Excerpted from a message dated 12-29-98, Ivan gTodoroski to Murray
Lesser:

 ML>     AFAIK, HPFS is not the _only_ good thing to come out of MS. but it
 ML> may well have been the last one :-).  I still use (on rare occasion) the
 ML> MS BASIC PDS v 7.1 compiler, which can put out 16-bit text-mode, OS/2
 ML> programs.  Unlike many later compilers, it includes VSAM file management
 ML> as a built-in capability.  (IIRC, HPFS first appeared on OS/2 v 1.1;
 ML> BASIC PDS was written for OS/2 v 1.0.)

IT>   At the risk of sounding ignorant, what exactly is PDS and VSAM?

Hi Ivan--

    BASIC PDS (Professional Development System) v 7.1 was the last
_good_ BASIC compiler (vintage 1990) put out by Microsoft, and the only
MS BASIC compiler that recognized that OS/2 existed.  While it offered
graphics for DOS, the OS/2 version (both in the same package) was
text-mode only, because OS/2 1.0 had no graphics capabilities.  The only
programs I use it for were written long ago.  Yesterday (30 December), I
updated my ancient BASIC financial record-keeping program for 1999.  I
wrote the program originally in 1987 for a predecessor of BASIC PDS. The
program was written to include an easy method (using the "find and
replace" command in my editor) to update the source code for each new
year; it never had a Y2K problem!  It still does everything I want it to
do, so it is far down on my list of applications to be ported to PL/I.

    I have to admit to an error in the post you quoted.  BASIC PDS
supports ISAM (Indexed Sequential Access Method) developed by IBM in the
early 1960s for its first "large capacity store."  From the PDS
Programming Guide:  "When a file contains many complex records, sorting
can require substantial program code and a great deal of processing
time.  ISAM is an approach to creating and maintaining a special data
file, in which the way records typically need to be sorted can be easily
defined and efficiently stored along with the records themselves."

    VSAM (Virtual Storage Access Method) is a later IBM mainframe access
method (included in PL/I for OS/2) that includes ISAM as well as a few
other useful file access methods.

    Regards,

        --Murray

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