My guess would be one of the hurdles you have to overcome is having the proper UIM for HCD to access. I recall years ago I had to have a USERMOD to add a UIM to the NUCLEUS so HCD understood a device that was not by default in the UIMs supplied by IBM.
So, one thing you would need is a UIM of the needed device type(s). As was already mentioned you can update the PROFILE information in HCD to point to an alternate library that could contain the UIMs you need. After that I'm not sure what else you might need. The following stuff is from the z/OS 3.1 Hardware Configuration Definition User's Guide. Chapter 3, How to set up, customize and start HCD. UIM UIMs (unit information modules) perform the device-dependent part of the operating system configuration definition. There is a UIM for each supported device or device group. Each UIM recognizes and processes the values coded for its device or device group. HCD routines load all UIMs, either IBM or customer supplied, into virtual storage and make calls to the UIMs. UIM_LIBNAME Specifies the name of the data set containing the UIMs, the associated UDTs, and any help members for the UIMs. If the keyword is omitted, SYS1.NUCLEUS is assumed (Note: only UIMs residing in SYS1.NUCLEUS are read during IPL!). When UIM_LIBNAME is specified, HCD does not implicitly access SYS1.NUCLEUS for loading the UIMs. If you specify an asterisk (*) as data set name, HCD assumes that the UIM data set (including SYS1.NUCLEUS) is part of the ISPF load library concatenation chain, contained in the JOBLIB/ STEPLIB concatenation chain, or specified in the active LNKLSTxx member. You can only define one data set with the UIM_LIBNAME statement. If you want to specify several data sets, specify an asterisk (*) as data set name and specify the data sets in the JOBLIB/STEPLIB concatenation chain. UIM_VOLSER Specifies the volume serial number of the UIM library. Required only if the data set is specified via keyword UIM_LIBNAME and is uncataloged. Paul -----Original Message----- From: IBM Mainframe Discussion List <[email protected]> On Behalf Of Radoslaw Skorupka Sent: Saturday, January 17, 2026 5:50 PM To: [email protected] Subject: Re: Older HCD version As far as I know it is possible to configure HCD to point to alternative library instead of NUCLEUS. However I don't think it is enough. -- Radoslaw Skorupka Lodz, Poland W dniu 16.01.2026 o 20:11, Mark Jacobs pisze: > There are some HCD modules in the nucleus, so depending on what they do/support you might not be able to run an older HCD on an uplevel system. > > Mark Jacobs > > Sent from ProtonMail, Swiss-based encrypted email. > > GPG Public Key -https://api.protonmail.ch/pks/lookup?op=get&[email protected] m > > > On Friday, January 16th, 2026 at 1:03 PM, Radoslaw Skorupka<[email protected] <mailto:[email protected]> > wrote: > >> Is is somehow possible to run backlevel HCD on current system? >> I mean current system, like z/OS 3.1 and HCD which is aware of machines >> like z900 or even older ones. >> I just wanted to check some definitions on the older hardware. >> >> -- >> Radoslaw Skorupka >> Lodz, Poland >> ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] <mailto:[email protected]> with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
