[EMAIL PROTECTED] (R.S.) writes: > ESCON: > MM - 3km > SM - 20km > Typical value in sales leaflets is 43km which means XDF feature > (means Single Mode) in CPC - 20km - Escon Director - 20km -Escon > Director - 3km. The last distance had to be 3km (MM), because there > were no devices with
HYPERChannel got around the CCW-to-CCW latency issues by pre-loading the channel program into the memory of the local A51x channel adapter (box that emulated ibm mainframe channel and to which ibm mainframe controllers were attached). This also imposed a restriction that you couldn't do self-modifying ccw sequences ... and had a limit on the number of CCWs in a channel program. there was also an expanded A51x adapter, the A515 with additional memory and processing for DASD, ckd CCWS ... where the search argument was also preloaded into the memory of the A515 along with the dasd channel program (overcoming latency issues with search argument access). this, then imposed restriction on ccw programs that modified seek/search arguments. part of the issue with NSC's HYPERchannel product was that there had been this fiber-optic technology knocking around POK for a number of years that there were hoping to eventually get out (eventually released as something called ESCON) ... and the high-speed interconnect people in POK viewed HYPERchannel as something of competition. The other problem that the POK fiber optic people had was the whole SNA crowd. My wife had been con'ed into going to POK to be in charge of loosely coupled architecture ... where she had done peer-couple shared data ... that except for IMS hot-standby didn't see much uptake until parallel sysplex. in any case, she was constantly fighting the SNA group and thet all processor to processor interaction had to be SNA. there was something of a truce called where anything within the walls of the datacenter wasn't absolutely mandated to be SNA ... but anything the crossed the glasshouse wall boundary had to be SNA. this compromised then also created various difficulties for the people trying to get out high-speed fiber interconnect. various posts related to my wife's stint in pok in charge of loosely-coupled architecture ... and/or any of her activities in peer-coupled architecture http://www.garlic.com/~lynn/subtopic.html#shareddata slightly aggrevating the situation, prior to her going to pok, she had co-authored a peer-coupled network architecture published internally as awp39, that was viewed as a alternative to sna. misc. past posts mentiong awp39: http://www.garlic.com/~lynn/2004n.html#38 RS/6000 in Sysplex Environment http://www.garlic.com/~lynn/2004p.html#31 IBM 3705 and UC.5 http://www.garlic.com/~lynn/2005p.html#8 EBCDIC to 6-bit and back http://www.garlic.com/~lynn/2005p.html#15 DUMP Datasets and SMS http://www.garlic.com/~lynn/2005p.html#17 DUMP Datasets and SMS http://www.garlic.com/~lynn/2005q.html#27 What ever happened to Tandem and NonStop OS ? -- Anne & Lynn Wheeler | http://www.garlic.com/~lynn/ ---------------------------------------------------------------------- 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
