My only question is when submitting a batch job to execute rmode 64 what is the 
value 

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> On Aug 17, 2025, at 10:32 AM, Peter Morrison 
> <[email protected]> wrote:
> 
> People,
> 
> 
> 
> I have watched this discussion for several days.  I thought I would weigh
> in. I have created and executed programs in RMODE 64.
> 
> 
> 
> RMODE 64 has been supported by z/OS for a long time. I am not sure what
> level it came in with (someone else can provide that) but all the relevant
> items have been changed, as mentioned below.
> 
> 
> 
> Note that before I begin to list things, to execute in an RMODE 64
> environment (i.e., located above the 'bar') you *MUST* be in AMODE 64 (if
> you are not sure why, please read the principles of operation. You *MUST*
> also remain in AMODE 64 for as long as the code that is being executed is
> above the bar.
> 
> 
> 
> *         You can use the assembler to create a CSECT that can be loaded
> into 64-bit storage by using the '<csectname> RMODE 64' statement.  
> 
> 
> 
> *         There is no specific 'xD' ESD entry. Instead, the object format
> has been enhanced to add a bit to the flags field in the ESD which says 'add
> 4 to the length of the field'.   Thus VD and external AD fields can be
> handled. Similarly, the object RLD records also have a flag bit that says
> 'add 4 to the length - allowing an RLD entry for an 8-byte xD. Note that you
> do not need to use GOFF to have RMODE 64 CSECTs.
> 
> 
> 
> *         When you bind (link-edit) the program, you can specify the binder
> option via the JCL Parm field (you can also use an input option, not
> discussed here, read the manual). *DO NOT* use 'RMODE=64'. Instead you
> *MUST* specify 'RMODEX=64TRUE'. Don't ask me why (RTFM). The resulting
> program is an RMODE64 program.
> 
> 
> 
> *         Note that an RMODE 64 program *DOES NOT* have to be a program
> object. The load module format in a PDS (not a PDSE) has been enhanced, The
> RMODE in the directory entry has a RMODE64 bit, the CESD entry flags in the
> actual load module have a 'add 4 to the length' bit, and the RLD entry flags
> in the actual load module have a 'add 4 to the length' bit.
> 
> 
> 
> *         Program management was enhanced to load RMODE 64 programs above
> the bar. The CDE (still in 24-bit storage) will point to a CDX which point
> to a 64-bit extent list, which has 8-byte addresses and lengths.
> 
> 
> 
> *         The ATTACH[X], LINK[X], XCTL[X], and LOAD facilities all can load
> RMODE 64 programs. Whether the parameter list passed to that program will be
> correct is another matter (note that the parameter list format depends on
> the AMODE, not the RMODE) - the system doesn't alter the passed R1 value so
> you probably need to specify the correct parameter list format - determining
> the target's RMODE (or AMODE) will be fun! (you can't use BLDL, because the
> target program could be in the DLPA). I don't know what happens (IPL wait or
> ignored) if an RMODE 64 program that is put into PLPA (or MLPA or FLPA) -
> there is no  64-bit xLPA (the DLPA can have RMODE 64 programs in it but is
> not built during IPL) and the compressed extent list in the LPDE does not
> have 8-byte addresses and lengths. Note that all RMODE 64 programs *MUST* be
> AMODE 64 but the reverse isn't true. (the parameter list format is based on
> the AMODE of the target, not the RMODE)
> 
> 
> 
> *         The JCL EXEC statement can execute an RMODE 64 program by simply
> specifying its name. I don't know whether or not the PARMS passed are in the
> correct format for a AMODE 64 program (does anyone want to test that?).
> Under the covers the EXEC statement uses ATTACH[X].
> 
> 
> 
> This list doesn't cover everything, but hopefully covers the main things.
> 
> 
> 
> It's pretty easy to make a program execute in RMODE 64 (as mentioned above,
> you *MUST* be in AMODE 64). However, as others have mentioned, only some
> system services allow a user to be in AMODE 64, and even fewer allow a user
> to be located above the bar (i.e., RMODE 64). The safest rule is to assume
> the AMODE64 and RMODE 64 code cannot use a service unless that service
> explicitly says it can.
> 
> 
> 
> Peter Morrison
> 
> 
> 
> 
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