Re: RPG400 SDA query? -Reply

[Scott Cornell <CORNELLS@xxxxxxxxxxxxxxx>]

>>> <boothm@ibm.net> 10/22/97 10:25pm >>>

  <<snip>>
>> Use pointers & based variables.
>>
>> John Carr

> This is a question based upon what I was
> told once:  I was told that one reason
> the AS/400 is so stable and the file
> structure is so stable is that is is not
> a pointer-based system.   Now I suspect
> that may have been an old wive's tale. 
> So...  how come we don't use a PC-based
> file system?

            -------------

Thus beginneth the gospel according to
Scott:

Answer #1 - yeah, not having the ability to
store my latest stock price quote in the
memory address of the base operating system
has tended to make the AS/400 a tad more
stable than your average PC ;-)  However, I
believe OS/400 still protects you from
disasters of this nature - I think your
"based on pointer" variables are still
restricted to your job's "data space" in
it's own Pgm Activation Group (I'm not sure
of the correct terminology, but the concept
is valid), so even an invalid pointer
address will "only" trash your program's
data & leave you job (and, thankfully, the
entire system) intact.

Answer #2: isn't the IFS supposed to be a
PC like file system?

'Course, both these beasties are realtively
new capabilities on the AS/400, so your old
wives aren't wrong, just somewhat out of
date.

Scott Cornell
Mercy Information Systems
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