Radoslaw Skorupka got some good answers to his questions, but I can fill
in some gaps:
2. While z/TPF can certainly run as a z/VM guest, that's at least not
common for production instances.
3.1. There's a base z/TPF license plus some popular options such as the
z/TPF High Performance Option
A 64 bit (or longer) binary counter?
> -Original Message-
> From: IBM Mainframe Discussion List On
> Behalf Of Timothy Sipples
> Sent: Sunday, March 21, 2021 8:44 PM
> To: IBM-MAIN@LISTSERV.UA.EDU
> Subject: Re: Contents of TOD Programmable Field under z/OS?
>
> It's possible for a
It's possible for a random number generator to produce duplicate output.
Statistically speaking, a duplicate (random number collision) is
guaranteed if you keep generating random numbers and merely wait long
enough. If you combine a time of day number (which is generally assumed
monotonically
Implementing overlapped I/O is what QSAM does. You don't even need to code
BUFNO. IMHO it is one of the two main points of QSAM, the other being
blocking and de-blocking.
I agree on GET LOCATE. PUT LOCATE on the other hand is a PITA (IMHO, of
course).
Charles
-Original Message-
From:
So implementing asynchronous I/O in QSAM is as simple as having BUFNO= the
right number
thanks
-Original Message-
From: IBM Mainframe Discussion List On Behalf Of
Michael Stein
Sent: Sunday, March 21, 2021 5:41 PM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: Overlapped I/O completion
On Sun, Mar 21, 2021 at 04:54:45PM -0400, Joseph Reichman wrote:
> Just to make sure I am understanding correctly I use GETPOOL/GETBUFF
> with QSAM it will use Asynchronous/overlapped i/o right ?
You should only need DCB/OPEN/CLOSE/GET.
Let most everything default, QSAM knows what to do for
The rules is *sometimes* true. But not always.
Few examples:
Tapes: 726, 727, 728, 729, 7330 ...24xx family, 34xx family, 3480, 3490
---> 3590, 3592.
CPC: 9671, 20xx, 390x, 856x
Libraries: 3995, 3994, 3584, 3995...
Disk: 5444, 1405
and 7302 - not a disk...
2301 is a drum - DASD, but not disk
If youre using GETPOOL/GETBUF then youre not doing QSAM. GETBUF is for
BSAM. You would be OPENING the file then using READ macros to read in
your records.
If youre doing QSAM, then you just issue the OPEN followed by a GET.
There is no READ. The system takes care of the READs and buffers.
Joe
MXG Support for TPF:
Change 17.200 Support for IBM's TPF Operating System.
EXTPFxxForty datasets are created from the fifty or so records.
FORMATSSome datasets are written at monitor initialization to
IMACTPFmap things, but the interval records are deaccumulated
x2yz would be a terminal type device (e.g. 2260, 3270)
x3yz would be a disk type device (e.g. 2301, 2311, 2314, 3330, 3390)
x4yz would be a tape type device (e.g. 2400)
x5yz would be a card type device (e.g. 2540)
x7yz would be telecommunications type device (e.g. 2701, 2780, 3780)
In all cases
> STCKF is better for cases where you do not need that uniqueness
Can't emphasize that enough. If you are using STCK and all you need is "the
time," not "a time that is not identical to any other possible STCK" then
you are wasting LOTS of CPU cycles -- use STCKF instead.
In fact, I guess you
Joe
Just to make sure I am understanding correctly I use GETPOOL/GETBUFF with QSAM
it will use Asynchronous/overlapped i/o right ?
-Original Message-
From: IBM Mainframe Discussion List On Behalf Of Joe
Monk
Sent: Sunday, March 21, 2021 1:24 PM
To: IBM-MAIN@LISTSERV.UA.EDU
Thanks. Had to change the unprintable's but it works fine.
On Sat, 20 Mar 2021 19:35:49 -0400 Tony Thigpen wrote:
:>There is not a 'standard' search tool in VM. There are numinous versions
:>that are available for the asking. Just post a request on the VM list.
:>Almost all of them are just a
Well, I downloaded and tried FERRET and it never found anything.
Unfortunately it is compiled so I could not figure out what was wrong.
Tried a single minidisk as well as multiple disks. Tried CAPS, tried lower
case, etc.
On Sat, 20 Mar 2021 23:05:11 -0400 Phil Smith III wrote:
:>I just found
> The 3215 was the s/360 console printer keyboard
No; the 1052-7 was the console typewriter for various S/360 models. The 3210
and 3215 were console typewriters for low end S/370 models, eventually replaced
by special models of the 3270, e.g., 3278-2A, 3279-2C.
--
Shmuel (Seymour J.) Metz
You're right -- probably 2311 (DASD)
3211, however, was a printer.
On 2021-03-21 15:08, Radoslaw Skorupka wrote:
W dniu 20.03.2021 o 09:47, Attila Fogarasi pisze:
Programs on ACP were limited to 4k size originally, and files were
limited
to 2 record sizes (short and long), the sizes being
Xerox produced a 3211 cartridge disk system.
Sent from Yahoo Mail for iPhone
On Sunday, March 21, 2021, 3:09 PM, Radoslaw Skorupka
wrote:
W dniu 20.03.2021 o 09:47, Attila Fogarasi pisze:
> Programs on ACP were limited to 4k size originally, and files were limited
> to 2 record sizes (short
"3211" was presumably a typo for 2311, since the 3211 is an impact printer,
substantially faster than the 1403 and with a forms control buffer (FCB)
instead of a carriage tape.
--
Shmuel (Seymour J.) Metz
http://mason.gmu.edu/~smetz3
From: IBM
atry this on a Windows Intel box . http://www.z390.org/
On Tue, Mar 16, 2021 at 11:55 AM Support, DUNNIT SYSTEMS LTD. <
supp...@dunnitsys.com> wrote:
> Hi all,
>
> I was approached by a university student who wants self study z/OS
> architecture and Assembler - including 64 bit programming - as
> Unless you are reading multple files (multiple DCBs) at once (each
>with their own group of pending READs) issuing WAIT before
> CHECK is just wasted effort/CPU time.
No. You may have CPU intensive work you can do.
--
Shmuel (Seymour J.) Metz
http://mason.gmu.edu/~smetz3
W dniu 20.03.2021 o 09:47, Attila Fogarasi pisze:
Programs on ACP were limited to 4k size originally, and files were limited
to 2 record sizes (short and long), the sizes being optimized for 3211 disk
geometry. Those limitations were removed 40 years ago :) However the
speed of zTPF comes from
Basic EOV is transparent, but if you have the "unlike attributes" bit set,
things happen that you must be aware of.
--
Shmuel (Seymour J.) Metz
http://mason.gmu.edu/~smetz3
From: IBM Mainframe Discussion List [IBM-MAIN@LISTSERV.UA.EDU] on behalf of
SuperC is also included in ISPF. Of course, ISPF is not ubiquitous in the VM
world the way that it is in the MVS world; if you don't have it, it's a lot
less expensive to go the HLASM Toolkit route.
--
Shmuel (Seymour J.) Metz
http://mason.gmu.edu/~smetz3
On Sun, 21 Mar 2021 10:08:13 -0500, Joel C. Ewing wrote:
>Believe it.
>
Performance is unsatisfactory.
I must do something.
BSAM is something.
Therefore I must do BSAM.
-- gil
--
For IBM-MAIN subscribe / signoff / archive
"The queued access technique provides GET and PUT macro instructions for
transmitting data within virtual storage. These macro instructions cause
automatic blocking and deblocking of the records stored and retrieved.
Anticipatory (look-ahead) buffering and synchronization (overlap) of input
and
> When I do a qsam get the physical I/O is for 1 block every get just ups a
> pointer
No. When you do a GET, QSAM not only returns a logical record, it also does
whatever housekeeping is necessary. That includes scheduling the I/O for
subsequent blocks if necessary. Further, the number of CCWs
For GET it's BUFNO, for READ it's NCP.
--
Shmuel (Seymour J.) Metz
http://mason.gmu.edu/~smetz3
From: IBM Mainframe Discussion List [IBM-MAIN@LISTSERV.UA.EDU] on behalf of
Joseph Reichman [reichman...@gmail.com]
Sent: Sunday, March 21, 2021 11:08 AM
To:
OPTCD=C chained scheduling goes all the way back to OS/360, and was not limited
to DASD. Starting with SAM-E, a more efficient type of chained scheduling was
automatic for DASD. BSAM and QSAM chain new requests to the current channel
program and reschedule them if channel program terminates too
The code will be hard to maintain. It would be more maintainable to write a
well commented subroutine in assembler. If you don't have the staff to
understand and update that, then you also don't have the staff to understand
the embedded machine code.
--
Shmuel (Seymour J.) Metz
On 2021-03-21, at 07:52:27, Peter Relson wrote:
>
> The software will not have to do anything in order to get the epoch index
> to increase to 1 in September 2042. ...
>
Thanks. I saw that cleearly in the PoOps.
> The clock comparator remains an 8 byte entity. But the OS will be able to
>
Linux and Unix happily coexist in mainframes. Big chunks of z/OS use Unix
System Services, there's lots of Linux use in IFL and z/VM, and it is common to
have Linux communicating with z/OS.
--
Shmuel (Seymour J.) Metz
http://mason.gmu.edu/~smetz3
From:
Binyamin,
Not a command, but a full screen utility. Check out my FERRET package at
http://www.vm.ibm.com/download/packages/descript.cgi?FERRET
--
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to
On 3/21/2021 7:21 AM, Joseph Reichman wrote:
I don’t understand what the statement “QSAM does overlapped I/O automatically”
When I do a qsam get the physical I/O is for 1 block every get just ups a
pointer
QSAM does overlapped I/O (and has done for many, Many, MANY years).
If you want to
Yes. Default varies by type of device.
Sent from my iPhone
> On Mar 21, 2021, at 11:08 AM, Joel C. Ewing wrote:
>
> Believe it.
>
> Even before emulated DASD, MVS QSAM would read multiple blocks with a
> single channel program to eliminate rotational delays on native DASD and
> do
Believe it.
Even before emulated DASD, MVS QSAM would read multiple blocks with a
single channel program to eliminate rotational delays on native DASD and
do anticipatory reads for the next set of buffers even while you were
still processing records in blocks from the previous read, as long as
Thank you does the number “GET” ahead I/o depend on Buffno
> On Mar 20, 2021, at 11:31 AM, Michael Stein wrote:
>
> On Fri, Mar 19, 2021 at 03:35:39PM -0400, Joseph Reichman wrote:
>> So this is what I will do
>>
>> I’ll do 3 reads in the first since i need to get myself going I’ll issue
From Jim Mulder:
Jim Mulder
2/4/17
to
There are no coding requirements for the application, When you do
a QSAM OPEN for Input, the first read-ahead I/Os are scheduled by OPEN,
and the application program can proceed without waiting after the OPEN at
least to the point of doing the first
I don’t understand what the statement “QSAM does overlapped I/O automatically”
When I do a qsam get the physical I/O is for 1 block every get just ups a
pointer
BSAM allows me to do multiple Reads each with their own DECB
So I already initiate lots of physical I/O mainly because I have lots
The software will not have to do anything in order to get the epoch index
to increase to 1 in September 2042. It will happen when the clock wraps,
as long as you're running on a machine that supports the multiple epoch
facility (maybe the OS has to enable something, but that would be about
The STCKE result, like the STCK result, is architecturally guaranteed to
be unique across all the CPUs used by an operating system image (i.e.,
within an LPAR). This is not a sysplex statement; sysplex is not an
architectural construct. The STCKF result, on the other hand, is not
guaranteed
Charles,
I know Tom Brennan's Vista. I even got one from him. For free. (I didn't
ask for it! It was a part of longer story, related to polish codepage).
And I have no doubt he knows there are both 3270 and 5250.
However lurking or peeking is not the best method, especially you
sometimes see
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