I think I understand your confusion. I'm not sure why you're using the
z/OS V1.10 level of the book. But in any event, the current (V2.2)
level of the book says this returns, for INFO=DASD:
Returns 16 bytes as follows:
Bytes 0-3 - Number of cylinders on the device, excluding alternates. <snip>
Bytes 4-7 - Number of tracks per cylinder.
So one would reasonably expect x'FFF00000' to be the number of
cylinders, and x'000FF000' to be the number of tracks per cylinder. The
values of the first halfwords in each word, however, seem far more
reasonable (possible, even!). The correct number of tracks/cylinder is
definitely 15.
But what is the actual size of the volume? You can use "V" on ISPF
OPT3.4 to see VTOC information, including the volume size in tracks
under "Volume data" on the left. Divide by 15 to get cylinders. What
do you see?
It's likely RCF time...
Reichman Joseph wrote:
7.2.15 Marked DEVTYPE- info form from DFSMSdfp "Advanced Services" z/os
V1R10.0
Joe Reichman
Joe Reichman
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-----Original Message-----
From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf
Of Elardus Engelbrecht
Sent: Thursday, July 21, 2016 12:52 PM
To: [email protected]
Subject: Re: DEVTYPE INFO=DASD
Reichman Joseph wrote:
The doc says bytes 0 - 3 is cylinders bytes 0 -3 is FFF00000 and bytes 4 - 7
000FF000 is tracks per cyl ? am I misreading misunderstanding the documentation
What docs? Could you be kind to give us the URL of that source of above info
and docs?
I was looking for the capability on a dasd device DEVTYPE
(R6),(AREA,L'AREA),INFOLIST=ILIST2
ILIST2 DEVTYPE INFO=DASD
AREA DS XL16
Hmmm, interesting application of that useful macro. I must try out this little
gem next week on my z/OS v2.1 sandbox when I'm returning to my bread and butter
work... ;-)
This was the data returned in area R15 = 0
FFF00000 000FF000 00000100 08000000
On what z/OS level were you trying to try out that Assembler snippet? How did
you obtained the contents of that R15? Via a dump or a MVC or something else?
Mike Schwab wrote:
FFF00000 000FF000 00000100 08000000
x'FFF0' would be 65520 cylinders. x'000F' would be 15 tracks per cylinder.
Reasonable for a 3390-54.
<snip>
--
John Eells
IBM Poughkeepsie
[email protected]
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