Tony, Wouldn't that be documented in the hardware manual for the specific DASD control unit being accessed? I haven't had need for any of those since 3330/3350 days, but I am sure they must exist somewhere for all of the 3390-look-alike units, both IBM and competitors.
Of course, I just realized that I AssUMed your customer is trying to access DASD - could it be a virtual tape library command of some kind? Again, I would assume the VTL hardware manual would document the command codes accepted. Peter -----Original Message----- From: IBM Mainframe Assembler List <ASSEMBLER-LIST@LISTSERV.UGA.EDU> On Behalf Of Tony Thigpen Sent: Thursday, May 11, 2023 6:54 PM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: IO CCW command codes? EXTERNAL EMAIL I don't know if it should be on this list, or IBM-Main, but I am looking for some good documentation on current command codes used in CCWs. For example, I am helping a customer with a issue with VSE cause by a vendor program that is using a command code of 'A5' and I can't find A5 in any of my manuals. I would even be willing to pay some nominal fee to IBM for a 'non-disclosure' document on this subject if needed. Tony Thigpen This message and any attachments are intended only for the use of the addressee and may contain information that is privileged and confidential. If the reader of the message is not the intended recipient or an authorized representative of the intended recipient, you are hereby notified that any dissemination of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by e-mail and delete the message and any attachments from your system.