DU
Subject: Re: [IBM-MAIN] [External] Re: Ancient DASD connectivity
W dniu 2019-05-17 o 14:47, Ron Hawkins pisze:
> Rex,
>
> I cannot find Alan's quoted passage, but I think it is a stretch to say "
> With the arrival of 2105s, the CU was inside the same cabinet as the
W dniu 2019-05-17 o 14:47, Ron Hawkins pisze:
Rex,
I cannot find Alan's quoted passage, but I think it is a stretch to say " With the
arrival of 2105s, the CU was inside the same cabinet as the drives and Logical CUs (LCUs)
were born."
I'm fairly certain that EMC, STK, and HDS delivering this
f Joe
Monk
Sent: Saturday, May 18, 2019 6:45 AM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: Ancient DASD connectivity
The 3375 (CKD brother of the 3370 FBA) was attached thru a 3880 storage
control. There were A,B, and D units. The D units were the tails and the A
units were the heads. The D
metz3
> >
> >
> > From: IBM Mainframe Discussion List on behalf
> > of Martin Packer
> > Sent: Friday, May 17, 2019 10:33 AM
> > To: IBM-MAIN@LISTSERV.UA.EDU
> > Subject: Re: Ancient DASD connectivity
> >
> >
;
> --
> Shmuel (Seymour J.) Metz
> http://mason.gmu.edu/~smetz3
>
>
> From: IBM Mainframe Discussion List on behalf
> of Martin Packer
> Sent: Friday, May 17, 2019 10:33 AM
> To: IBM-MAIN@LISTSERV.UA.EDU
> Subject: Re: Ancient DAS
behalf of
Martin Packer
Sent: Friday, May 17, 2019 10:33 AM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: Ancient DASD connectivity
And then there were double-ended strings of disks. 3350s? Just before my
time, really.
Martin Packer
zChampion, Systems Investigator & Performance Troubleshooter, IBM
ur J Metz
To: IBM-MAIN@LISTSERV.UA.EDU
Date: 17/05/2019 15:18
Subject: Re: Ancient DASD connectivity
Sent by:IBM Mainframe Discussion List
T A unit attached to a CU; it was the CU that attached directly to the
channel. There is some overloaded nomenclature here; the con
From: IBM Mainframe Discussion List on behalf of
Alan Altmark
Sent: Friday, May 17, 2019 10:02 AM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: Ancient DASD connectivity
On Thu, 16 May 2019 15:26:45 +, Seymour J Metz wrote:
>Well, for some devices the CU and device were in the same
On Thu, 16 May 2019 15:26:45 +, Seymour J Metz wrote:
>Well, for some devices the CU and device were in the same box, e.g., 2501.
Yes. A-units (Axx models) often include(d) at least one, possibly two or even
four, I/O devices, with B units (Bxx models) providing expansion. Last CU
standin
r, Rex
Sent: Thursday, 16 May 2019 05:53
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: [IBM-MAIN] [External] Re: Ancient DASD connectivity
It was sheer size of the componentry that drove this design. I think the 3990
was the last stand-alone disk controller. With the arrival of 2105s, the CU
was i
@LISTSERV.UA.EDU
Subject: Re: [External] Re: Ancient DASD connectivity
On Thu, 16 May 2019 at 12:50, Alan Altmark wrote:
> Disk, tape, and unit record devices of the same era had discrete
> controllers. Unit record CU (2821) was interesting in that it talked to
> devices that did different thi
On Thu, 16 May 2019 at 12:50, Alan Altmark wrote:
> Disk, tape, and unit record devices of the same era had discrete
> controllers. Unit record CU (2821) was interesting in that it talked to
> devices that did different things: 1403/1404 printer and 2540 card
> reader-punch. Clever of them.
>
019 12:50 PM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: [External] Re: Ancient DASD connectivity
On Wed, 15 May 2019 18:12:19 -0500, Tom Marchant
wrote:
>The s/360 POO (available on bitsavers), says,
>"A control unit may be housed separately or it may be physically
>and logically in
On Wed, 15 May 2019 18:12:19 -0500, Tom Marchant
wrote:
>The s/360 POO (available on bitsavers), says,
>"A control unit may be housed separately or it may be physically
>and logically integral with the I/O device."
The classic example of early CU integration was the 2701 communications
contro
@LISTSERV.UA.EDU
Subject: Re: Ancient DASD connectivity
On Wed, 15 May 2019 21:41:20 +, Seymour J Metz wrote:
>That may be true for 2314, but it is not true for anything later. The A unit
>connects to the control unit, not to the channel.
>
I actually intended to say that the A units con
DWIN was superesed by DWIM - Do what I meant!
-Original Message-
From: IBM Mainframe Discussion List On Behalf Of
John McKown
Sent: Thursday, May 16, 2019 9:53 AM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: [External] Re: Ancient DASD connectivity
On Thu, May 16, 2019 at 8:08 AM Pommier
ction.
Because end users don't really know what they need and their "wants" are
not always helpful.
>
> Rex
>
> -Original Message-
> From: IBM Mainframe Discussion List On Behalf
> Of Tom Marchant
> Sent: Wednesday, May 15, 2019 6:12 PM
> To
PM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: [External] Re: Ancient DASD connectivity
On Wed, 15 May 2019 20:31:55 +, Pommier, Rex wrote:
>The point I was making was that IBM had some DASD subsystems for
>large(r) customers with integrated controllers
Oh. Sorry I misunderstood. Thanks for the clar
W dniu 2019-05-15 o 21:53, Pommier, Rex pisze:
It was sheer size of the componentry that drove this design. I think the 3990
was the last stand-alone disk controller. With the arrival of 2105s, the CU
was inside the same cabinet as the drives and Logical CUs (LCUs) were born.
One big blac
On Wed, 15 May 2019 20:31:55 +, Pommier, Rex wrote:
>The point I was making was that IBM had some DASD subsystems for large(r)
>customers with integrated controllers
Oh. Sorry I misunderstood. Thanks for the clarification.
The s/360 POO (available on bitsavers), says,
"A control unit may b
On Wed, 15 May 2019 21:41:20 +, Seymour J Metz wrote:
>That may be true for 2314, but it is not true for anything later. The A unit
>connects to the control unit, not to the channel.
>
I actually intended to say that the A units connected to the control unit. I
don't know why I said "chan
: Wednesday, May 15, 2019 2:39 PM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: Ancient DASD connectivity
On Wed, 15 May 2019 14:59:00 +0200, R.S. wrote:
>In the old days there was a Storage Control Unit, i.e. 3830 and disk
>controller within disk cabinet, i.e. 3350-A2
>
>So, we have CPC
DASD footprint compared
to the 3880/3380s they replaced. :-)
Rex
-Original Message-
From: IBM Mainframe Discussion List On Behalf Of Tom
Marchant
Sent: Wednesday, May 15, 2019 3:09 PM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: [External] Re: Ancient DASD connectivity
On Wed, 15 May 2019
On Wed, 15 May 2019 19:53:07 +, Pommier, Rex wrote:
>where did the 9340 subsystem fit in the timeline between 3990 and 2105? or the
>RAMAC2?
https://en.wikipedia.org/wiki/History_of_IBM_magnetic_disk_drives#IBM_9340_and_9345
--
Tom Marchant
---
Rex
-Original Message-
From: IBM Mainframe Discussion List On Behalf Of
Alan Altmark
Sent: Wednesday, May 15, 2019 1:39 PM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: [External] Re: Ancient DASD connectivity
On Wed, 15 May 2019 14:59:00 +0200, R.S. wrote:
>In the old days there was a
On Wed, 15 May 2019 14:59:00 +0200, R.S. wrote:
>In the old days there was a Storage Control Unit, i.e. 3830 and disk
>controller within disk cabinet, i.e. 3350-A2
>
>So, we have CPC-cable1-3830-cable2-3350A2controller-internal_cable3-disk.
>
>I'm trying to understand separation of duties between
The first question is how old.
In general, a channel connects to a control unit, which either connects to an
I/O device or which also serves the role of an I/O device. A complication is
that some processors had an option for an integrated adapter that served the
role of both controller and devi
___
From: IBM Mainframe Discussion List on behalf of
Allan Staller
Sent: Wednesday, May 15, 2019 9:58 AM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: Ancient DASD connectivity
The first device to support "disconnect" was the 3330 which also connected to a
3830.
Prior to that IO in both direct
The first device to support "disconnect" was the 3330 which also connected to a
3830.
Prior to that IO in both directions tied up the entire path from CPU to device
and back for the duration (2314, 2311 dasd).
The flow of a "typical" IO request:
Channel passes commands to 3830 and disconnects.
3
On Wed, 15 May 2019 14:59:00 +0200, R.S. wrote:
>(this is mostly historical question)
It might be helpful to you to get a copy of the System/360 Principles
of Operation, which describes this a little bit. You can find it on bitsavers.
http://bitsavers.trailing-edge.com/pdf/ibm/360/princOps/A22-6
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