RE: Hooking display file I/O

["Joe Pluta" <joepluta@xxxxxxxxxxxxxxxxx>]

It is not Greek to me, Leif.  It is not entirely clear, but I've written
operating systems before, so I'm comfortable with the concepts of system
pointer tables (and the dangers of modifying them!).  I don't know how to
access the PCO, nor what is in it, but if there's a manual describing it,
I'm sure I can learn.

I have a basic understanding of the OS/400 implementation of pointers and
tag bits.  I have not used them yet.  The same holds true for MI.  As you
know, I purchased your book, and if it turns out that this project is
feasible, I will devote my free time to going through it.  Is your book
enough to give me a working knowledge of the pieces I will need?  If not, is
it a good starting point?  And what else will I need to learn?

Joe


> -----Original Message-----
> From: owner-mi400@midrange.com [mailto:owner-mi400@midrange.com]On
> Behalf Of Leif Svalgaard
> Sent: Sunday, August 05, 2001 11:43 AM
> To: MI400@midrange.com
> Subject: Re: Hooking display file I/O
>
>
>
> ----- Original Message -----
> From: Joe Pluta <joepluta@PlutaBrothers.com>
> To: <MI400@midrange.com>
> Sent: Sunday, August 05, 2001 10:57 AM
> Subject: Hooking display file I/O
>
>
> > One of my CFT (Copious Free Time) projects is going to be looking into
> > hooking the SEPT for display file I/O.  Has anybody done something like
> > this?  Please recognize that I'm an asbolute neophyte, and
> haven't a clue.
> > Is this project bigger than a breadbox?
> >
> > Joe
> >
>
>
> The way to do this is to monkey with a local copy of SEPT, instead of with
> the global system-wide SEPT. The PCO (Process communication obj)
> contains a pointer to the SEPT to be used by this process. Changing
> that pointer to point to your own copy (which you make with a single
> CPYBWP-instruction) requires you to set the tag bit for the pointer.
> SST can do that (the "T" flag). If the above is Greek to you,
> better not mess
> with it. BTW, a coming chapter (42?) of my ebook explores this in some
> detail.
>
> Leif
>
>
>
> +---
> | This is the MI Programmers Mailing List!
> | To submit a new message, send your mail to MI400@midrange.com.
> | To subscribe to this list send email to MI400-SUB@midrange.com.
> | To unsubscribe from this list send email to MI400-UNSUB@midrange.com.
> | Questions should be directed to the list owner/operator:
> dr2@cssas400.com
> +---
>

+---
| This is the MI Programmers Mailing List!
| To submit a new message, send your mail to MI400@midrange.com.
| To subscribe to this list send email to MI400-SUB@midrange.com.
| To unsubscribe from this list send email to MI400-UNSUB@midrange.com.
| Questions should be directed to the list owner/operator: dr2@cssas400.com
+---