Re: OPCODE tables
Ian, Hercules is IMHO rather lax. So often opcodes which were not enabled at a particular hardware level on physical hardware, but don't clash with any existing opcodes, may be enabled at on Hercules. Dave > -Original Message- > From: IBM Mainframe Assembler List > On Behalf Of Ian Worthington > Sent: Wednesday, March 20, 2024 11:37 PM > To: ASSEMBLER-LIST@LISTSERV.UGA.EDU > Subject: Re: OPCODE tables > > I have a dim and distant memory that the Hercules folks might be on top of > this > as, iirc, isn't is possible to change hardware level with a configuration > parameter? > > Best wishes / Mejores deseos / Best wishes > > Ian ... > > On Wednesday, March 20, 2024 at 10:12:03 PM GMT+1, Mark Hammack > wrote: > > Is there a list somewhere (other than OPTABLE LIST) that shows which > instructions were added at each hardware level? > > I thought PoP used to have something similar but I don't see anything back to > Revision 7 (oldest copy I have). > > > *Mark Hammack* >
Re: Is True Skip-Sequential Processing Possible with RECFM=FB,DSORG=PS?
> -Original Message- > From: IBM Mainframe Assembler List > On Behalf Of David S. > Sent: Saturday, November 11, 2023 1:59 PM > To: ASSEMBLER-LIST@LISTSERV.UGA.EDU > Subject: Is True Skip-Sequential Processing Possible with RECFM=FB,DSORG=PS? > > To help resolve a question posted to a LinkedIn group I manage: > www.linkedin.com/feed/update/urn:li:groupPost:910927- > 7128598004344786944 > ... I'd like to find out if there's any way to achieve *true* Skip-Sequential > processing with a Fixed Block Sequential File with a fairly short record > length (i.e. > DCB=(DSORG=PS,RECFM=FB,LRECL=80)? You don't say what the block size is. You don't say what the access methos is QSAM/BSAM > For example: Begin sequential processing at record number 100, *without* > having to read the first 99 records. Probably not. The data transfer is driven/implemented by a "channel program" and from what I remember a channel program can only read "blocks" from a disk, not parts of a block. So if the block size is 8000 bytes each read reads 100 80 byte records. The POINT MACRO does allow positioning. However this is a more complex question. Whilst with an "OS" type operating system allows an arbitrary physical record size to be defined for a dataset, on any current disk type, this is achieved by mapping this onto fixed size blocks which are what is actually written to the disk. So reading an 8k block will generally involve reading multiple blocks from the disk media > Note: We already know certain VSAM formats can do this, but the file in > question is a DSORG=PS *Sequential* file, *not* VSAM. Well again VSAM only reads BLOCKS so if we are talking large block sizes, you can only position to the block containing the record you want. > This is a rock-solid > requirement and cannot be changed. We also already know how certain utilities > such as SORT and REXX can *mimic* skip-sequential functionality by > *discarding* unwanted records until the specified record number is reached. > This is a likewise rock-solid requirement. Sequential processing > *must* begin at specified starting point and there can be *no* reading of any > records prior to that point. > My gut feeling is it *cannot* be done - at least not with RECFM=FB. It > *might* be possible with RECFM=F, but efficiency would then be so > compromised it would probably outweigh any advantage from *true* skip- > sequential processing. Like I say POINT can do this but you are then limited to BSAM... ... YOU DIDN'T SAY QSAM ONLY NOT VSAM Dave
Re: Tutorials for z and HLASM?
Folks, MVS 3.8J does not have HLASM only the old Assembler XF, and of course you can add other assemblers, but they are all old style, not HLASM compatible. The nearest thing to HLASM that's in the public domain is the Z390 package which contains everything you need to learn basic assembler on a PC, https://z390development.github.io/z390/ so Assembler, Macros, emulation of hardware and parts of MVS/zOS Dave > -Original Message- > From: IBM Mainframe Assembler List > On Behalf Of Michael Oujesky > Sent: Friday, October 6, 2023 4:00 PM > To: ASSEMBLER-LIST@LISTSERV.UGA.EDU > Subject: Re: Tutorials for z and HLASM? > > MVS 3.8 on Hercules might be an inexpensive alternative for the basics??? > > Michael > > > > >'course, the student needs to have access to z/OS :-) > > > >Mike Shaw > >MVS/QuickRef Support Group > >Chicago-Soft, Ltd.
Re: Will z/OS be obsolete in 5 years?
> -Original Message- > From: IBM Mainframe Assembler List > On Behalf Of Jon Perryman > Sent: Monday, August 7, 2023 11:05 PM > To: ASSEMBLER-LIST@LISTSERV.UGA.EDU > Subject: Re: Will z/OS be obsolete in 5 years? > > > On Thu, 20 Jul 2023 at 09:01, Rob van der Heij wrote: > > It would be interesting to see your evidence of IBM Z not performing well > > with > Linux. > > Linux on z performs better than Linux on most other hardware. My point is that > Linux wastes much of z hardware. > > Since I haven't seen Linux on z, I have to make some assumptions. It's > probably > fair to say the Linux filesystem still uses block allocation. Let's say it's > a 10 disk > filesystem and 100 people are writing 1 block repeatedly at the same time. > After > each writes 10 blocks, where are the 10 blocks for a specific user. > > In z/OS you > know exactly where those blocks would be in the file. If you read that file > are > these blocks located sequentially. While the filesystem can make a few > decisions, it's nothing close to the planning provided by SMS, HSM, SRM and > other z/OS tools. Yes but do you really? If you allocate a fixed file size you are wasting the un-used space at the end of the file, or if you run out of space its going elsewhere. I would argue that Linux is better at using disk capacity as you only ever waste half a block. Yes they might be scattered but how much data is on spinning disk and how much on SSD? > Like MS Windows disks, Linux filesystems can benefit from > defrag. Also consider when Linux needs more CPUs than available. Clustering > must be implemented on Linux to increase the number of CPU which does not > share the filesystem. In z/OS, a second box has full access to all files > because of > Sysplex. > If the data is in a SAN multiple systems can access them without a SYSPLEX... > I'm sure IBM has made improvements but some design limitations will be > difficult to resolve without the correct tools. For instance, can DB2 for > Linux on > z share a database across multiple z frames. It's been a while since I last > looked > but DB2 for z/OS was used because it outperformed DB2 for Linux on z. Why use DB2? Dave
Re: Will z/OS be obsolete in 5 years?
> -Original Message- > From: IBM Mainframe Assembler List > On Behalf Of Jon Perryman > Sent: Wednesday, July 19, 2023 1:47 AM > To: ASSEMBLER-LIST@LISTSERV.UGA.EDU > Subject: Will z/OS be obsolete in 5 years? > > IBM RHEL announced it's move to closed source (IBM RedHat Enterprise Linux). > With some changes, DB2, RACF and other z/OS products could run in Linux on > z16 in one sysplexed Linux image. A heck of a lot of changes, for a start z/OS is EBCDIC and Linux is some modern descendant of ASCII ... ... and if they ran on Linux on Z than why won't they run on Linux on some other platform, surely only the largest players need Z.. .. although Amazon, E-Bay, Microsoft Cloud Services seem to manage without it > We know it's possible because IBM moved > Unix and TCP into z/OS. Did they really "move" TCP/IP & UNIX? The original TCP/IP in MVS came from VM and was written in PASCAL so not UNIX based. >From what I remember USS was written from scratch. The entry in Wikipedia >seems to confirm this, it says :- https://en.wikipedia.org/wiki/UNIX_System_Services " ... It is the first UNIX 95 to not be derived from the AT source code. " So freshly created, not moved > IBM RHEL said closed source would force non-paying > customers to buy RHEL licenses but this makes no sense. As a statement, it makes perfect sense. If all else is equal it means they will receive money for something they don't at present. > Something else must be in play. Ah, a conspiracy theory. Of course other things are in play, but I believe they are more about protecting the image that "z" is different, in a good way to other platforms than moving zOS to Linux. In fact moving components from z/OS into Linux would, I believe devalue them and reduce their USPs > I created a survey at https://forms.gle/ZTPXsDJo8Z4H93sv7 to gain insights > into > IBM's decision to close source RHEL. You can skip the survey if you don't > want to > take it and view the survey results through this website. Feel free to pass > this > along. > I think IBM wants to integrate z/OS products to retain their investments and > expand their customer base.. Why do that. It would result in a huge loss of hardware revenue. IFLs for running UNIX are much cheaper than the CPUs needed to run z/OS. > Why is the z/OS community ignoring IBM RHEL closed source? Because its not relevant.? Is it ignoring it? > Are software vendors preparing their products for Linux? I assume that those that are relevant already have, but for any that were using free RHEL on Z to develop will now face extra charges. Will their prices go up? Will they exit the Z market. ... one last point, my question would be, is this likely to back-fire on IBM? Will it deter any one in a University or Academia from buying Z if they have to pay, or will IBM offer them a discount of 100%? Dave
Re: Notepad++ language formatting
> -Original Message- > From: IBM Mainframe Assembler List > On Behalf Of Paul Gilmartin > Sent: Saturday, June 3, 2023 10:27 PM > To: ASSEMBLER-LIST@LISTSERV.UGA.EDU > Subject: Re: Notepad++ language formatting > > On 6/3/23 12:29:30, Abe Kornelis wrote: > > > > based on the work by Charles Mills I created an updated/extended > > version including all current instructions according PoP, more macros, > > more register names, and more file types. > > > > It is not perfect, but it does a reasonable job. > > > > So I submitted it to the Notepad++ community. > > They've taken it up in their library/repository at > > https://github.com/notepad-plus-plus/userDefinedLanguages > > > > If you want to give it a try, you can import the definitions from that > > repository. Thank you Abe. I may give that a try... .. not my original post but I will go ++1 for notepad++ > > Why Notepad++? I'd expect Kedit or The to be more familiar to the HLASM > community? > Possibly but I could really never get used to THE on windows. I always recommend it, and I sometimes use it for those who yearn for a Mainframe, but its not my go-to editor for windows/linux files. .. it lacks many features I feel are indispensable on Windows, so THE has no tabbed windows, no support for different character sets or windows/linux line endings, > Better macro support? In what language are macros coded? > Portability? Is Notepad++ available on desktop platforms other than one, or > are > the macros editor-agnostic? Of course, there's WINE, VirtualBox, or VMWare. > Which of those would require a license fee? KEDIT needs a licence, is $39/machine. I have four machines. It also has only "legacy" support. Notepad++ comes with parsers for many of the languages I write in. For me it’s a no-brainer. Its often updated for new formats. There is an active support forum. So if you wish to stick with THE/KEDIT thats fine but for those of us who have changed, that should also be fine. > > -- > gil Dave
Re: HLASM code page support enhancements
> -Original Message- > From: IBM Mainframe Assembler List > On Behalf Of Ze'ev Atlas > Sent: 13 February 2023 18:10 > To: ASSEMBLER-LIST@LISTSERV.UGA.EDU > Subject: Re: HLASM code page support enhancements > > The real question is why, but really why, IBM had to introduce this EBCDIC > horror, where symbols like [,], ^ and some less signifacant ones moved around > like dry leaves in the fall wind. I believe that the real answer is that IBM didn't introduce these characters, "users", I think mainly universities found they needed them and so tweaked their systems so they could be used. Its also apposite to remember that "about" this time IBM thought it was possible it was going to be split into two parts so the mid range products were produced with slightly standards. There were many other idiosyncrasies around this time. So there was a concept of primary and secondary currency symbols. On a system running the "UK Language" (that is English English) the primary currency symbol is £(pound) and the secondary $(dollar) On a system running American English the primary currency symbol is $(dollar) and the secondary ¢(cent). This meant documents sent from the UK to the USA containing currency symbols > Why didn't IBM jist left them in one place. It did. IBM only has one place for them > I did > never find any explanation, let alone logical explanation. As a maintainer of > regular expression engine (PCRE) on EBCDIC, I have to deal with the horrible > results of that stuff on regular basis. I had to resort to use iconv() not > between > EBCDIC and ASCII, but even within th EBCDIC world. My users have to convert > the regex and target strings to some equal base (usually 1047) and back. > Instead of taking responsibility, IBM just introduced new code pages that > increased confusion rather than solving the issue. > I am disapointed Once the genie is out of the bottle its reluctant to return. > ZA > When I supported some software designed to connect IBM systems to X.25 networks, which are generally "ASCII" this was always good as a distraction. Some sites wanted one option, others a different one. And if you are supporting file transfer to DEC machines you had better get it right as many DEC operating system use "[" and "]" to delimit directories in file names. Dave
Re: When did logical instructions appear?
> -Original Message- > From: IBM Mainframe Assembler List > On Behalf Of Robin Vowels > Sent: 17 June 2022 09:39 > To: ASSEMBLER-LIST@LISTSERV.UGA.EDU > Subject: Re: When did logical instructions appear? > > On 2022-06-17 18:20, Seymour J Metz wrote: > > IBM was sign-magnitude in the 1950s, but CDC and UNIVAC inherited 1s' > > complement from ERA. I'm not sure what the first 2's complement > > machine was. > > EDSAC was working in 1949. > > It may not have been the first. > Manchester Baby in 1948 was also 2's complement. So the first program from RAM used 2's complement. Dave
Re: When did logical instructions appear?
Seymour, (Hope that's ok) Many early machines were serial. The Manchester SSEM and it successors the Manchester MK1 and Ferrante MK1* were all serial, as was the Ferranti Pegasus. The machine at Cambridge(UK), EDSAC was also serial. Not sure about ENIAC but wasn't that a decimal machine as well?. EDVAC was also serial. For example, the Manchester Baby was a 32 bit machine with three Williams tubes, Main Store (32 x 32) Accumulator (1 x 32) Control Store (2 x 32) To build that as a parallel machine would have needed 96 Williams tubes, I believe that even the IBM 701 only had 72. .. so I think if you are building a machine with storage that is inherently serial at some level, so Williams Tubes, Delay Lines or even a drum it makes sense to build a serial machine. Once you start using core storage and transistors the mathematics change and parallel becomes much more attractive... Dave > -Original Message- > From: IBM Mainframe Assembler List > On Behalf Of Seymour J Metz > Sent: 17 June 2022 09:05 > To: ASSEMBLER-LIST@LISTSERV.UGA.EDU > Subject: Re: When did logical instructions appear? > > FSVO serial. The early electronic machines that I'm aware of were parallel. > > FWIW, there were papers claiming that 1s' complement was simpler. I believe > that the tradeoffs vary depending on the technology used. > > > -- > Shmuel (Seymour J.) Metz > http://mason.gmu.edu/~smetz3 > > > From: IBM Mainframe Assembler List [ASSEMBLER-LIST@LISTSERV.UGA.EDU] > on behalf of Robin Vowels [robi...@dodo.com.au] > Sent: Friday, June 17, 2022 2:40 AM > To: ASSEMBLER-LIST@LISTSERV.UGA.EDU > Subject: Re: When did logical instructions appear? > > - Original Message - > From: "Paul Gilmartin" <0014e0e4a59b-dmarc- > requ...@listserv.uga.edu> > To: > Sent: Friday, June 17, 2022 7:20 AM > Subject: Re: When did logical instructions appear? > > > > On Jun 16, 2022, at 10:43:36, Robin Vowels wrote: > >> > >> Computers have had instructions for signed and unsigned binary since > >> at least 1951. When negative values are expressed using twos > >> complement notation, ordinary addition will give the same result > >> whether the operation is signed or unsigned. > >> > > It puzzles me that some of the oldest computers employed sign- > > magnitude notation when 2's (1's, 10's) complement would have needed > > fewer gates and fewer clock cycles. > > For a serial machine (and most of them were in the early days), twos > complement was the simplest. It needed only one cycle for add and subtract. > Even subtract (complement and add one) was done in a single cycle, "on the fly". > It was unnecessary to add the one; complement commencing after the first non- > zero bit. > > Ones complement was a PITA, because a carry out of the high end required a 1 > to be added in the next cycle. This was no good at all for array machines such as > Pilot ACE, DEUCE, and ACE, because the word just summed would not have been > around to add the final "1" produced by the carry out -- the arithmetic unit > already working on summing (or subtracting) the next pair of words. > > > Perhaps an accommodation to the engineers' habits. > > --- > This email has been checked for viruses by Avast antivirus software. > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.av > ast.com%2Fantivirusdata=05%7C01%7Csmetz3%40gmu.edu%7Cf84bb17 > cd7eb400175a608da502c27ae%7C9e857255df574c47a0c00546460380cb%7C0 > %7C0%7C637910447840045536%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4 > wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C > %7C%7Csdata=o2r1kMl7%2F4ORpMDX%2Br1beF%2F271qN32kc3tBcqz6 > H7l0%3Dreserved=0
Re: Storage-Key-Removal Facility
> -Original Message- > From: IBM Mainframe Assembler List l...@listserv.uga.edu> On Behalf Of Bob Raicer > Sent: 07 June 2022 01:13 > To: ASSEMBLER-LIST@LISTSERV.UGA.EDU > Subject: Storage-Key-Removal Facility > > While browsing the SA22-7832-13 version of Principles of Operation I saw this > text on Page 1-28: > > |Storage-Key-Removal Facility > | > |The storage-key-removal facility may be available on a model > |implementing z/Architecture. A configuration with the > |storage-key-removal facility installed does not have the ability to use > |any key protection mechanisms. Setting or reading of a storage key is > |prohibited and the PSW key and any specified key must be zero otherwise > |an exception condition is recognized. > > Can any of you provide some insight regarding the motivation for the > introduction of this facility, and perhaps what operating system might exploit > it? Perhaps its to stop you running some products.. ... and CPUs with this feature might be cheaper > > Thanks. > > Bob Dave G4UGM
Re: Does HLASM use NOTE and POINT on UNIX files?
> -Original Message- > From: IBM Mainframe Assembler List l...@listserv.uga.edu> On Behalf Of Schmitt, Michael > Sent: 31 March 2022 17:58 > To: ASSEMBLER-LIST@LISTSERV.UGA.EDU > Subject: Re: Does HLASM use NOTE and POINT on UNIX files? > > Good point. Maybe it was a System/36? I would have thought a System/38. Really the predecessor of the AS/400. Even System/36 was not available in 1980 Dave > > -Original Message- > From: IBM Mainframe Assembler List l...@listserv.uga.edu> On Behalf Of Dave Clark > Sent: Thursday, March 31, 2022 11:53 AM > To: ASSEMBLER-LIST@LISTSERV.UGA.EDU > Subject: Re: Does HLASM use NOTE and POINT on UNIX files? > > "IBM Mainframe Assembler List" > wrote on > 03/31/2022 12:47:06 PM: > > In 1980 I worked at a photofinishing plant that used punched cards > > with an IBM minicomputer running AS/400. It also used paper tape, but > > not with the AS/400. > > > > Can anyone guess why? I'll give a hint: it is industry workflow related. > > > I don't have the answer to your question, but -- color me confused > -- how did you work on an AS/400 in 1980 when it didn't become available > until 1988? > > > Sincerely, > > Dave Clark > -- > int.ext: 91078 > direct: (937) 531-6378 > home: (937) 751-3300 > > Winsupply Group Services > 3110 Kettering Boulevard > Dayton, Ohio 45439 USA > (937) 294-5331 > > > > > > ** > *** > This email message and any attachments is for use only by the named > addressee(s) and may contain confidential, privileged and/or proprietary > information. If you have received this message in error, please immediately > notify the sender and delete and destroy the message and all copies. All > unauthorized direct or indirect use or disclosure of this message is strictly > prohibited. No right to confidentiality or privilege is waived or lost by any > error in transmission. > ** > ***
Re: S/360 emulation in PC/370
> -Original Message- > From: IBM Mainframe Assembler List l...@listserv.uga.edu> On Behalf Of Seymour J Metz > Sent: 20 December 2020 17:12 > To: ASSEMBLER-LIST@LISTSERV.UGA.EDU > Subject: Re: S/360 emulation in PC/370 > > The 360/30, 360/40 and 360/50 had integrated channels, cycle stealing from > the CPU microcode. The channel-control unit-device structure was very > similar to that of the 7000 series and the 7030. When the S/360 came out, > channel I/O was the norm, and Interrupts go back to the 1950s. > But its quite alien to those of a certain age brought up on 8 and 16-bit Microprocessors. The 6502 and 6800/09 only have memory IO. The 8080 and other family chips do have a separate IO space, but it uses the same data bus. Essentially its memory mapped IO. The fact that on S/360 a single IO can store information in multiple disparate locations. Things like the serial lines where you can see data arriving > Small machines like the 650 and 1401 had simpler I/O, but I don't recall > anything older than the PDP-11 that had memory-mapped I/O. > The Ferranti Pegasus I, a valve/tube computer dating from 1956 had memory mapped IO https://en.wikipedia.org/wiki/Ferranti_Pegasus there were two memory locations for input, and two for output. This allows "normal" binary IO where you send the binary value of the character, and numeric IO where the bottom 4 bits are interpreted as an integer and the corresponding characters 0-9 output or input The numeric output was necessary as they used a an odd character set for the teleprinters, not IA2. > > -- > Shmuel (Seymour J.) Metz > http://mason.gmu.edu/~smetz3 > Dave G4UGM
Re: Hercules-I've forgotten the manual for IFOX00 macro reference
IFOX is actually XF. The Assembler F (and E) manual is here http://www.bitsavers.org/pdf/ibm/360/asm/C28-6514-5_IBM_System_360_Assembler_Language_Level_E_F_Dec67.pdf the manual I think you want is the OS/VS DOS and VM Assembler Manual which is for IFOX00. There are a couple of versions here http://www.bitsavers.org/pdf/ibm/370/OS_VS/assembler/ plus some other guide. Dave G4UGM > -Original Message- > From: IBM Mainframe Assembler List l...@listserv.uga.edu> On Behalf Of Rupert Reynolds > Sent: 31 October 2020 13:27 > To: ASSEMBLER-LIST@LISTSERV.UGA.EDU > Subject: Hercules-I've forgotten the manual for IFOX00 macro reference > > Title says it all. I'm writing macros for MVS 3.8J on TK4- Hercules, using > Assembler F, but some of the conditional assembly is gone from my memory. > > Does anyone have the manual ID to search for, or even a download link, > please? > > Thanks in advance. > > Rupert
