Path: utzoo!attcan!uunet!mcsun!unido!sbsvax!roeder
From: roeder@robin.cs.uni-sb.de (Edgar &)
Newsgroups: comp.sys.atari.st
Subject: Re: How can I find current DTA address w/o using TRAP #1?
Message-ID: <ROEDER.90Oct1153314@robin.cs.uni-sb.de>
Date: 1 Oct 90 14:33:14 GMT
References: <5429@bdt.UUCP>
Sender: news@sbsvax.cs.uni-sb.de
Organization: Universitaet des Saarlandes, Saarbruecken (W-Germany)
Lines: 20
In-reply-to: ADAM_TILGHMAN@bdt.UUCP's message of 29 Sep 90 20:59:53 GMT

In article <5429@bdt.UUCP> ADAM_TILGHMAN@bdt.UUCP writes:

> I can't find the current DTA address;  is there any way that I can
> do this while processing a TRAP #1?

The current process' DTA address is recorded in the basepage which can
be derived from the act_pd system variable (this in turn is recorded
in the sys_base (the first few bytes after the ROM-start) for TOS
versions >= 1.2).

BTW.:
You should be able to call trap #1 recursively if you do it inline
(for example in assembler) and avoid library routines that save the
return address in a static memory location. The shell that i am using
(Master) calls trap #1 very often in this way (even from inside a
bios-trap --- but that's another story).

Hope this helps!

	- Edgar