re: http://www.garlic.com/~lynn/2010l.html#76 History of Hard-coded Offsets http://www.garlic.com/~lynn/2010m.html#1 History of Hard-coded Offsets
the thing that even made the 3390 statement possible was the existance of the whole additional complexity of the CKD virtualization layer on top of FBA devices; aka there is no longer any direct relationship between what the system thinks of as DASD CKD geometry and what actually exists (something that the underlying FBA paradigm had done for the rest of the industry back in the 70s). misc. past posts on the subject of FBA, CKD, multi-track searches, etc http://www.garlic.com/~lynn/submain.html#dasd as I've commented before ... I was told that providing fully integrated and tested MVS FBA support, it would still cost an additional $26M for education, training, publications to ship ... and the business justification had to show incremental profit that more than covered that $26M; aka on the order of $300M or so in additional DASD sales directly attributable to FBA support (then the claim was that customers were buying DASD as fast as it could be built ... and the only thing that FBA support would do, was switch same amount of disk sales from CKD to FBA). It was not allowed to use life-cycle cost savings ... either internal cost savings or customer cost savings as business justification for shipping FBA support. -- virtualization experience starting Jan1968, online at home since Mar1970 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html