6 Feb
2026
6 Feb
'26
12:30 a.m.
Hey all,
I was trying to track down some kind of image/photo of "what IBM VM/370
looks like" (the operating system)
I tried looking also in the IBM manuals - I'm just not finding much. Some
kind of image of what maybe a remote login looked like, a task process
list, or maybe basic file/folder management commands, or how an editor or
programming worked on that system.
There is a bit of media with a VM/370 emulator, but I wasn't sure how
accurately representative it was of a kind of "look and feel" of that OS.
What I'd need is maybe photographs of teletype printouts? This was still
early 1970s. Which is understandable not much of that was probably kept
around.
Thanks, just digging around - like wasn't sure if VM/370 was still
six-character filename limited like earlier 60s era OS's, or whatever
characteristics it had in operating it.
-Steve
6 Feb
6 Feb
4:32 a.m.
On 06/02/2026 08:30, Steve Lewis via cctalk wrote:
Hey all,
I was trying to track down some kind of image/photo of "what IBM VM/370
looks like" (the operating system)
Well its software, so its hard to say what it looks like!
Seriously it changed a lot over the years, and so you need to say
"when", oh I see from below 1970s.....
I tried looking also in the IBM manuals - I'm just
not finding much. Some
kind of image of what maybe a remote login looked like, a task process
list, or maybe basic file/folder management commands, or how an editor or
programming worked on that system.
There is no "Task/process" list. VM , more usually called CP creates a
virtual machine for each user.
The user then IPLs CMS into that virtual machine, hence VM/370 -. every
one gets a virtual 370 or VM/CMS most people run CMS in their virtual
machine.
so you can do a query names which shows you who is logged on...
query names
OPERATOR - 009, WAKEUP - DSC, CMSBATCH - DSC, CPWATCH - DSC
MAINT - 0C1, CMSUSER - 0C0
Ready; T=0.01/0.01 12:27:04
and use the indicate command to see how the machine is performing...
indicate load
CPU-002% APU-000% Q1-00 Q2-00 STORAGE-012% RATIO-01.0
Ready; T=0.01/0.01 12:29:07
indicate user
PAGES: RES-0119 WS-0059 READS=000019 WRITES=000000 DISK-0000 DRUM-0000
VTIME=000:01 TTIME=000:02 SIO=001039 RDR-000000 PRT-000000 PCH-000000
Ready; T=0.01/0.01 12:30:07
There is a bit of media with a VM/370 emulator, but I
wasn't sure how
accurately representative it was of a kind of "look and feel" of that OS.
probably representative, but its hard to say what is realistic. Many
sites had one extensions in the form of SEPP or BSEPP which were
licenced from IBM and appear to be lost.
Those that didn't have those wrote their own extensions, many of which
have been preserved.
What I'd need is maybe photographs of teletype
printouts? This was still
early 1970s. Which is understandable not much of that was probably kept
around.
no one used a teletype on VM/370, and in the 1970s it was VM/370. Almost
always a 3270 screen or a 2741 but not many 2741.
I think most common reason for a 2741 was that you were running APL.
/I know at this point some one will pop-in and say they did, but it was
really rare./
Thanks, just digging around - like wasn't sure if
VM/370 was still
six-character filename limited like earlier 60s era OS's, or whatever
characteristics it had in operating it.
It is even weirder. There are no folders or directories, just
8-character file name, 8-character file type, and file mode, so a disk
letter and sort of permissions number. e.g.
list ab* * a
ABSLDR ASSEMBLE A1
ABSLDR LISTING A1
ABSLDR TEXT A1
ABSTRACT ABS3 A1
ABSTRACT ABS5 A1
ABSTRACT P3 A1
ABSTRACT R5 A1
ABSTRACT R6 A1
ABSTRACT R6A A1
ABSTRACT WATER2 A1
Ready; T=0.01/0.01 12:17:27
and just to confuse things
files of type "TEXT" or the equivalent of "OBJECT" files in most other
systems.
-Steve
Dave
6:55 a.m.
Thanks Dave, the 3270 terminal screen makes sense. Or to make use of the
system and resources, you'd remote to it using a 3270.
So it may have been at a time no one thought to snap a photograph of any of
those 3270s in use (not just a "room full of 3270's" kind of photo - but of
the actual screen, showing whatever it was they were doing; managing
tape/disk resources, files, users, or running APL or something. That's
more what I was looking for, when you "used VM/370 {or remoted into it},
this is what it looked like."
There had to be some kind of installer? Or maybe I'm viewing it wrong -
they (a business) didn't just buy a S/370 then decide what OS to install.
But rather it was a packaged prepared by IBM, so maybe it was pre-installed
with VM/370 and configured to whatever the arrangement/contract was? Or a
way to say "when someone used a S/370 {or CMS}, this is what the console
content looked like" (printed, or by that time yea probably more likely a
CRT).
“The Origin of the VM/370 Time-Sharing System” – R.J. Creasy gives a little
bit of a description on those components CP, CMS, and RSCS. But no
photo/image yet of a terminal with content to identify "yeah, see they are
using a S/370 there" (maybe its listing disk packs, tapes, memory
resources, etc?) I got something like this for the earlier CTSS and
TOPS-10.
-Steve
On Fri, Feb 6, 2026 at 6:32 AM David Wade via cctalk <cctalk(a)classiccmp.org>
wrote:
On 06/02/2026 08:30, Steve Lewis via cctalk wrote:
Hey all,
I was trying to track down some kind of image/photo of "what IBM VM/370
looks like" (the operating system)
Well its software, so its hard to say what it looks like!
Seriously it changed a lot over the years, and so you need to say
"when", oh I see from below 1970s.....
I tried looking also in the IBM manuals - I'm
just not finding much.
Some
kind of image of what maybe a remote login looked
like, a task process
list, or maybe basic file/folder management commands, or how an editor or
programming worked on that system.
There is no "Task/process" list. VM , more usually called CP creates a
virtual machine for each user.
The user then IPLs CMS into that virtual machine, hence VM/370 -. every
one gets a virtual 370 or VM/CMS most people run CMS in their virtual
machine.
so you can do a query names which shows you who is logged on...
query names
OPERATOR - 009, WAKEUP - DSC, CMSBATCH - DSC, CPWATCH - DSC
MAINT - 0C1, CMSUSER - 0C0
Ready; T=0.01/0.01 12:27:04
and use the indicate command to see how the machine is performing...
indicate load
CPU-002% APU-000% Q1-00 Q2-00 STORAGE-012% RATIO-01.0
Ready; T=0.01/0.01 12:29:07
indicate user
PAGES: RES-0119 WS-0059 READS=000019 WRITES=000000 DISK-0000 DRUM-0000
VTIME=000:01 TTIME=000:02 SIO=001039 RDR-000000 PRT-000000 PCH-000000
Ready; T=0.01/0.01 12:30:07
There is a bit of media with a VM/370 emulator,
but I wasn't sure how
accurately representative it was of a kind of "look and feel" of that OS.
probably representative, but its hard to say what is realistic. Many
sites had one extensions in the form of SEPP or BSEPP which were
licenced from IBM and appear to be lost.
Those that didn't have those wrote their own extensions, many of which
have been preserved.
What I'd need is maybe photographs of
teletype printouts? This was still
early 1970s. Which is understandable not much of that was probably kept
around.
no one used a teletype on VM/370, and in the 1970s it was VM/370. Almost
always a 3270 screen or a 2741 but not many 2741.
I think most common reason for a 2741 was that you were running APL.
/I know at this point some one will pop-in and say they did, but it was
really rare./
Thanks, just digging around - like wasn't
sure if VM/370 was still
six-character filename limited like earlier 60s era OS's, or whatever
characteristics it had in operating it.
It is even weirder. There are no folders or directories, just
8-character file name, 8-character file type, and file mode, so a disk
letter and sort of permissions number. e.g.
list ab* * a
ABSLDR ASSEMBLE A1
ABSLDR LISTING A1
ABSLDR TEXT A1
ABSTRACT ABS3 A1
ABSTRACT ABS5 A1
ABSTRACT P3 A1
ABSTRACT R5 A1
ABSTRACT R6 A1
ABSTRACT R6A A1
ABSTRACT WATER2 A1
Ready; T=0.01/0.01 12:17:27
and just to confuse things
files of type "TEXT" or the equivalent of "OBJECT" files in most
other
systems.
-Steve
Dave
8 a.m.
On 06/02/2026 14:55, Steve Lewis wrote:
Thanks Dave, the 3270 terminal screen makes sense. Or
to make use of
the system and resources, you'd remote to it using a 3270.
So it may have been at a time no one thought to snap a photograph of
any of those 3270s in use (not just a "room full of 3270's" kind of
photo - but of the actual screen, showing whatever it was they were
doing; managing tape/disk resources, files, users, or running APL or
something. That's more what I was looking for, when you "used VM/370
{or remoted into it}, this is what it looked like."
Generally thats not what
you did with VM/370. You edited, compiled, and
ran programs....
There had to be some kind of installer? Or maybe I'm viewing it wrong
- they (a business) didn't just buy a S/370 then decide what OS to
install. But rather it was a packaged prepared by IBM, so maybe it
was pre-installed with VM/370 and configured to whatever the
arrangement/contract was?
For VM you usually got a "starter system" on a tape. There was a
different tape for each disk type. The first file on the tape is the
standalone disk dump and restore program, DDR. So you IPL (boot) from
this tape, and use DDR to restore the starter system to DASD (disk).
You usually needed three packs. The first time you IPL the restored
starter system it asks you some basic config questions, and you then
have a working system that you can use to restore the rest of the
VM/370, load and apply service (fixes) , and configure to your exact
hardware set-up.
I expect at 522 pages this manual which covers install and congigureis a
tad bigger than the one for other systems...
https://bitsavers.org/pdf/ibm/370/VM/370/Release_6/GC20-1801-10_VM370_Sysge…
Or a way to say "when someone used a S/370 {or
CMS}, this is what the
console content looked like" (printed, or by that time yea probably
more likely a CRT).
It looked like whatever you wanted. The samples in the previous e-mail
are typical...
“The Origin of the VM/370 Time-Sharing System” – R.J.
Creasy gives a
little bit of a description on those components CP, CMS, and RSCS.
But no photo/image yet of a terminal with content to identify "yeah,
see they are using a S/370 there" (maybe its listing disk packs,
tapes, memory resources, etc?) I got something like this for the
earlier CTSS and TOPS-10.
pass me what you have for that so I can see what a VM Equivalent might
be. The definitive thing on a users 3270 is the status bottom right
which on a pukka system which usually reads "VM READ VM/370" but can
also start "RUNNING", "HOLDING" "CP READ".
-Steve
Dave
7:51 p.m.
Dave,
Page 439 of that document you linked has a nice chart of "integrated
emulators that run execute under VM/370" - now I do recall one of the
"famous" things about the prior S/360 was it could emulate 1401 and other
IBM systems. Then later on, more systems to emulate would be the
709-series. Ok, so VM/370 is more like what we might today call a
Hypervisor? So the "it looks like whatever you want" comment makes
sense.
I suppose what I'm after is more a visual on the usage of CMS, DOS/VS or
OS/VS1 ( OS's that one would only use on an S/370 ? )
I put a couple reference images here on what I have about CTSS and TOPS-10
(CTSS is from a modern-day emulators, TOPS-10 is from one of their manuals
so its from in 1970). I see how you mean VM/370 isn't quite the same
nature (not "just an OS" but an enterprise thing like for airlines, banks,
financial brokers -- and the virtualization helped in testing/deploying new
systems -- that maybe had newer OS's -- without disrupting operational
systems?)
https://github.com/voidstar78/OS_NOTES
- Steve
On Fri, Feb 6, 2026 at 10:00 AM David Wade <dave.g4ugm(a)gmail.com> wrote:
On 06/02/2026 14:55, Steve Lewis wrote:
Thanks Dave, the 3270 terminal screen makes
sense. Or to make use of
the system and resources, you'd remote to it using a 3270.
So it may have been at a time no one thought to snap a photograph of
any of those 3270s in use (not just a "room full of 3270's" kind of
photo - but of the actual screen, showing whatever it was they were
doing; managing tape/disk resources, files, users, or running APL or
something. That's more what I was looking for, when you "used VM/370
{or remoted into it}, this is what it looked like."
Generally thats not what you did with VM/370. You edited, compiled, and
ran programs....
There had to be some kind of installer? Or maybe I'm viewing it wrong
- they (a business) didn't just buy a S/370 then decide what OS to
install. But rather it was a packaged prepared by IBM, so maybe it
was pre-installed with VM/370 and configured to whatever the
arrangement/contract was?
For VM you usually got a "starter system" on a tape. There was a
different tape for each disk type. The first file on the tape is the
standalone disk dump and restore program, DDR. So you IPL (boot) from
this tape, and use DDR to restore the starter system to DASD (disk).
You usually needed three packs. The first time you IPL the restored
starter system it asks you some basic config questions, and you then
have a working system that you can use to restore the rest of the
VM/370, load and apply service (fixes) , and configure to your exact
hardware set-up.
I expect at 522 pages this manual which covers install and congigureis a
tad bigger than the one for other systems...
https://bitsavers.org/pdf/ibm/370/VM/370/Release_6/GC20-1801-10_VM370_Sysge…
Or a way to say "when someone used a S/370
{or CMS}, this is what the
console content looked like" (printed, or by that time yea probably
more likely a CRT).
It looked like whatever you wanted. The samples in the previous e-mail
are typical...
“The Origin of the VM/370 Time-Sharing System” –
R.J. Creasy gives a
little bit of a description on those components CP, CMS, and RSCS.
But no photo/image yet of a terminal with content to identify "yeah,
see they are using a S/370 there" (maybe its listing disk packs,
tapes, memory resources, etc?) I got something like this for the
earlier CTSS and TOPS-10.
pass me what you have for that so I can see what a VM Equivalent might
be. The definitive thing on a users 3270 is the status bottom right
which on a pukka system which usually reads "VM READ VM/370" but can
also start "RUNNING", "HOLDING" "CP READ".
-Steve
Dave
8 p.m.
You could run different jobs at the same time in different partitions. Just had to make
sure the jobs didn’t need the same resources or you would get a lock. So if a jobs needed
a certain tape, make sure another job running in another partition didn’t need it.
Sent from my iPhone
On Feb 6, 2026, at 19:51, Steve Lewis via cctalk
<cctalk(a)classiccmp.org> wrote:
Dave,
Page 439 of that document you linked has a nice chart of "integrated
emulators that run execute under VM/370" - now I do recall one of the
"famous" things about the prior S/360 was it could emulate 1401 and other
IBM systems. Then later on, more systems to emulate would be the
709-series. Ok, so VM/370 is more like what we might today call a
Hypervisor? So the "it looks like whatever you want" comment makes
sense.
I suppose what I'm after is more a visual on the usage of CMS, DOS/VS or
OS/VS1 ( OS's that one would only use on an S/370 ? )
I put a couple reference images here on what I have about CTSS and TOPS-10
(CTSS is from a modern-day emulators, TOPS-10 is from one of their manuals
so its from in 1970). I see how you mean VM/370 isn't quite the same
nature (not "just an OS" but an enterprise thing like for airlines, banks,
financial brokers -- and the virtualization helped in testing/deploying new
systems -- that maybe had newer OS's -- without disrupting operational
systems?)
https://github.com/voidstar78/OS_NOTES
- Steve
> On Fri, Feb 6, 2026 at 10:00 AM David Wade <dave.g4ugm(a)gmail.com> wrote:
>
>
>
>> On 06/02/2026 14:55, Steve Lewis wrote:
>> Thanks Dave, the 3270 terminal screen makes sense. Or to make use of
>> the system and resources, you'd remote to it using a 3270.
>> So it may have been at a time no one thought to snap a photograph of
>> any of those 3270s in use (not just a "room full of 3270's" kind of
>> photo - but of the actual screen, showing whatever it was they were
>> doing; managing tape/disk resources, files, users, or running APL or
>> something. That's more what I was looking for, when you "used VM/370
>> {or remoted into it}, this is what it looked like."
> Generally thats not what you did with VM/370. You edited, compiled, and
> ran programs....
>
>>
>> There had to be some kind of installer? Or maybe I'm viewing it wrong
>> - they (a business) didn't just buy a S/370 then decide what OS to
>> install. But rather it was a packaged prepared by IBM, so maybe it
>> was pre-installed with VM/370 and configured to whatever the
>> arrangement/contract was?
>
> For VM you usually got a "starter system" on a tape. There was a
> different tape for each disk type. The first file on the tape is the
> standalone disk dump and restore program, DDR. So you IPL (boot) from
> this tape, and use DDR to restore the starter system to DASD (disk).
> You usually needed three packs. The first time you IPL the restored
> starter system it asks you some basic config questions, and you then
> have a working system that you can use to restore the rest of the
> VM/370, load and apply service (fixes) , and configure to your exact
> hardware set-up.
>
> I expect at 522 pages this manual which covers install and congigureis a
> tad bigger than the one for other systems...
>
>
>
https://bitsavers.org/pdf/ibm/370/VM/370/Release_6/GC20-1801-10_VM370_Sysge…
>
>
>> Or a way to say "when someone used a S/370 {or CMS}, this is what the
>> console content looked like" (printed, or by that time yea probably
>> more likely a CRT).
>>
>
> It looked like whatever you wanted. The samples in the previous e-mail
> are typical...
>
>
>> “The Origin of the VM/370 Time-Sharing System” – R.J. Creasy gives a
>> little bit of a description on those components CP, CMS, and RSCS.
>> But no photo/image yet of a terminal with content to identify "yeah,
>> see they are using a S/370 there" (maybe its listing disk packs,
>> tapes, memory resources, etc?) I got something like this for the
>> earlier CTSS and TOPS-10.
>>
> pass me what you have for that so I can see what a VM Equivalent might
> be. The definitive thing on a users 3270 is the status bottom right
> which on a pukka system which usually reads "VM READ VM/370" but can
> also start "RUNNING", "HOLDING" "CP READ".
>
>> -Steve
>>
>>
> Dave
>
8:12 p.m.
Stuff i’m kinda remembering now.
CMS was an acronym for Conversational Monitor System.
You could write short programs using a scripting language, i think it was called REXX.
Sent from my iPhone
On Feb 6, 2026, at 20:00, Wayne S
<wayne.sudol(a)hotmail.com> wrote:
You could run different jobs at the same time in different partitions. Just had to make
sure the jobs didn’t need the same resources or you would get a lock. So if a jobs needed
a certain tape, make sure another job running in another partition didn’t need it.
Sent from my iPhone
> On Feb 6, 2026, at 19:51, Steve Lewis via cctalk <cctalk(a)classiccmp.org> wrote:
>
> Dave,
>
> Page 439 of that document you linked has a nice chart of "integrated
> emulators that run execute under VM/370" - now I do recall one of the
> "famous" things about the prior S/360 was it could emulate 1401 and other
> IBM systems. Then later on, more systems to emulate would be the
> 709-series. Ok, so VM/370 is more like what we might today call a
> Hypervisor? So the "it looks like whatever you want" comment makes
> sense.
>
> I suppose what I'm after is more a visual on the usage of CMS, DOS/VS or
> OS/VS1 ( OS's that one would only use on an S/370 ? )
>
> I put a couple reference images here on what I have about CTSS and TOPS-10
> (CTSS is from a modern-day emulators, TOPS-10 is from one of their manuals
> so its from in 1970). I see how you mean VM/370 isn't quite the same
> nature (not "just an OS" but an enterprise thing like for airlines, banks,
> financial brokers -- and the virtualization helped in testing/deploying new
> systems -- that maybe had newer OS's -- without disrupting operational
> systems?)
>
> https://github.com/voidstar78/OS_NOTES
>
>
> - Steve
>
>
>
>
>>> On Fri, Feb 6, 2026 at 10:00 AM David Wade <dave.g4ugm(a)gmail.com>
wrote:
>>
>>
>>
>>> On 06/02/2026 14:55, Steve Lewis wrote:
>>> Thanks Dave, the 3270 terminal screen makes sense. Or to make use of
>>> the system and resources, you'd remote to it using a 3270.
>>> So it may have been at a time no one thought to snap a photograph of
>>> any of those 3270s in use (not just a "room full of 3270's"
kind of
>>> photo - but of the actual screen, showing whatever it was they were
>>> doing; managing tape/disk resources, files, users, or running APL or
>>> something. That's more what I was looking for, when you "used
VM/370
>>> {or remoted into it}, this is what it looked like."
>> Generally thats not what you did with VM/370. You edited, compiled, and
>> ran programs....
>>
>>>
>>> There had to be some kind of installer? Or maybe I'm viewing it wrong
>>> - they (a business) didn't just buy a S/370 then decide what OS to
>>> install. But rather it was a packaged prepared by IBM, so maybe it
>>> was pre-installed with VM/370 and configured to whatever the
>>> arrangement/contract was?
>>
>> For VM you usually got a "starter system" on a tape. There was a
>> different tape for each disk type. The first file on the tape is the
>> standalone disk dump and restore program, DDR. So you IPL (boot) from
>> this tape, and use DDR to restore the starter system to DASD (disk).
>> You usually needed three packs. The first time you IPL the restored
>> starter system it asks you some basic config questions, and you then
>> have a working system that you can use to restore the rest of the
>> VM/370, load and apply service (fixes) , and configure to your exact
>> hardware set-up.
>>
>> I expect at 522 pages this manual which covers install and congigureis a
>> tad bigger than the one for other systems...
>>
>>
>>
https://bitsavers.org/pdf/ibm/370/VM/370/Release_6/GC20-1801-10_VM370_Sysge…
>>
>>
>>> Or a way to say "when someone used a S/370 {or CMS}, this is what the
>>> console content looked like" (printed, or by that time yea probably
>>> more likely a CRT).
>>>
>>
>> It looked like whatever you wanted. The samples in the previous e-mail
>> are typical...
>>
>>
>>> “The Origin of the VM/370 Time-Sharing System” – R.J. Creasy gives a
>>> little bit of a description on those components CP, CMS, and RSCS.
>>> But no photo/image yet of a terminal with content to identify "yeah,
>>> see they are using a S/370 there" (maybe its listing disk packs,
>>> tapes, memory resources, etc?) I got something like this for the
>>> earlier CTSS and TOPS-10.
>>>
>> pass me what you have for that so I can see what a VM Equivalent might
>> be. The definitive thing on a users 3270 is the status bottom right
>> which on a pukka system which usually reads "VM READ VM/370" but can
>> also start "RUNNING", "HOLDING" "CP READ".
>>
>>> -Steve
>>>
>>>
>> Dave
>>
7 Feb
7 Feb
12:29 a.m.
what I miss is cmspipelines. pipeline on steriods. lables, fan streams to
multiple named pipes, collect named pipes in elsewhere.
someone wrote a whole master file transaction update system and i think a
payroll process system system in ONE pipeline, with continusitons over 100s
of lines. I'd be happy with 5% of it in linux/unix.
heck, I'd like exec2 in linux, many thing could be done very simply and
easily.
<https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail>
Virus-free.www.avast.com
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<#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
On Sat, Feb 7, 2026 at 2:08 AM r.stricklin via cctalk <cctalk(a)classiccmp.org>
wrote:
--
--Carey
On Feb 6, 2026, at 8:12 PM, Wayne S via cctalk
<cctalk(a)classiccmp.org>
wrote:
You could write short programs using a scripting language, i think it
was called REXX.
REXX was added in VM/SP R2 or so. Older systems had EXEC2, and before
that, EXEC.
ok
bear.
5:36 p.m.
what I miss is cmspipelines. pipeline on steriods.
lables, fan streams to
multiple named pipes, collect named pipes in elsewhere.
Someone wrote a UNIX implementation of this. I forget its name,
but some duckduckgoing should turn it up.
I downloaded and compiled it and played with it a little bit. It's
a fascinating bit of code, but I didn't have any time to investigate
it further. From my minimal reading of the documentation, it looked
very powreful and flexible in what it could do.
--lyndon
12:21 a.m.
VM included CP and CMS. CP ran on the hardware and created virtual
machines. CMS ran in a virtual machine and intereacted with users, but
could not run on the real hardware (though the very early versions
purportedly could). native timesharing and batch jobs each run under CMS
on a virtual machine
BUT, in the virtual machines, you could also run...
--DOS/VS the operating system that ran on the smaller IBM mainframes
--OS/VS1 the operating system that ran on mid-range hardware, similar to
what ran on larger system 360 machines, with one continuous virtual storage
--OS/VS2 which ran on largest hardware, each user or batch job got the same
address range
--VM/370....which could again run all of the above
...as deep as you wanted. somebody got a system to IPL (boot) like 20-some
levels deep. it got slower and slower each level you went, of course as
everything got paged in and out to do anything.
the instruction to store the cpu id was modified in a virtual machine to
put a hex FF in the last byte because otherwise there was NO WAY to tell if
you were running on real hardware or in a virtual job under CP, other than
a timing loop.
this is why i am dissatisfied with virtualization on intel hardware. to
many things DO NOT WORK unless the hypervisor knows it has to fake
something to make the virtual machine work, and i cannot do a base install
in a virtual machine of any random install media
<https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail>
Virus-free.www.avast.com
<https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail>
<#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
On Fri, Feb 6, 2026 at 10:12 PM Wayne S via cctalk <cctalk(a)classiccmp.org>
wrote:
Stuff i’m kinda remembering now.
CMS was an acronym for Conversational Monitor System.
You could write short programs using a scripting language, i think it was
called REXX.
Sent from my iPhone
--
--Carey
On Feb 6, 2026, at 20:00, Wayne S
<wayne.sudol(a)hotmail.com> wrote:
You could run different jobs at the same time in different partitions.
Just had to make sure the jobs didn’t need the same resources or you would
get a lock. So if a jobs needed a certain tape, make sure another job
running in another partition didn’t need it.
Sent from my iPhone
> On Feb 6, 2026, at 19:51, Steve Lewis via cctalk <cctalk(a)classiccmp.org>
wrote:
>
> Dave,
>
> Page 439 of that document you linked has a nice chart of "integrated
> emulators that run execute under VM/370" - now I do recall one of the
> "famous" things about the prior S/360 was it could emulate 1401 and
other
> IBM systems. Then later on, more systems to
emulate would be the
> 709-series. Ok, so VM/370 is more like what we might today call a
> Hypervisor? So the "it looks like whatever you want" comment makes
> sense.
>
> I suppose what I'm after is more a visual on the usage of CMS, DOS/VS or
> OS/VS1 ( OS's that one would only use on an S/370 ? )
>
> I put a couple reference images here on what I have about CTSS and
TOPS-10
> (CTSS is from a modern-day emulators, TOPS-10
is from one of their
manuals
> so its from in 1970). I see how you mean
VM/370 isn't quite the same
> nature (not "just an OS" but an enterprise thing like for airlines,
banks,
> financial brokers -- and the virtualization
helped in testing/deploying
new
> systems -- that maybe had newer OS's --
without disrupting operational
> systems?)
>
> https://github.com/voidstar78/OS_NOTES
>
>
> - Steve
>
>
>
>
>>> On Fri, Feb 6, 2026 at 10:00 AM David Wade <dave.g4ugm(a)gmail.com>
wrote:
>>
>>
>>
>>> On 06/02/2026 14:55, Steve Lewis wrote:
>>> Thanks Dave, the 3270 terminal screen makes sense. Or to make use of
>>> the system and resources, you'd remote to it using a 3270.
>>> So it may have been at a time no one thought to snap a photograph of
>>> any of those 3270s in use (not just a "room full of 3270's"
kind of
>>> photo - but of the actual screen, showing whatever it was they were
>>> doing; managing tape/disk resources, files, users, or running APL or
>>> something. That's more what I was looking for, when you "used
VM/370
>>> {or remoted into it}, this is what it looked like."
>> Generally thats not what you did with VM/370. You edited, compiled, and
>> ran programs....
>>
>>>
>>> There had to be some kind of installer? Or maybe I'm viewing it wrong
>>> - they (a business) didn't just buy a S/370 then decide what OS to
>>> install. But rather it was a packaged prepared by IBM, so maybe it
>>> was pre-installed with VM/370 and configured to whatever the
>>> arrangement/contract was?
>>
>> For VM you usually got a "starter system" on a tape. There was a
>> different tape for each disk type. The first file on the tape is the
>> standalone disk dump and restore program, DDR. So you IPL (boot) from
>> this tape, and use DDR to restore the starter system to DASD (disk).
>> You usually needed three packs. The first time you IPL the restored
>> starter system it asks you some basic config questions, and you then
>> have a working system that you can use to restore the rest of the
>> VM/370, load and apply service (fixes) , and configure to your exact
>> hardware set-up.
>>
>> I expect at 522 pages this manual which covers install and congigureis
a
>> tad bigger than the one for other
systems...
>>
>>
>>
https://bitsavers.org/pdf/ibm/370/VM/370/Release_6/GC20-1801-10_VM370_Sysge…
>>
>>
>>> Or a way to say "when someone used a S/370 {or CMS}, this is what the
>>> console content looked like" (printed, or by that time yea probably
>>> more likely a CRT).
>>>
>>
>> It looked like whatever you wanted. The samples in the previous e-mail
>> are typical...
>>
>>
>>> “The Origin of the VM/370 Time-Sharing System” – R.J. Creasy gives a
>>> little bit of a description on those components CP, CMS, and RSCS.
>>> But no photo/image yet of a terminal with content to identify "yeah,
>>> see they are using a S/370 there" (maybe its listing disk packs,
>>> tapes, memory resources, etc?) I got something like this for the
>>> earlier CTSS and TOPS-10.
>>>
>> pass me what you have for that so I can see what a VM Equivalent might
>> be. The definitive thing on a users 3270 is the status bottom right
>> which on a pukka system which usually reads "VM READ VM/370" but can
>> also start "RUNNING", "HOLDING" "CP READ".
>>
>>> -Steve
>>>
>>>
>> Dave
>>
1:35 a.m.
On 07/02/2026 03:51, Steve Lewis wrote:
Dave,
Page 439 of that document you linked has a nice chart of "integrated
emulators that run execute under VM/370" - now I do recall one of the
"famous" things about the prior S/360 was it could emulate 1401 and
other IBM systems. Then later on, more systems to emulate would be
the 709-series. Ok, so VM/370 is more like what we might today
call a Hypervisor? So the "it looks like whatever you want" comment
makes sense.
You don't need VM to emulate a 1401, I believe the 1401 emulator ran
under MVS as well, or I think on some S/360 machines you could load 1401
microcode.
So yes VM itself is what today we would call a hypervisor. It creates
virtual machines and each virtual machine is pretty much totally isolated.
But CMS was provided as source code, and in the early days it was very
limited so sites made many modifications.
I suppose what I'm after is more a visual on the
usage of CMS, DOS/VS
or OS/VS1 ( OS's that one would only use on an S/370 ? )
There was also MTS and MUSIC plus a few other TSO and CICS replacements.
I put a couple reference images here on what I have
about CTSS and
TOPS-10 (CTSS is from a modern-day emulators, TOPS-10 is from one of
their manuals so its from in 1970). I see how you mean VM/370 isn't
quite the same nature (not "just an OS" but an enterprise thing like
for airlines, banks, financial brokers -- and the virtualization
helped in testing/deploying new systems -- that maybe had newer OS's
-- without disrupting operational systems?)
https://github.com/voidstar78/OS_NOTES
OK I can do something similar for VM and CMS but got a busy day here:-
https://www.scienceandindustrymuseum.org.uk/whats-on/meet-baby
(yes thats me, the rest of the team are camera shy)
- Steve
Dave
On Fri, Feb 6, 2026 at 10:00 AM David Wade <dave.g4ugm(a)gmail.com> wrote:
On 06/02/2026 14:55, Steve Lewis wrote:
Thanks Dave, the 3270 terminal screen makes
sense. Or to make
use of
the system and resources, you'd remote to it
using a 3270.
So it may have been at a time no one thought to snap a
photograph of
any of those 3270s in use (not just a "room
full of 3270's" kind of
photo - but of the actual screen, showing whatever it was they were
doing; managing tape/disk resources, files, users, or running
APL or
something. That's more what I was looking
for, when you "used
VM/370
{or remoted into it}, this is what it looked
like."
Generally thats not what you did with VM/370. You edited,
compiled, and
ran programs....
There had to be some kind of installer? Or maybe I'm viewing it
wrong
- they (a business) didn't just buy a S/370
then decide what OS to
install. But rather it was a packaged prepared by IBM, so maybe it
was pre-installed with VM/370 and configured to whatever the
arrangement/contract was?
For VM you usually got a "starter system" on a tape. There was a
different tape for each disk type. The first file on the tape is the
standalone disk dump and restore program, DDR. So you IPL (boot) from
this tape, and use DDR to restore the starter system to DASD (disk).
You usually needed three packs. The first time you IPL the restored
starter system it asks you some basic config questions, and you then
have a working system that you can use to restore the rest of the
VM/370, load and apply service (fixes) , and configure to your exact
hardware set-up.
I expect at 522 pages this manual which covers install and
congigureis a
tad bigger than the one for other systems...
https://bitsavers.org/pdf/ibm/370/VM/370/Release_6/GC20-1801-10_VM370_Sysge…
Or a way to say "when someone used a S/370
{or CMS}, this is
what the
console content looked like" (printed, or by
that time yea probably
more likely a CRT).
It looked like whatever you wanted. The samples in the previous
e-mail
are typical...
“The Origin of the VM/370 Time-Sharing System” –
R.J. Creasy
gives a
little bit of a description on those components
CP, CMS, and RSCS.
But no photo/image yet of a terminal with content to identify
"yeah,
see they are using a S/370 there" (maybe its
listing disk packs,
tapes, memory resources, etc?) I got something like this for the
earlier CTSS and TOPS-10.
pass me what you have for that so I can see what a VM Equivalent
might
be. The definitive thing on a users 3270 is the status bottom right
which on a pukka system which usually reads "VM READ VM/370" but can
also start "RUNNING", "HOLDING" "CP READ".
-Steve
Dave
6:42 a.m.
I watched a promo VM/370 movie at Portland state at a nerd fest in 1975.
64 Meg was not believable in 1975. We had 32K on our IBM 1130.
Oregon S/W / OMSI Barry White said, When core gets to $1 a byte, Computers
will take off.
It's funny now.
On Sat, Feb 7, 2026 at 1:36 AM David Wade via cctalk <cctalk(a)classiccmp.org>
wrote:
On 07/02/2026 03:51, Steve Lewis wrote:
Dave,
Page 439 of that document you linked has a nice chart of "integrated
emulators that run execute under VM/370" - now I do recall one of the
"famous" things about the prior S/360 was it could emulate 1401 and
other IBM systems. Then later on, more systems to emulate would be
the 709-series. Ok, so VM/370 is more like what we might today
call a Hypervisor? So the "it looks like whatever you want" comment
makes sense.
You don't need VM to emulate a 1401, I believe the 1401 emulator ran
under MVS as well, or I think on some S/360 machines you could load 1401
microcode.
So yes VM itself is what today we would call a hypervisor. It creates
virtual machines and each virtual machine is pretty much totally isolated.
But CMS was provided as source code, and in the early days it was very
limited so sites made many modifications.
I suppose what I'm after is more a visual on
the usage of CMS, DOS/VS
or OS/VS1 ( OS's that one would only use on an S/370 ? )
There was also MTS and MUSIC plus a few other TSO and CICS replacements.
I put a couple reference images here on what I
have about CTSS and
TOPS-10 (CTSS is from a modern-day emulators, TOPS-10 is from one of
their manuals so its from in 1970). I see how you mean VM/370 isn't
quite the same nature (not "just an OS" but an enterprise thing like
for airlines, banks, financial brokers -- and the virtualization
helped in testing/deploying new systems -- that maybe had newer OS's
-- without disrupting operational systems?)
https://github.com/voidstar78/OS_NOTES
OK I can do something similar for VM and CMS but got a busy day here:-
https://www.scienceandindustrymuseum.org.uk/whats-on/meet-baby
(yes thats me, the rest of the team are camera shy)
- Steve
Dave
On Fri, Feb 6, 2026 at 10:00 AM David Wade <dave.g4ugm(a)gmail.com> wrote:
On 06/02/2026 14:55, Steve Lewis wrote:
https://bitsavers.org/pdf/ibm/370/VM/370/Release_6/GC20-1801-10_VM370_Sysge…
Thanks Dave, the 3270 terminal screen makes
sense. Or to make
use of
the system and resources, you'd remote to it
using a 3270.
So it may have been at a time no one thought to snap a
photograph of
any of those 3270s in use (not just a "room
full of 3270's" kind of
photo - but of the actual screen, showing whatever it was they were
doing; managing tape/disk resources, files, users, or running
APL or
something. That's more what I was looking
for, when you "used
VM/370
{or remoted into it}, this is what it looked
like."
Generally thats not what you did with VM/370. You edited,
compiled, and
ran programs....
There had to be some kind of installer? Or maybe I'm viewing it
wrong
- they (a business) didn't just buy a S/370
then decide what OS to
install. But rather it was a packaged prepared by IBM, so maybe it
was pre-installed with VM/370 and configured to whatever the
arrangement/contract was?
For VM you usually got a "starter system" on a tape. There was a
different tape for each disk type. The first file on the tape is the
standalone disk dump and restore program, DDR. So you IPL (boot) from
this tape, and use DDR to restore the starter system to DASD (disk).
You usually needed three packs. The first time you IPL the restored
starter system it asks you some basic config questions, and you then
have a working system that you can use to restore the rest of the
VM/370, load and apply service (fixes) , and configure to your exact
hardware set-up.
I expect at 522 pages this manual which covers install and
congigureis a
tad bigger than the one for other systems...
Or a way to say "when someone used a S/370
{or CMS}, this is
what the
console content looked like" (printed, or by
that time yea probably
more likely a CRT).
It looked like whatever you wanted. The samples in the previous
e-mail
are typical...
“The Origin of the VM/370 Time-Sharing System” –
R.J. Creasy
gives a
little bit of a description on those components
CP, CMS, and RSCS.
But no photo/image yet of a terminal with content to identify
"yeah,
see they are using a S/370 there" (maybe its
listing disk packs,
tapes, memory resources, etc?) I got something like this for the
earlier CTSS and TOPS-10.
pass me what you have for that so I can see what a VM Equivalent
might
be. The definitive thing on a users 3270 is the status bottom right
which on a pukka system which usually reads "VM READ VM/370" but can
also start "RUNNING", "HOLDING" "CP READ".
-Steve
Dave
6:50 a.m.
We did fruit flies, somebody is trying human reality connection emulation
now.
I think we're screwed.
On Sat, Feb 7, 2026 at 6:42 AM Jim Davis <jim.p.davis(a)gmail.com> wrote:
I watched a promo VM/370 movie at Portland state at a
nerd fest in 1975.
64 Meg was not believable in 1975. We had 32K on our IBM 1130.
Oregon S/W / OMSI Barry White said, When core gets to $1 a byte, Computers
will take off.
It's funny now.
On Sat, Feb 7, 2026 at 1:36 AM David Wade via cctalk <
cctalk(a)classiccmp.org> wrote:
On 07/02/2026 03:51, Steve Lewis wrote:
it
from
probably
Dave,
Page 439 of that document you linked has a nice chart of "integrated
emulators that run execute under VM/370" - now I do recall one of the
"famous" things about the prior S/360 was it could emulate 1401 and
other IBM systems. Then later on, more systems to emulate would be
the 709-series. Ok, so VM/370 is more like what we might today
call a Hypervisor? So the "it looks like whatever you want" comment
makes sense.
You don't need VM to emulate a 1401, I believe the 1401 emulator ran
under MVS as well, or I think on some S/360 machines you could load 1401
microcode.
So yes VM itself is what today we would call a hypervisor. It creates
virtual machines and each virtual machine is pretty much totally isolated.
But CMS was provided as source code, and in the early days it was very
limited so sites made many modifications.
I suppose what I'm after is more a visual on
the usage of CMS, DOS/VS
or OS/VS1 ( OS's that one would only use on an S/370 ? )
There was also MTS and MUSIC plus a few other TSO and CICS replacements.
I put a couple reference images here on what I
have about CTSS and
TOPS-10 (CTSS is from a modern-day emulators, TOPS-10 is from one of
their manuals so its from in 1970). I see how you mean VM/370 isn't
quite the same nature (not "just an OS" but an enterprise thing like
for airlines, banks, financial brokers -- and the virtualization
helped in testing/deploying new systems -- that maybe had newer OS's
-- without disrupting operational systems?)
https://github.com/voidstar78/OS_NOTES
OK I can do something similar for VM and CMS but got a busy day here:-
https://www.scienceandindustrymuseum.org.uk/whats-on/meet-baby
(yes thats me, the rest of the team are camera shy)
- Steve
Dave
On Fri, Feb 6, 2026 at 10:00 AM David Wade <dave.g4ugm(a)gmail.com>
wrote:
On 06/02/2026 14:55, Steve Lewis wrote:
of
Thanks Dave, the 3270 terminal screen makes
sense. Or to make
use of
the system and resources, you'd remote to it
using a 3270.
So it may have been at a time no one thought to snap a
photograph of
> any of those 3270s in use (not just a "room full of 3270's" kind
> photo - but of the actual screen,
showing whatever it was they
were
doing;
managing tape/disk resources, files, users, or running
APL or
something. That's more what I was looking
for, when you "used
VM/370
{or remoted into it}, this is what it looked
like."
Generally thats not what you did with VM/370. You edited,
compiled, and
ran programs....
There had to be some kind of installer? Or maybe I'm viewing it
wrong
> - they (a business) didn't just buy a S/370 then decide what OS to
> install. But rather it was a packaged prepared by IBM, so maybe
was
pre-installed with VM/370 and configured to whatever the
arrangement/contract was?
For VM you usually got a "starter system" on a tape. There was a
different tape for each disk type. The first file on the tape is the
standalone disk dump and restore program, DDR. So you IPL (boot)
this tape, and use DDR to restore the starter
system to DASD
(disk).
You usually needed three packs. The first
time you IPL the restored
starter system it asks you some basic config questions, and you then
have a working system that you can use to restore the rest of the
VM/370, load and apply service (fixes) , and configure to your exact
hardware set-up.
I expect at 522 pages this manual which covers install and
congigureis a
tad bigger than the one for other systems...
https://bitsavers.org/pdf/ibm/370/VM/370/Release_6/GC20-1801-10_VM370_Sysge…
Or a way to say "when someone used a S/370
{or CMS}, this is
what the
> console content looked like" (printed, or by that time yea
more
likely a CRT).
It looked like whatever you wanted. The samples in the previous
e-mail
are typical...
“The Origin of the VM/370 Time-Sharing System” –
R.J. Creasy
gives a
little bit of a description on those components
CP, CMS, and RSCS.
But no photo/image yet of a terminal with content to identify
"yeah,
see they are using a S/370 there" (maybe its
listing disk packs,
tapes, memory resources, etc?) I got something like this for the
earlier CTSS and TOPS-10.
pass me what you have for that so I can see what a VM Equivalent
might
be. The definitive thing on a users 3270 is the status bottom right
which on a pukka system which usually reads "VM READ VM/370" but can
also start "RUNNING", "HOLDING" "CP READ".
-Steve
Dave
11:44 a.m.
the 1401 (1410/1440/7010/etc) emulators were microcode. an extra cost for
the microcode and probably another extra cost for the read only storage for
the extra microcode.
Initially, on the 360s, you could push buttons on the console, and have one
or more 14xx series machines if you had enough memory. perhaps with 370s
too.
then you could IPL a card deck with a minimal 360 in-memory operating
system, and run one or more 14xx series machines with console commands (I
think, I never did this)
'
THen you could run a program in one of the dos partitions (BG,F1.F2) that
would dynamically start a 1401 job by reading in the 14xx program from
cards, while running a native 360 program in the other partition, all as
batch jobs scheduled by reading them into the card reader There was also
1620 emulation and maybe others.,
By the time my employer got to 370 I think they had gotten rid of the 14xx
emulation, but they were availble.
On Sat, Feb 7, 2026 at 3:36 AM David Wade via cctalk <cctalk(a)classiccmp.org>
wrote:
On 07/02/2026 03:51, Steve Lewis wrote:
--
--Carey
Dave,
Page 439 of that document you linked has a nice chart of "integrated
emulators that run execute under VM/370" - now I do recall one of the
"famous" things about the prior S/360 was it could emulate 1401 and
other IBM systems. Then later on, more systems to emulate would be
the 709-series. Ok, so VM/370 is more like what we might today
call a Hypervisor? So the "it looks like whatever you want" comment
makes sense.
You don't need VM to emulate a 1401, I believe the 1401 emulator ran
under MVS as well, or I think on some S/360 machines you could load 1401
microcode.
So yes VM itself is what today we would call a hypervisor. It creates
virtual machines and each virtual machine is pretty much totally isolated.
But CMS was provided as source code, and in the early days it was very
limited so sites made many modifications.
I suppose what I'm after is more a visual on
the usage of CMS, DOS/VS
or OS/VS1 ( OS's that one would only use on an S/370 ? )
There was also MTS and MUSIC plus a few other TSO and CICS replacements.
I put a couple reference images here on what I
have about CTSS and
TOPS-10 (CTSS is from a modern-day emulators, TOPS-10 is from one of
their manuals so its from in 1970). I see how you mean VM/370 isn't
quite the same nature (not "just an OS" but an enterprise thing like
for airlines, banks, financial brokers -- and the virtualization
helped in testing/deploying new systems -- that maybe had newer OS's
-- without disrupting operational systems?)
https://github.com/voidstar78/OS_NOTES
OK I can do something similar for VM and CMS but got a busy day here:-
https://www.scienceandindustrymuseum.org.uk/whats-on/meet-baby
(yes thats me, the rest of the team are camera shy)
- Steve
Dave
On Fri, Feb 6, 2026 at 10:00 AM David Wade <dave.g4ugm(a)gmail.com> wrote:
On 06/02/2026 14:55, Steve Lewis wrote:
https://bitsavers.org/pdf/ibm/370/VM/370/Release_6/GC20-1801-10_VM370_Sysge…
Thanks Dave, the 3270 terminal screen makes
sense. Or to make
use of
the system and resources, you'd remote to it
using a 3270.
So it may have been at a time no one thought to snap a
photograph of
any of those 3270s in use (not just a "room
full of 3270's" kind of
photo - but of the actual screen, showing whatever it was they were
doing; managing tape/disk resources, files, users, or running
APL or
something. That's more what I was looking
for, when you "used
VM/370
{or remoted into it}, this is what it looked
like."
Generally thats not what you did with VM/370. You edited,
compiled, and
ran programs....
There had to be some kind of installer? Or maybe I'm viewing it
wrong
- they (a business) didn't just buy a S/370
then decide what OS to
install. But rather it was a packaged prepared by IBM, so maybe it
was pre-installed with VM/370 and configured to whatever the
arrangement/contract was?
For VM you usually got a "starter system" on a tape. There was a
different tape for each disk type. The first file on the tape is the
standalone disk dump and restore program, DDR. So you IPL (boot) from
this tape, and use DDR to restore the starter system to DASD (disk).
You usually needed three packs. The first time you IPL the restored
starter system it asks you some basic config questions, and you then
have a working system that you can use to restore the rest of the
VM/370, load and apply service (fixes) , and configure to your exact
hardware set-up.
I expect at 522 pages this manual which covers install and
congigureis a
tad bigger than the one for other systems...
Or a way to say "when someone used a S/370
{or CMS}, this is
what the
console content looked like" (printed, or by
that time yea probably
more likely a CRT).
It looked like whatever you wanted. The samples in the previous
e-mail
are typical...
“The Origin of the VM/370 Time-Sharing System” –
R.J. Creasy
gives a
little bit of a description on those components
CP, CMS, and RSCS.
But no photo/image yet of a terminal with content to identify
"yeah,
see they are using a S/370 there" (maybe its
listing disk packs,
tapes, memory resources, etc?) I got something like this for the
earlier CTSS and TOPS-10.
pass me what you have for that so I can see what a VM Equivalent
might
be. The definitive thing on a users 3270 is the status bottom right
which on a pukka system which usually reads "VM READ VM/370" but can
also start "RUNNING", "HOLDING" "CP READ".
-Steve
Dave
12:25 p.m.
On 2/7/2026 1:44 PM, Carey Schug via cctalk wrote:
the 1401 (1410/1440/7010/etc) emulators were
microcode. an extra cost for
the microcode and probably another extra cost for the read only storage for
the extra microcode.
That is *partly* correct. I haven't looked at them all, but the 1410
was microcode *ASSIST* not pure microcode - and the 7010 would be the
same. I have seen the code for the 1410 emulator. I expect the 1401
and 1440 would be similar.
(UNIVAC actually had a customer written 1410 emulator too - I have the
flowcharts for that one.)
Initially, on the 360s, you could push buttons on the
console, and have one
or more 14xx series machines if you had enough memory. perhaps with 370s
too.
Don't know about that one way or the other - if there were a button, I
suppose it would have been an IML button of some sort to load the
microcode assist.
then you could IPL a card deck with a minimal 360 in-memory operating
system, and run one or more 14xx series machines with console commands (I
think, I never did this)
'
Basically correct - the emulators ran as application programs, as far as
I know. (At most, a 1410 would use 100K bytes, so how much you had left
would depend on whether you used up 40, 60, 80 or 100K for the 1410/7010 .)
THen you could run a program in one of the dos
partitions (BG,F1.F2) that
would dynamically start a 1401 job by reading in the 14xx program from
cards, while running a native 360 program in the other partition, all as
batch jobs scheduled by reading them into the card reader There was also
1620 emulation and maybe others.,
Basically correct - the emulators ran as application programs, as far as
I know.
By the time my employer got to 370 I think they had
gotten rid of the 14xx
emulation, but they were availble.
JRJ
12:57 p.m.
My Dad was a 360 operator, as was I. I will swear he set the load unit as 00C and hit
load. In the card reader was something labeled CID. Compatibility Initialization Deck. Was
less than 1/2 inch of cards. I believe it put the Mod 30 (or 40) into pure 1401 mode. No
360 code running.
8 Feb
8 Feb
7:19 a.m.
On Feb 7, 2026, at 3:57 PM, Donald Whittemore via
cctalk <cctalk(a)classiccmp.org> wrote:
My Dad was a 360 operator, as was I. I will swear he set the load unit as 00C and hit
load. In the card reader was something labeled CID. Compatibility Initialization Deck. Was
less than 1/2 inch of cards. I believe it put the Mod 30 (or 40) into pure 1401 mode. No
360 code running.
You can certainly IPL off the card reader, though I've never done it. I did see the
360 model 44 "emulator" deck, which is loaded that way using the "Emulator
IPL" button, into a separate block of memory invisible during normal execution.
It's vaguely like Alpha PALcode, I guess.
That deck was a standard IBM 360 object program file, with the channel program on the
first card loading all the pieces to the right places.
No idea what this CID was. It could be simply a "bare metal" ordinary 360
program, or a 360 program combined with helper microcode.
paul
7 Feb
7 Feb
1:34 p.m.
On Sat, 2026-02-07 at 14:25 -0600, Jay Jaeger via cctalk wrote:
On a 360/30 with 1401 microcode that I used in 1967, one would first
load the small "Compatible Initialization Deck" (about fifty cards).
Then set the microcode address to 1402 (1401?) to load from cards, of
1729 (I'm confident I remember this correctly) to load from tape, then
push the IPL button. I don't remember what microcode addresses one
would use to run it as a 360 because the only 360 program I ever used
was SORT --- which was much faster than 1401 SORT 7 because the 240x
tape drives could (and did) do read reverse — but I ran 360 SORT only
once or twice.
The 360/30 was a temporary stopgap because the company was converting
all its Autocoder programs to COBOL in anticipation of replacing the
1401s with Burroughs 2500s, not 360s. So I mostly did 1401 COBOL
compiles followed by Autocoder assemblies. They didn't use 360 COBOL
because some processing centers still had real 1401s. They'd already
tried Honeywell 200s using using Liberator and Easycoder and weren't
satisfied. The processor was OK but the unit-record peripherals,
especially the drum printer, were crap.
Initially, on
the 360s, you could push buttons on the console, and
have one
or more 14xx series machines if you had enough memory. perhaps
with 370s
too.
Don't know about that one way or the other - if there were a button,
I
suppose it would have been an IML button of some sort to load the
microcode assist.
11:08 a.m.
Steve,
If you mean something like these pics :-
https://github.com/g4ugm/vm370.source
which are screen grabs from a terminal emulator connected to the final
release on VM/370 running on the Hercules emulator so the content is
true to life.
If you like them I'll fire up a green screen terminal and take some
photos of the screen
Dave
On 07/02/2026 03:51, Steve Lewis via cctalk wrote:
Dave,
Page 439 of that document you linked has a nice chart of "integrated
emulators that run execute under VM/370" - now I do recall one of the
"famous" things about the prior S/360 was it could emulate 1401 and other
IBM systems. Then later on, more systems to emulate would be the
709-series. Ok, so VM/370 is more like what we might today call a
Hypervisor? So the "it looks like whatever you want" comment makes
sense.
I suppose what I'm after is more a visual on the usage of CMS, DOS/VS or
OS/VS1 ( OS's that one would only use on an S/370 ? )
I put a couple reference images here on what I have about CTSS and TOPS-10
(CTSS is from a modern-day emulators, TOPS-10 is from one of their manuals
so its from in 1970). I see how you mean VM/370 isn't quite the same
nature (not "just an OS" but an enterprise thing like for airlines, banks,
financial brokers -- and the virtualization helped in testing/deploying new
systems -- that maybe had newer OS's -- without disrupting operational
systems?)
https://github.com/voidstar78/OS_NOTES
- Steve
On Fri, Feb 6, 2026 at 10:00 AM David Wade <dave.g4ugm(a)gmail.com> wrote:
>
> On 06/02/2026 14:55, Steve Lewis wrote:
>> Thanks Dave, the 3270 terminal screen makes sense. Or to make use of
>> the system and resources, you'd remote to it using a 3270.
>> So it may have been at a time no one thought to snap a photograph of
>> any of those 3270s in use (not just a "room full of 3270's" kind of
>> photo - but of the actual screen, showing whatever it was they were
>> doing; managing tape/disk resources, files, users, or running APL or
>> something. That's more what I was looking for, when you "used VM/370
>> {or remoted into it}, this is what it looked like."
> Generally thats not what you did with VM/370. You edited, compiled, and
> ran programs....
>
>> There had to be some kind of installer? Or maybe I'm viewing it wrong
>> - they (a business) didn't just buy a S/370 then decide what OS to
>> install. But rather it was a packaged prepared by IBM, so maybe it
>> was pre-installed with VM/370 and configured to whatever the
>> arrangement/contract was?
> For VM you usually got a "starter system" on a tape. There was a
> different tape for each disk type. The first file on the tape is the
> standalone disk dump and restore program, DDR. So you IPL (boot) from
> this tape, and use DDR to restore the starter system to DASD (disk).
> You usually needed three packs. The first time you IPL the restored
> starter system it asks you some basic config questions, and you then
> have a working system that you can use to restore the rest of the
> VM/370, load and apply service (fixes) , and configure to your exact
> hardware set-up.
>
> I expect at 522 pages this manual which covers install and congigureis a
> tad bigger than the one for other systems...
>
>
>
https://bitsavers.org/pdf/ibm/370/VM/370/Release_6/GC20-1801-10_VM370_Sysge…
>
>
>> Or a way to say "when someone used a S/370 {or CMS}, this is what the
>> console content looked like" (printed, or by that time yea probably
>> more likely a CRT).
>>
> It looked like whatever you wanted. The samples in the previous e-mail
> are typical...
>
>
>> “The Origin of the VM/370 Time-Sharing System” – R.J. Creasy gives a
>> little bit of a description on those components CP, CMS, and RSCS.
>> But no photo/image yet of a terminal with content to identify "yeah,
>> see they are using a S/370 there" (maybe its listing disk packs,
>> tapes, memory resources, etc?) I got something like this for the
>> earlier CTSS and TOPS-10.
>>
> pass me what you have for that so I can see what a VM Equivalent might
> be. The definitive thing on a users 3270 is the status bottom right
> which on a pukka system which usually reads "VM READ VM/370" but can
> also start "RUNNING", "HOLDING" "CP READ".
>
>> -Steve
>>
>>
> Dave
>
12:23 p.m.
David,
Yes that SCREEN2 image is pretty good, since it shows the CMS version and
year (1985). An earlier version would be nice, but if that 6.0 stuff is
still representative of what the earlier versions would show, that's fine.
Actual contemporary (1970s) photos of screens are, I imagine, hard to find
-- anyone taking a Kodak into a server room and getting close up of screens
were likely to be arrested for espionage, then hung. Times were different
back then!
Mostly this is for a talk in May about multitasking operating systems -
time-share existed throughout all of the 1960s, basically becoming an
expected aspect/feature of a computer. Thus this is why it was somewhat
laughable to call the early microcomputers as computers - this isn't to
belittle the talent on creating home personal computers, but more the
"initial public reaction" in early 1970s of going around saying "I'm
selling a computer" (it would be almost viewed as false advertisement and
you'd get punched in the nose). A "computer" then was some big massive
leased equipment. So the early micro-computer pioneers couldn't call it a
computer (used terms "intelligent terminal" and such instead), but to be
fair they couldn't do time-share either, just not capable enough yet (they
were essentially desktop calculators, with a bit of memory). Micros didn't
get hardware-accelerated (MMU) multitasking till mid-1980s, thus finally
catching up to the time-share systems of two decades prior.
Photos of teletype output of those early operating systems would be nice to
find (pre-CRT era), there is one nice contemporary video on CTSS being used
in operation (computer room was so loud, they had to go to a different room
with the teletype).
-Steve
On Sat, Feb 7, 2026 at 1:08 PM David Wade via cctalk <cctalk(a)classiccmp.org>
wrote:
Steve,
If you mean something like these pics :-
https://github.com/g4ugm/vm370.source
which are screen grabs from a terminal emulator connected to the final
release on VM/370 running on the Hercules emulator so the content is
true to life.
If you like them I'll fire up a green screen terminal and take some
photos of the screen
Dave
On 07/02/2026 03:51, Steve Lewis via cctalk wrote:
Dave,
Page 439 of that document you linked has a nice chart of "integrated
emulators that run execute under VM/370" - now I do recall one of the
"famous" things about the prior S/360 was it could emulate 1401 and other
IBM systems. Then later on, more systems to emulate would be the
709-series. Ok, so VM/370 is more like what we might today call a
Hypervisor? So the "it looks like whatever you want" comment makes
sense.
I suppose what I'm after is more a visual on the usage of CMS, DOS/VS or
OS/VS1 ( OS's that one would only use on an S/370 ? )
I put a couple reference images here on what I have about CTSS and
TOPS-10
(CTSS is from a modern-day emulators, TOPS-10 is
from one of their
manuals
so its from in 1970). I see how you mean VM/370
isn't quite the same
nature (not "just an OS" but an enterprise thing like for airlines,
banks,
financial brokers -- and the virtualization
helped in testing/deploying
new
systems -- that maybe had newer OS's --
without disrupting operational
systems?)
https://github.com/voidstar78/OS_NOTES
- Steve
On Fri, Feb 6, 2026 at 10:00 AM David Wade <dave.g4ugm(a)gmail.com> wrote:
>
> On 06/02/2026 14:55, Steve Lewis wrote:
>> Thanks Dave, the 3270 terminal screen makes sense. Or to make use of
>> the system and resources, you'd remote to it using a 3270.
>> So it may have been at a time no one thought to snap a photograph of
>> any of those 3270s in use (not just a "room full of 3270's" kind of
>> photo - but of the actual screen, showing whatever it was they were
>> doing; managing tape/disk resources, files, users, or running APL or
>> something. That's more what I was looking for, when you "used VM/370
>> {or remoted into it}, this is what it looked like."
> Generally thats not what you did with VM/370. You edited, compiled, and
> ran programs....
>
>> There had to be some kind of installer? Or maybe I'm viewing it wrong
>> - they (a business) didn't just buy a S/370 then decide what OS to
>> install. But rather it was a packaged prepared by IBM, so maybe it
>> was pre-installed with VM/370 and configured to whatever the
>> arrangement/contract was?
> For VM you usually got a "starter system" on a tape. There was a
> different tape for each disk type. The first file on the tape is the
> standalone disk dump and restore program, DDR. So you IPL (boot) from
> this tape, and use DDR to restore the starter system to DASD (disk).
> You usually needed three packs. The first time you IPL the restored
> starter system it asks you some basic config questions, and you then
> have a working system that you can use to restore the rest of the
> VM/370, load and apply service (fixes) , and configure to your exact
> hardware set-up.
>
> I expect at 522 pages this manual which covers install and congigureis a
> tad bigger than the one for other systems...
>
>
>
https://bitsavers.org/pdf/ibm/370/VM/370/Release_6/GC20-1801-10_VM370_Sysge…
>
>
>> Or a way to say "when someone used a S/370 {or CMS}, this is what the
>> console content looked like" (printed, or by that time yea probably
>> more likely a CRT).
>>
> It looked like whatever you wanted. The samples in the previous e-mail
> are typical...
>
>
>> “The Origin of the VM/370 Time-Sharing System” – R.J. Creasy gives a
>> little bit of a description on those components CP, CMS, and RSCS.
>> But no photo/image yet of a terminal with content to identify "yeah,
>> see they are using a S/370 there" (maybe its listing disk packs,
>> tapes, memory resources, etc?) I got something like this for the
>> earlier CTSS and TOPS-10.
>>
> pass me what you have for that so I can see what a VM Equivalent might
> be. The definitive thing on a users 3270 is the status bottom right
> which on a pukka system which usually reads "VM READ VM/370" but can
> also start "RUNNING", "HOLDING" "CP READ".
>
>> -Steve
>>
>>
> Dave
>
3:28 p.m.
On 07/02/2026 20:23, Steve Lewis via cctalk wrote:
David,
Yes that SCREEN2 image is pretty good, since it shows the CMS version and
year (1985). An earlier version would be nice, but if that 6.0 stuff is
still representative of what the earlier versions would show, that's fine.
Pretty much. There is a PDF of a VM/370 Release 1 Terminal Users Guide..
https://www.ibm.com/support/pages/zvm/history/50th/vm370ref.pdf
and you can see all the commands in there are the same as on the later
systems.
I think at that time there might have been more 2741 golf ball terminals
than screens.
There were also possibly some 2260 screens....
https://en.wikipedia.org/wiki/IBM_2260
.. I used a 2260 at Newcastle upon Tyne University in 1972 but on MTS
not on VM/CMS...
Actual contemporary (1970s) photos of screens are, I
imagine, hard to find
-- anyone taking a Kodak into a server room and getting close up of screens
were likely to be arrested for espionage, then hung. Times were different
back then!
Actually a Kodak wasn't much use. Taking pictures of screens is hard. At
one place we had a hooded Polaroid with a hood ..
https://www.ebay.co.uk/itm/271351649382
Mostly this is for a talk in May about multitasking
operating systems -
time-share existed throughout all of the 1960s, basically becoming an
expected aspect/feature of a computer.
If you are interested in 1960's then perhaps look at MTS and Music as
well...
Thus this is why it was somewhat
laughable to call the early microcomputers as computers - this isn't to
belittle the talent on creating home personal computers, but more the
"initial public reaction" in early 1970s of going around saying "I'm
selling a computer" (it would be almost viewed as false advertisement and
you'd get punched in the nose). A "computer" then was some big massive
leased equipment. So the early micro-computer pioneers couldn't call it a
computer (used terms "intelligent terminal" and such instead), but to be
fair they couldn't do time-share either, just not capable enough yet (they
were essentially desktop calculators, with a bit of memory). Micros didn't
get hardware-accelerated (MMU) multitasking till mid-1980s, thus finally
catching up to the time-share systems of two decades prior.
oh I don't know. You don't need memory management on a single user system.
..
Photos of teletype output of those early operating
systems would be nice to
find (pre-CRT era), there is one nice contemporary video on CTSS being used
in operation (computer room was so loud, they had to go to a different room
with the teletype).
Lawrence Wilkinson has an FPGA implementation of an IBM S/360 model 30
https://www.ljw.me.uk/ibm360/
and there is a video of it printing an assembler listing on a IBM IO
Selectric
https://www.youtube.com/watch?v=r67StSAmEjk
I think that is about as close as you can get to a real 360 at present...
Dave
-Steve
On Sat, Feb 7, 2026 at 1:08 PM David Wade via cctalk<cctalk(a)classiccmp.org>
wrote:
> Steve,
> If you mean something like these pics :-
>
> https://github.com/g4ugm/vm370.source
>
> which are screen grabs from a terminal emulator connected to the final
> release on VM/370 running on the Hercules emulator so the content is
> true to life.
> If you like them I'll fire up a green screen terminal and take some
> photos of the screen
>
> Dave
>
> On 07/02/2026 03:51, Steve Lewis via cctalk wrote:
>> Dave,
>>
>> Page 439 of that document you linked has a nice chart of "integrated
>> emulators that run execute under VM/370" - now I do recall one of the
>> "famous" things about the prior S/360 was it could emulate 1401 and
other
>> IBM systems. Then later on, more systems to emulate would be the
>> 709-series. Ok, so VM/370 is more like what we might today call a
>> Hypervisor? So the "it looks like whatever you want" comment makes
>> sense.
>>
>> I suppose what I'm after is more a visual on the usage of CMS, DOS/VS or
>> OS/VS1 ( OS's that one would only use on an S/370 ? )
>>
>> I put a couple reference images here on what I have about CTSS and
> TOPS-10
>> (CTSS is from a modern-day emulators, TOPS-10 is from one of their
> manuals
>> so its from in 1970). I see how you mean VM/370 isn't quite the same
>> nature (not "just an OS" but an enterprise thing like for airlines,
> banks,
>> financial brokers -- and the virtualization helped in testing/deploying
> new
>> systems -- that maybe had newer OS's -- without disrupting operational
>> systems?)
>>
>> https://github.com/voidstar78/OS_NOTES
>>
>>
>> - Steve
>>
>>
>>
>>
>> On Fri, Feb 6, 2026 at 10:00 AM David Wade<dave.g4ugm(a)gmail.com> wrote:
>>
>>> On 06/02/2026 14:55, Steve Lewis wrote:
>>>> Thanks Dave, the 3270 terminal screen makes sense. Or to make use of
>>>> the system and resources, you'd remote to it using a 3270.
>>>> So it may have been at a time no one thought to snap a photograph of
>>>> any of those 3270s in use (not just a "room full of 3270's"
kind of
>>>> photo - but of the actual screen, showing whatever it was they were
>>>> doing; managing tape/disk resources, files, users, or running APL or
>>>> something. That's more what I was looking for, when you "used
VM/370
>>>> {or remoted into it}, this is what it looked like."
>>> Generally thats not what you did with VM/370. You edited, compiled, and
>>> ran programs....
>>>
>>>> There had to be some kind of installer? Or maybe I'm viewing it
wrong
>>>> - they (a business) didn't just buy a S/370 then decide what OS to
>>>> install. But rather it was a packaged prepared by IBM, so maybe it
>>>> was pre-installed with VM/370 and configured to whatever the
>>>> arrangement/contract was?
>>> For VM you usually got a "starter system" on a tape. There was a
>>> different tape for each disk type. The first file on the tape is the
>>> standalone disk dump and restore program, DDR. So you IPL (boot) from
>>> this tape, and use DDR to restore the starter system to DASD (disk).
>>> You usually needed three packs. The first time you IPL the restored
>>> starter system it asks you some basic config questions, and you then
>>> have a working system that you can use to restore the rest of the
>>> VM/370, load and apply service (fixes) , and configure to your exact
>>> hardware set-up.
>>>
>>> I expect at 522 pages this manual which covers install and congigureis a
>>> tad bigger than the one for other systems...
>>>
>>>
>>>
>
https://bitsavers.org/pdf/ibm/370/VM/370/Release_6/GC20-1801-10_VM370_Sysge…
>>>
>>>> Or a way to say "when someone used a S/370 {or CMS}, this is what
the
>>>> console content looked like" (printed, or by that time yea probably
>>>> more likely a CRT).
>>>>
>>> It looked like whatever you wanted. The samples in the previous e-mail
>>> are typical...
>>>
>>>
>>>> “The Origin of the VM/370 Time-Sharing System” – R.J. Creasy gives a
>>>> little bit of a description on those components CP, CMS, and RSCS.
>>>> But no photo/image yet of a terminal with content to identify "yeah,
>>>> see they are using a S/370 there" (maybe its listing disk packs,
>>>> tapes, memory resources, etc?) I got something like this for the
>>>> earlier CTSS and TOPS-10.
>>>>
>>> pass me what you have for that so I can see what a VM Equivalent might
>>> be. The definitive thing on a users 3270 is the status bottom right
>>> which on a pukka system which usually reads "VM READ VM/370" but
can
>>> also start "RUNNING", "HOLDING" "CP READ".
>>>
>>>> -Steve
>>>>
>>>>
>>> Dave
>>>
>
6 Feb
6 Feb
8:30 a.m.
Maybe of use with current usage and foundational concepts:
https://interskill.com/course/z-vm-introduction-and-concepts-z-vm-7-4/
Don't know if Lynn Wheeler is on this list, but he is active on Facebook
and Linkedin and knows a lot about early VM.
HTH!
Lee Courtney
On Fri, Feb 6, 2026 at 12:31 AM Steve Lewis via cctalk <
cctalk(a)classiccmp.org> wrote:
Hey all,
I was trying to track down some kind of image/photo of "what IBM VM/370
looks like" (the operating system)
I tried looking also in the IBM manuals - I'm just not finding much. Some
kind of image of what maybe a remote login looked like, a task process
list, or maybe basic file/folder management commands, or how an editor or
programming worked on that system.
There is a bit of media with a VM/370 emulator, but I wasn't sure how
accurately representative it was of a kind of "look and feel" of that OS.
What I'd need is maybe photographs of teletype printouts? This was still
early 1970s. Which is understandable not much of that was probably kept
around.
Thanks, just digging around - like wasn't sure if VM/370 was still
six-character filename limited like earlier 60s era OS's, or whatever
characteristics it had in operating it.
-Steve
--
Lee Courtney
+1-650-704-3934 cell
1
days inactive
3
days old
22 comments
13 participants
participants (13)
-
Carey Schug -
David Wade -
David Wade -
Donald Whittemore -
Jay Jaeger -
Jim Davis -
Lee Courtney -
Lyndon Nerenberg (VE7TFX/VE6BBM) -
Paul Koning -
r.stricklin -
Steve Lewis -
Van Snyder -
Wayne S