing z/OS product and my changes don't work.
Only DSNAME and DISP are coded on the DD statements. 1st file is VB with LRECL=200 2nd file is VB with LRECL=230 3rd file is FB with LRECL=1000. Proof-of concept : It is AMODE 31, RMODE ANY and re-entrant. It's save area/working storage is in 31-bit storage. DCB before OPEN 09.18.12 JOB13853 +00006EB0 00000000 00000000 00000000 00000000 00000000 00000001 00004000 00000001 09.18.12 JOB13853 +00006ED0 00006F3A 00000000 C9D5D7E4 E3404040 0A004800 00000001 00000001 00000000 09.18.12 JOB13853 +00006EF0 00000000 00000001 00000001 00000001 00000000 00000001 00000000 00000001 DCB after OPEN 09.18.12 JOB13853 +00006EB0 00000000 00000000 01D00000 00F43026 002FE5A2 05007C70 00004000 00006CB8 09.18.12 JOB13853 +00006ED0 02006F3A 50006F10 00404800 008C5D84 1AE30E68 00CA99F8 0A000001 020903E8 09.18.12 JOB13853 +00006EF0 30013030 00006D28 00000000 00000000 000000C8 00000000 00000000 80E37A58 DCB inside of OPEN exit prior to a reread (GET) 09.18.12 JOB13853 +00006EB0 00000000 00000000 01D10000 00F43026 002FE5A2 05007978 00004000 00006CB8 09.18.12 JOB13853 +00006ED0 02006F3A 50006F10 00544800 008C508C 1AE30E68 00CA99F8 0A000001 0209047E 09.18.12 JOB13853 +00006EF0 30013030 00006D28 00000000 00000000 000000E6 00000000 00000000 80E37A58 DCB inside of OPEN exit prior to a reread (GET) 09.18.12 JOB13853 +00006EB0 00000000 00000000 01D50000 00F43026 002FE5A2 050070A0 00004000 00006CB8 09.18.12 JOB13853 +00006ED0 02006F3A 90006F10 00684800 008C6894 1ACAC000 00CA99F8 0A000001 02096978 09.18.12 JOB13853 +00006EF0 30013030 00006D28 00000000 00000000 000003E8 00000000 00000000 80E37A58 ISV product : The program that doesn't work is not re-entrant and runs in AMODE 31 but is RMODE 24. Its save area/working storage is in 24-bit storage. One can see that the DCB prior to the reread does not have the attributes of the 2nd dataset namely LRECL=230 and BLKSIZE=1150. DCB before OPEN 00011018 0 00000000 00000000 00000000 00000000 00000000 00000001 00004000 00000001 *....................... .. .... * 00011038 20 00012580 00000000 C6C9D3C5 C1404040 0A004800 00000001 00000001 000003E8 *. ....FILEA . .... ... .. Y* 00011058 40 00000000 00000001 00000001 00000001 000000C8 00000001 00000000 00000001 *....... ... ... ...H... ....... * DCB after OPEN 00011018 0 00000000 00000000 01D00000 00F43026 002FE5A2 05028C70 00004000 000252D0 *........ }...4 . Vs .. .. }* 00011038 20 02012580 500112D0 00A44800 008C4064 1AE30E68 00CA99F8 0A000001 020903E8 * & }.u .. T . r8 .. Y* 00011058 40 30013030 00025340 00000000 00000000 000000C8 00000000 00000000 80E37A58 * . ...........H........ T: * DCB inside of OPEN exit prior to a reread (GET) 00011018 0 00000000 00000000 01D10000 00F43026 002FE5A2 05028C70 00004000 000252D0 *........ J...4 . Vs .. .. }* 00011038 20 02012580 500112D0 00B84800 008C5A6C 1AE30E68 00CA99F8 0A000001 020903E8 * & }. .. !% T . r8 .. Y* 00011058 40 30013030 00025340 00000000 00000000 000000C8 00000000 00000000 80E37A58 * . ...........H........ T: * I see the SVC 37 entry in the system trace table but no corresponding SVCR 37. Then abend S001-4. CPU STATUS: BLS18058I Warnings regarding STRUCTURE(Psa) at ASID(X'0001') 00: BLS18300I Storage not in dump PSW=07541000 00000000 00000000 00DAB422 (Running in PRIMARY, key 5, AMODE 24, DAT ON, SUPERVISOR STATE) Disabled for PER ASID(X'001A') DAB422. IGC0005E+1422 IN PLPA ASCB26 at FB5D00, JOB(TH127153), for the home ASID ASXB26 at 8FD000 and TCB26E at 8D2AA0 for the home ASID HOME ASID: 001A PRIMARY ASID: 001A SECONDARY ASID: 001A General purpose register values Left halves of all registers contain zeros 0-3 84000000 84001000 008C40EB 00DAB438 4-7 008C4420 008C4474 008C4428 008C40B0 8-11 008FF708 008CA088 00F4DF78 008C5A6C 12-15 008C45E4 00027988 80DAB328 00000004 Access register values 0-3 008FB37C 00000000 00000000 00000000 4-7 00000000 00000000 00000000 00000000 8-11 00000000 00000000 00000000 00000000 12-15 00000000 00000000 00000000 00000000 Control register values 0-1 00800002_9F98EE20 00000000_7BE08007 2-3 00000000_151A0700 00000002_00C0001A 4-5 00000002_0000001A 00000000_7EEF4680 6-7 00000000_00000000 00000000_7BE08007 8-9 00000000_00000000 00000000_00000000 10-11 00000000_00000000 00000000_00000000 12-13 00000000_057E93E7 00000000_7BE08007 14-15 00000000_DF8FEEF3 00000000_7F670010 Apologies for the staggered display. Any help would be appreciated. Regards, Pierre. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN