2008/6/2 Eric Chevalier <[EMAIL PROTECTED]>: > However, we were using 2314s attached to these boxes, and I believe > there _was_ a hardware RPQ on the drives. Called something like > "Airlines Control Buffer", I _think_ the feature allowed the drive to > disconnect from the channel while doing a seek. Whatever the details, > it was something that became standard on later mainframe drives from > IBM.
I never saw one, but I do remember coming across the description. I remember it a bit differently; I understood it was a feature (RPQ) on the controller that allowed the search (not seek) to be offloaded to the controller, so as not to tie up the (selector) channel during the Search/TIC loop. I suppose this sounds like a precursor to RPS on the 3330, but RPS doesn't search the actual records; it disconnects from the (BMX) channel until a previously set sector is about to come around under the head, and then attempts to reconnect so the channel can do the Search/TIC loop with minimal delay. But as you said: > OK, it's been almost thirty years, so my memory may be a bit hazy... Tony H. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
