Read only coding does not require heavy lifting, although it is a bit more complicated. Reentrant coding requires an understanding of serialization, and is best learned after mastery of the basics.
If I were teaching an HLASM course I would use "black box" prolog and epilog macros at firsdt, and later teach about dynamic storage allocation and chaining of save areas. And, yes, I would start with jumps (relative branches) and only cover the RS branches later. -- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Assembler List [[email protected]] on behalf of Ed Jaffe [[email protected]] Sent: Saturday, September 17, 2022 11:29 AM To: [email protected] Subject: Re: Assembler courses On 9/17/2022 2:06 AM, Abe Kornelis wrote: > Starting with reentrant programming seems a pretty tough call. Not sure why re-entrant programming should be considered heavy lifting. Would not any assembler course teach about USING? A typical non-reentrant program has a single code/data segment and a single USING. A typical reentrant program has two segments: one for code and one for data -- each with its own USING. This has been common practice on other platforms (e.g., Intel) for decades. If I were to teach an HLASM course, I can envisage my very first recommended program organization diagram showing both a code and a data segment and never once suggesting at any time during the class that code and data can be (or ever historically were) mixed. Example: | R12 -> .---------. R13 -> .---------. | | | | | | | Code | | Data | | | Segment | | Segment | | | | | | | '---------' '---------' > Baseless should - I guess - pose less of a challenge. Agreed. I would not make mention of based branches until the more advanced portions of the class. -- Phoenix Software International Edward E. Jaffe 831 Parkview Drive North El Segundo, CA 90245 https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.phoenixsoftware.com%2F&data=05%7C01%7Csmetz3%40gmu.edu%7C6636c9bb1b554785ec5408da98c160a8%7C9e857255df574c47a0c00546460380cb%7C0%7C0%7C637990253587277381%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=AhG7BWwUUE%2BJ2EZYWWHsDrVKGWbMxlA%2Bp2D7lh%2BufF8%3D&reserved=0 -------------------------------------------------------------------------------- This e-mail message, including any attachments, appended messages and the information contained therein, is for the sole use of the intended recipient(s). If you are not an intended recipient or have otherwise received this email message in error, any use, dissemination, distribution, review, storage or copying of this e-mail message and the information contained therein is strictly prohibited. If you are not an intended recipient, please contact the sender by reply e-mail and destroy all copies of this email message and do not otherwise utilize or retain this email message or any or all of the information contained therein. Although this email message and any attachments or appended messages are believed to be free of any virus or other defect that might affect any computer system into which it is received and opened, it is the responsibility of the recipient to ensure that it is virus free and no responsibility is accepted by the sender for any loss or damage arising in any way from its opening or use.
