The op code has two halves which are not contiguous. The first half is the E3. The second half is the 17 in the right-most byte. It's called Load Logical Thirty-One Bits. It's not secret. Bill Fairchld
----- Original Message ----- From: "Alan Field" <alan_c_fi...@bluecrossmn.com> To: IBM-MAIN@LISTSERV.UA.EDU Sent: Wednesday, July 16, 2014 12:55:47 PM Subject: Re: "Secret" Machine Instruction? Coded this and assembled it: TEMP CSECT DC X'90ECD00C' DC X'188D' DC X'E3D0021C0017' DC X'07FE' END Loaded it under TEST and listed the instructions: TEST l t i l(32) T +0 STM R14,R12,12(R13) +4 LR R8,R13 +6 LLGT R13,540 +C BCR 15,R14 Alan Field Technical Engineer Principal BCBS Minnesota Phone: 651.662.3546 Mobile: 651.428.8826 From: "Chase, John" <jch...@ussco.com> To: IBM-MAIN@LISTSERV.UA.EDU, Date: 07/16/2014 12:40 Subject: "Secret" Machine Instruction? Sent by: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> Hi, List, While browsing around looking for something else, I noticed in an IBM-supplied load module the following sequence at the entry point: 90EC D00C 188D E3D0 021C 0017 WTH is 'E3D0' ?? It seems to be missing from the "List of Instructions by Op Code" in the 10th edition of z/Architecture Principles of Operation, published September 2012. TIA, -jc- ********************************************************************** Information contained in this e-mail message and in any attachments thereto is confidential. If you are not the intended recipient, please destroy this message, delete any copies held on your systems, notify the sender immediately, and refrain from using or disclosing all or any part of its content to any other person. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
