No, Seek and Set Sector are unrelated. Typically the Seek would be the first CCW after the Reserve, if any; Set Sector would normally be just prior to a Search. Both attempt to disconnect after data transfer.
-- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Discussion List <IBM-MAIN@listserv.ua.edu> on behalf of Ron hawkins <ronjhawk...@sbcglobal.net> Sent: Wednesday, January 24, 2018 5:59 PM To: IBM-MAIN@listserv.ua.edu Subject: Re: CKD details Tony, I am way in over my head here, and I am sure I will use the wrong terminology. As I remember it RPS was implemented by passing seek and set sector to the DASD together so there was only one disconnect sequence? Without RPS there was a disconnect/reconnect sequence for the seek, followed by set sector. Or something like that. My curiosity is crying out for someone to correct me 😊 Ron -----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Tony Harminc Sent: Wednesday, January 24, 2018 10:29 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: [IBM-MAIN] CKD details On 24 January 2018 at 10:57, Seymour J Metz <sme...@gmu.edu> wrote: I wrote: >> What use is Set Sector without a block multiplexor channel (which >> allows disconnect/reconnect)? Were those available for some S/360 >> models? > Of course they were available; the model number for the 230 should be a clue > that it was announced for the S/360. For that matter, the model number of > the 2880 is a dead giveaway. Check bitsavers for the 360/85 and 360/195. I understand the model numbering. But there's no *requirement* to use Set/Read Sector in your channel programing for a device that supports RPS; it's just a performance issue. A 3330 (and a fortiori, a 2305) should be able to be plugged into a 2860 selector channel and still work. Tony H. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
