Yes, you need PoOps to determine what format each instruction has, but the actual syntax of each field is documented only in the HLASM reference manual.
________________________________________ From: IBM Mainframe Assembler List <[email protected]> on behalf of Gary Weinhold <[email protected]> Sent: Thursday, June 29, 2023 11:27 AM To: [email protected] Subject: Re: HLASM religious texts, was Variable symbol without leading & The PoOp manual has always gone beyond the hardware definitions of machine language instructions to provide the symbolic format in HLASM (and its predecessors) of each machine language instruction, e.g., MVC D1(L,B1),D2(B2). There could be many other zSeries assemblers (I don't know of any) that do not use the symbolic format documented in the PoOp to create those machine language instructions. HLASM relies on the PoOp to document the symbolic format of zSeries insructions. When we code in that format, we rely on HLASM to convert the code into machine language instructions. Otherwise we'd have to code machine language instructions as constants, either directly or in macros. It appears that the PoOp, by documenting the HLASM symbolic format of instructions, is a critical and necessary supplement to the HLASM Reference manuals. Since AFAIK HLASM only supports IBM's zSeries (and predecessors) hardware, it would be close to useless without the PoOp. Gary Weinhold Senior Application Architect DATAKINETICS | Data Performance & Optimization Phone:+1.613.523.5500 x216 Email: [email protected] Visit us online at http://secure-web.cisco.com/1ndcMZTfeISGrp8uEhbfCGuxvypenFIsth9o2h0QwGHoN93zUooDFVOvibVmJmLsA0VgDW5PhXR_TD0bH5n3A4G8Uc63ezdZVnjJayudzugHySXLIXM8dt1CpmRVifPIBhP8-AAKhT45j_lWFNUAo7H0UodkmASX8SOiVmUcbTw_MJ8wxXfu_zuH2sAnW_vvH8y3hgQ5Ix7WQz5w9LYbWFxrNqnX-k_MWqslEKVeA1DPKhHQdu9qbW8DaStYX0LhSWy8rEOQA1N13HuPVDJspZOZbGeyTajXptTMu0kByg-R0RCjAgL8NSEkFDVMlbuUNLbRHvVZE8AT3MjQ4K_Nkgc-iYoQouhr_NYBRG4nTVIFqRTPRnRQjQT7m37KrSq9Of_ah85Chj92HXyKf4aZ0LBmCJobfPS1vdR6p9vz-scY5rBOetedo8zpcXrW5pID2/http%3A%2F%2Fwww.DKL.com E-mail Notification: The information contained in this email and any attachments is confidential and may be subject to copyright or other intellectual property protection. If you are not the intended recipient, you are not authorized to use or disclose this information, and we request that you notify us by reply mail or telephone and delete the original message from your mail system.
