DTFCP was unsupported for customers but used internally by IBM. The CP stands for "compiler." It was like DTFDI but with a lot more flexibility. Now that IBM no longer ships source code perhaps they no longer ship DTFCP. Is there anywhere you can rummage around like some "auxiliary" macro library?
DTFPH? DTF Physical? Is it like EXCP only a little easier to use? You know, this is really not an "assembler language" question. You know how to code assembler; you just don't know what logic to code. It's really an application logic/OS interface question. Why don't you post it in IBM-MAIN and/or the VM list? IBM-MAIN is in theory not z/OS only, and there may be some VSE folks on the VM list. You might get lucky and get an oiff-list reply from someone who actually knows how LIBR does it. Charles -----Original Message----- From: IBM Mainframe Assembler List <[email protected]> On Behalf Of David Clark Sent: Sunday, December 14, 2025 2:04 PM To: [email protected] Subject: Re: [External Sender] Re: Reading Past /* on SYSRDR/SYSIPT Note: I didn't use DTFDI because it restricts record length by device type (80, in the case of SYSRDR/SYSIPT). REXX source lines can be longer than 80 so that is why I was using DTFCD. Sincerely, Dave Clark -- int.ext: 91078 direct: (937) 531-6378 home: (937) 751-3300 Winsupply Group Services 3110 Kettering Boulevard Dayton, Ohio 45439 USA (937) 294-5331 On Sun, Dec 14, 2025 at 4:57 PM David Clark <[email protected]> wrote: > >> Does DTFCP still exist? > > I haven't heard of DTFCP. DTFDI gives device independence. The > following are all the DTFs I found on the system. > > DTFCD > DTFCN > DTFDA > DTFDI > DTFDU > DTFIS > DTFMT > DTFPH > DTFPR > DTFSD > DTFSR > > > Sincerely, > > Dave Clark > -- > int.ext: 91078 > direct: (937) 531-6378 > home: (937) 751-3300 > > Winsupply Group Services > 3110 Kettering Boulevard > Dayton, Ohio 45439 USA > (937) 294-5331 > > > On Fri, Dec 12, 2025 at 6:39 PM Charles Mills <[email protected]> wrote: > >> FWIW, Google AI sez >> >> In IBM VSE, trying to read a sequential file (like a card reader >> input >> stream) past the end-of-file (EOF) marker will result in an error or >> an exception. You cannot "read past EOF" in the conventional sense of >> retrieving more data, because no more data exists. The standard >> approach is to detect the EOF condition and stop reading. >> >> I recall doing something like this but it was literally 50 years ago. >> >> The problem is complicated because there is no real card reader (I >> assume :-/). When I did it there was a real 2540, but the program was >> actually reading from POWER, not from the card reader. That ship had already >> sailed. >> >> I have no experience with VSE in the post-card-reader era. How do you >> submit the job? From CMS via a virtual card reader under VM? >> >> Does DTFCP still exist? It was a badly-kept IBM secret that gave you >> DTF device-independence, and more flexibility than any of the >> supported DTFxx macros. >> >> Charles >> >>
