> > The only folks that would really be in trouble are those who wrote code to > mathmaticaly map some data value into a CCHHRR value, which is what Direct > Access Method originally did. These people would have to come up with a way > to convert their "key" value to a relative record number instead of a CCHHR
VTOCs use keyed records, and AFAIK it's possible to share disks between DOS and OS families (heard of the DOS contamination bit?). The file I had in mind in the example below is the VTOC. BDAM can use keyed records. Partitioned dataset directories are keyed files. Or have these things changed over the years? > > > For VSAM it isn't that bad; and Relative Byte Address is a Relative Byte > > Address, on FBA it's a little easier becasue you just map from the first > > byte on the pack. VTOC's used the relative record approach instead of an > > CCHHRR. > > > > > > I was think more of the CKD disks' ability to store and recognise keys > as distinct from data. > > Mapping CCHR address is just a matter of simple arithmetic and bothers > me not at all. However, if my program logic is to search the file for > the record with the key "accounts.sourcelib" and read the data, then I > don't see how this maps to the FBA architecture. > > Unless the drives have that capability. > > > > -- > Cheers > John Summerfield > > Microsoft's most solid OS: http://www.geocities.com/rcwoolley/ > > Note: mail delivered to me is deemed to be intended for me, for my > disposition. > > ============================== > If you don't like being told you're wrong, > be right! > > > <font size="1">Confidentiality Warning: This e-mail contains information int > ended only for the use of the individual or entity named above. If the reade > r of this e-mail is not the intended recipient or the employee or agent respo > nsible for delivering it to the intended recipient, any dissemination, public > ation or copying of this e-mail is strictly prohibited. The sender does not a > ccept any responsibility for any loss, disruption or damage to your data or c > omputer system that may occur while using data contained in, or transmitted w > ith, this e-mail. If you have received this e-mail in error, please immedia > tely notify us by return e-mail. Thank you. > -- Cheers John Summerfield Microsoft's most solid OS: http://www.geocities.com/rcwoolley/ Note: mail delivered to me is deemed to be intended for me, for my disposition. ============================== If you don't like being told you're wrong, be right!
