Thanks for all your responses. Yes, we are fully licensed for RSCS. I realize that the timing could hav e been better, but I didn't order the new release. That was done by my predecessor, who quit suddenly. For legal reasons I can't contact that
person. Regardless, I am now in the situation I'm in. In looking back on our old system, I don't think the exits were re-assembled; rather they were re- linkedited. The TEXT files have a pretty old date, but the EXITLIB LOADL IB is much more recent. The option to use the new FL540 of RSCS came from IBM from an ETR I opened. Not their first piece of advice. This morning I compared my newly-created TEXT files from my assemble and except for the date they are the same, so the assembler seemed to work. I'm fairly certain these exits are in use. I used a tool called Track to look at RSCS virt storage on our 5.2 system, because I was also curious about that. It shows: Base= 0000000000000000 Real address= 00000001B2F99400 Vaddr Offset Hex Ebcdic 0000000000004400 +004400 00000000 10000000 C5E7C9E3 D3C9C240 * EXITLIB * 0000000000004410 +004410 D3D6C1C4 D3C9C240 00000000 00000000 *LOADLIB * The EXITLIB LOADLIB is the customized library. Dave, thanks for pointing me to the Exit manual. I did manage to find th e correct PROFILE GCS on the 5.2 system and it does indeed point to EXITLIB . I'm new enough that I still have trouble locating proper files. The Exit manual also mentions the HLASM several times. Alan, I understan d the reasoning behind using modern assemblers, but I spent more time than I needed to trying to figure out why I couldn't use the one specified in th e manual. Thanks again for your responses. I'll let you know if I have any sort of success.