Any discontinued S/360 appl. instructions? 
Author Message
 Any discontinued S/360 appl. instructions?

Have any application program (not supv. state) instructions from early
S/360 been discontinued on today's machines, on either MVS or VSE?


Tue, 11 Feb 2003 10:46:09 GMT  
 Any discontinued S/360 appl. instructions?
I can't think of any, though some instructions have effectively been
replaced by others.

For example --

TS (CS, CSD)

MVO (SRP)

In addition, precise definitions have changed.  TS comes to mind, as
well as the floating point instructions.

IBM can't really drop problem state instructions, for the simple reason
some programs actually use them.  IBM basically guarantees an existing,
working program will continue to work.  See Principles of Operation.

-- Steve Myers


Quote:
>Have any application program (not supv. state) instructions from early
>S/360 been discontinued on today's machines, on either MVS or VSE?



Tue, 11 Feb 2003 03:00:00 GMT  
 Any discontinued S/360 appl. instructions?

Quote:
>I can't think of any, though some instructions have effectively been
>replaced by others.

>For example --

>TS (CS, CSD)

>MVO (SRP)

>In addition, precise definitions have changed.  TS comes to mind, as
>well as the floating point instructions.

>IBM can't really drop problem state instructions, for the simple reason
>some programs actually use them.  IBM basically guarantees an existing,
>working program will continue to work.  See Principles of Operation.

>-- Steve Myers


>>Have any application program (not supv. state) instructions from early
>>S/360 been discontinued on today's machines, on either MVS or VSE?

Well, yes, actually there have been a few instructions which have
been dropped, although I'm not sure if they count.  The ones I'm
thinking of were the Branch and Store (BAS/BASR) instructions
(Opcode 0D/4D) that were present on the S/360 (model 67 only?), but
had disappeared from the S/370 instruction set.  These were
resurrected as the Branch and Save (BAS/BASR) instructions (Opcodes
0D/4D) on the 370/XA machines.

There were also instructions like ISK and SSK (Insert Storage Key
and Set Storage Key) which were present on the S/360, but have
disappeared on the ESA/390 machines (having been replaced by the
ISKE and SSKE instructions).  But, since these are (semi-)
privileged, I'm not sure they count.

Plus, some of the S/360s supported the WRD and RDD (Write Direct and
Read Direct) instructions, which are no longer present in the ESA
machines.  My green card indicates that these were not privileged on
the S/360 (although that may be a typo, which, unfortunately I can't
verify since my S/360 Pops is in storage), although they were
privileged on the S/370.  What's interesting is that the opcodes for
these were reused in the ESA machines.

There were also the STMC and LMC (STore Multiple Control and Load
Multiple Control) instructions on the S/360 (model 67 only?), which
disappeared for the S/370, but, again, these are privileged.

Of course, all of the I/O instructions disappeared with the switch
to XA, but, since those are privileged, they don't count.

Somewhere, I have a chart of all of the instructions which existed
on the S/360-ESA/390 machines.  Note that there were LOTS of
instructions which never made the Pops, instead being documented in
various extensions manuals.  I'll see if I can dig the list up if
anyone is interested (And, it only lists documented instructions;
no undocumented/unannounced instructions are in it.).

Dave

P.S. Standard Disclaimer: I work for them, but I don't speak for them.



Tue, 11 Feb 2003 03:00:00 GMT  
 Any discontinued S/360 appl. instructions?

Quote:

>Plus, some of the S/360s supported the WRD and RDD (Write Direct and
>Read Direct) instructions, which are no longer present in the ESA
>machines.  My green card indicates that these were not privileged on
>the S/360 (although that may be a typo, which, unfortunately I can't
>verify since my S/360 Pops is in storage), although they were
>privileged on the S/370.  What's interesting is that the opcodes for
>these were reused in the ESA machines.

S/360 POps says that RDD and WRD were privileged.

- Jim Saum



Tue, 11 Feb 2003 03:00:00 GMT  
 Any discontinued S/360 appl. instructions?
<snip>
Quote:
> Well, yes, actually there have been a few instructions which have
> been dropped, although I'm not sure if they count.  The ones I'm
> thinking of were the Branch and Store (BAS/BASR) instructions
> (Opcode 0D/4D) that were present on the S/360 (model 67 only?), but
> had disappeared from the S/370 instruction set.  These were
> resurrected as the Branch and Save (BAS/BASR) instructions (Opcodes
> 0D/4D) on the 370/XA machines.

<snip>

The BAS/BASR were also on the S/360-20 & I think 25.  They "went
away" for a while, but came back with S/370-XA for 31 bit
addressing.

--
Steve Thompson
OSP LLC
330/335-9907 office
330/334-2097 fax

Remove "_" in email address to contact me -- anti-spam measures
in use



Tue, 11 Feb 2003 03:00:00 GMT  
 Any discontinued S/360 appl. instructions?

Quote:

<snip>

> Well, yes, actually there have been a few instructions which have
> been dropped, although I'm not sure if they count.  The ones I'm
> thinking of were the Branch and Store (BAS/BASR) instructions
> (Opcode 0D/4D) that were present on the S/360 (model 67 only?), but
> had disappeared from the S/370 instruction set.  These were
> resurrected as the Branch and Save (BAS/BASR) instructions (Opcodes
> 0D/4D) on the 370/XA machines.

Yes, I believe those were /67 only.  The replacements behave identically as far
as I can tell.  Another legacy from that fine architecture.

Quote:

> There were also instructions like ISK and SSK (Insert Storage Key
> and Set Storage Key) which were present on the S/360, but have
> disappeared on the ESA/390 machines (having been replaced by the
> ISKE and SSKE instructions).  But, since these are (semi-)
> privileged, I'm not sure they count.

ISK/SSK were privileged.

Quote:
> Plus, some of the S/360s supported the WRD and RDD (Write Direct and
> Read Direct) instructions, which are no longer present in the ESA
> machines.  My green card indicates that these were not privileged on
> the S/360 (although that may be a typo, which, unfortunately I can't
> verify since my S/360 Pops is in storage), although they were
> privileged on the S/370.  What's interesting is that the opcodes for
> these were reused in the ESA machines.

These are actually quite interesting.  WRD/RDD were privileged and a (object)
program that used them would be quite surprised on modern machines since the
opcodes are now X'85'=BRXLE and X'84'=BRXH!

Quote:
> There were also the STMC and LMC (STore Multiple Control and Load
> Multiple Control) instructions on the S/360 (model 67 only?), which
> disappeared for the S/370, but, again, these are privileged.

Again yes, /67 instructions.

Quote:

> Of course, all of the I/O instructions disappeared with the switch
> to XA, but, since those are privileged, they don't count.

> Somewhere, I have a chart of all of the instructions which existed
> on the S/360-ESA/390 machines.  Note that there were LOTS of
> instructions which never made the Pops, instead being documented in
> various extensions manuals.  I'll see if I can dig the list up if
> anyone is interested (And, it only lists documented instructions;
> no undocumented/unannounced instructions are in it.).

There still are.  CSP is only documented in an online addendum to the PoO, for
example.

Quote:

> Dave

> P.S. Standard Disclaimer: I work for them, but I don't speak for them.

Bob


Tue, 11 Feb 2003 03:00:00 GMT  
 Any discontinued S/360 appl. instructions?

(snip some replies to the question about dropped instructions.)
(and someone else wrote)

Quote:
>> Somewhere, I have a chart of all of the instructions which existed
>> on the S/360-ESA/390 machines.  Note that there were LOTS of
>> instructions which never made the Pops, instead being documented in
>> various extensions manuals.  I'll see if I can dig the list up if
>> anyone is interested (And, it only lists documented instructions;
>> no undocumented/unannounced instructions are in it.).
>There still are.  CSP is only documented in an online addendum to the PoO, for
>example.

I believe that CSP is supposed to appear in the next PoO.

But SIE, and the MVS assist instructions have their own manuals, and
don't seem to be making their way into PoO.

If some non-priveleged instructions did disappear they would have a
simulator for them.  (The 360/91 had a simulator for decimal instructions,
and there was IEAXPSIM for simulating extended precision.  Also, the
the original machines with extended precicion did not have DXR, so it
was always simulated.  

You could say that the 91 had lost the decimal instructions, though.

-- glen



Wed, 12 Feb 2003 08:38:48 GMT  
 Any discontinued S/360 appl. instructions?
The exact definition of the floating point instructions also changed
on the /91.

--Steve Myers


[snip]

Quote:
>You could say that the 91 had lost the decimal instructions, though.

>-- glen



Wed, 12 Feb 2003 10:54:56 GMT  
 Any discontinued S/360 appl. instructions?

Quote:
>The exact definition of the floating point instructions also changed
>on the /91.
>--Steve Myers

I forgot about that one.  Though I don't know how exactly they were
defined, but it did give different answers.  The /91 gave rounded
instead of truncated results for floating divide.  More accurate but
different.  

ESA/390 PoO does say:

  The fraction is then truncated to the proper result-fraction length.

I don't know if S/360 PoO says that, or not.

Though if you want to get into changes in floating point, note that
the guard digit on all floating point was added after the initial release
of S/360.  They retrofitted the change on existing machines!
So, that would be a change, from one version of S/360 to another, of
non-priveleged instructions.

-- glen



Fri, 14 Feb 2003 03:00:00 GMT  
 Any discontinued S/360 appl. instructions?
Yes, the Improved Floating Point Engineering change did alter floating
point results, and also required PTFs.  I am almost certain the S/360
POP explicitely states floating point results are truncated.

-- Steve Myers


Quote:

>>The exact definition of the floating point instructions also changed
>>on the /91.

>>--Steve Myers

>I forgot about that one.  Though I don't know how exactly they were
>defined, but it did give different answers.  The /91 gave rounded
>instead of truncated results for floating divide.  More accurate but
>different.  

>ESA/390 PoO does say:

>  The fraction is then truncated to the proper result-fraction length.

>I don't know if S/360 PoO says that, or not.

>Though if you want to get into changes in floating point, note that
>the guard digit on all floating point was added after the initial release
>of S/360.  They retrofitted the change on existing machines!
>So, that would be a change, from one version of S/360 to another, of
>non-priveleged instructions.

>-- glen



Fri, 14 Feb 2003 03:00:00 GMT  
 Any discontinued S/360 appl. instructions?
While we are praising the 360/67, there was the SLT, Search List instruction.
Quote:


> <snip>

> > Well, yes, actually there have been a few instructions which have
> > been dropped, although I'm not sure if they count.  The ones I'm
> > thinking of were the Branch and Store (BAS/BASR) instructions
> > (Opcode 0D/4D) that were present on the S/360 (model 67 only?), but
> > had disappeared from the S/370 instruction set.  These were
> > resurrected as the Branch and Save (BAS/BASR) instructions (Opcodes
> > 0D/4D) on the 370/XA machines.

> Yes, I believe those were /67 only.  The replacements behave identically as far
> as I can tell.  Another legacy from that fine architecture.

> > There were also instructions like ISK and SSK (Insert Storage Key
> > and Set Storage Key) which were present on the S/360, but have
> > disappeared on the ESA/390 machines (having been replaced by the
> > ISKE and SSKE instructions).  But, since these are (semi-)
> > privileged, I'm not sure they count.

> ISK/SSK were privileged.

> > Plus, some of the S/360s supported the WRD and RDD (Write Direct and
> > Read Direct) instructions, which are no longer present in the ESA
> > machines.  My green card indicates that these were not privileged on
> > the S/360 (although that may be a typo, which, unfortunately I can't
> > verify since my S/360 Pops is in storage), although they were
> > privileged on the S/370.  What's interesting is that the opcodes for
> > these were reused in the ESA machines.

> These are actually quite interesting.  WRD/RDD were privileged and a (object)
> program that used them would be quite surprised on modern machines since the
> opcodes are now X'85'=BRXLE and X'84'=BRXH!

> > There were also the STMC and LMC (STore Multiple Control and Load
> > Multiple Control) instructions on the S/360 (model 67 only?), which
> > disappeared for the S/370, but, again, these are privileged.

> Again yes, /67 instructions.

> > Of course, all of the I/O instructions disappeared with the switch
> > to XA, but, since those are privileged, they don't count.

> > Somewhere, I have a chart of all of the instructions which existed
> > on the S/360-ESA/390 machines.  Note that there were LOTS of
> > instructions which never made the Pops, instead being documented in
> > various extensions manuals.  I'll see if I can dig the list up if
> > anyone is interested (And, it only lists documented instructions;
> > no undocumented/unannounced instructions are in it.).

> There still are.  CSP is only documented in an online addendum to the PoO, for
> example.

> > Dave

> > P.S. Standard Disclaimer: I work for them, but I don't speak for them.

> Bob



Mon, 17 Feb 2003 09:59:24 GMT  
 Any discontinued S/360 appl. instructions?

Quote:

> While we are praising the 360/67, there was the SLT, Search List instruction.

<snip>

Yes, but it was not standard on the machine; it was RPQ.

Bob



Mon, 17 Feb 2003 22:15:05 GMT  
 Any discontinued S/360 appl. instructions?
In general, if I find some old (ie late 1960s) texts with sample
assembler programs in them, I could be confident they will still work
as coded.  It appears that all changed instructions were only
specialized ones on advanced machines, not the mainstay equipment.


Mon, 17 Feb 2003 22:27:41 GMT  
 
 [ 13 post ] 

 Relevant Pages 

1. Search List (SLT) instruction on 360/67

2. IBM 360 Emulator

3. IBM 360 Emulator

4. Assembly Source for APL\360

5. APL\360 Computers

6. 360/40 APL RPQ

7. APL/360 Computers

8. S/360-Z series timings, then and now?

9. SPITBOL 360, a SNOBOL4 Compiler, Re-released Under GPL

10. ASM/360 tutorial

11. S/360-390 64 bit?

12. Complex Numbers from APL\360

 

 
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