Tony, I wished for the book you wanted in the original post many times
and never found it. I wound up cobbling together a bunch of sources. The
PoP was essential for the basics of the channel subsystem, but you have
to go to the various device manuals for anything specific to them.
For ECKD, the only authoritative references I found were the storage
controller (what we used to call the control unit) references. I started
with the 3990 Storage Control Reference, which IIRC was strangely hard
to find as a PDF - I had a tattered hardcopy I kept locked away in my
office for years. Later I used the IBM Enterprise Storage Server
System/390 Command Reference 2105 Models E10, E20, F10, and F20
(SC26-7298) - newer, though it's old now too, and it was available in
PDF. Some of the equivalent manuals for other brands of ECKD storage
subsystems also have good information but as usual be very careful about
applying it beyond the hardware for which it was written.
Those are good for technical details of the various CCWs, error
conditions, and sense information, but they had no practical examples. I
was fortunate to always have VM systems available, and I shamelessly
scrounged through the optional source code to see how the IBM developers
coded their channel programs, and learned a lot. I also found some
interesting channel programs in the sources for the Linux z distros -
not all of the device specific stuff is closed source. The Hercules
project also has some good stuff online.
I wrote a lot of channel programs that ran on z/OS or its precursors,
but even allowing for my VM bias I believe it's a lot easier to learn
this stuff, and debug when you're doing something new, by experimenting
on VM. You're a lot closer to the action, the CP diagnose interface
allows you to execute channel programs synchronously with CP handling
the interrupts and gathering sense info for you, the CP tracing
facilities are very powerful and helpful, and CP provides extremely
strong isolation that kept me from ever shooting anyone's feet but my
own. Saved me huge amounts of time.
Good luck!
Steve
On 7/19/2024 12:45 PM, Tony Thigpen wrote:
SA22-1025-00
Internal Disk Subsystem:
Reference Guide
Multiprise 3000 Enterprise Server
Tony Thigpen
Michael Watkins wrote on 7/19/24 1:29 PM:
What is the full title of the 'MP3k' book? Is it an IBM document?
-----Original Message-----
From: IBM Mainframe Assembler List <[email protected]>
On Behalf Of Tony Thigpen
Sent: Thursday, July 18, 2024 5:57 PM
To: [email protected]
Subject: Re: Looking for a good book on ECKD EXCP, CCWs, etc.
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Thanks Ed. I do have that book. It's actually better indexed than the
other book I was using as a reference even though the MP3K book was
dated a few months earlier.
Tony Thigpen
Ed Jaffe wrote on 7/18/24 5:46 PM:
The reference I learned from was the MP3000 book describing the CCWs
available on its integrated SSD RAID DASD.
On 7/18/2024 1:13 PM, Tony Thigpen wrote:
I have several books that include basic EXCP/CCW dasd programming,
but nothing that I would consider 'deep' enough on ECKD programming.
Some of the books I have are were good with CKD, but not ECKD.
So, I am looking for suggestions for books that are designed to teach
someone complex ECKD programming within the restrictions imposed by
the OS.
Tony Thigpen
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