Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!uunet!mcsun!ukc!warwick!cstxqbt
From: cstxqbt@warwick.ac.uk (CrisP of Truth and Justice)
Newsgroups: comp.sys.amiga.tech
Subject: Custon AmigaDOS DEVS.
Message-ID: <508@lily.warwick.ac.uk>
Date: 2 May 90 10:15:23 GMT
Reply-To: cstxqbt@warwick.ac.uk (CrisP of Truth and Justice)
Distribution: comp.sys.amiga.tech
Organization: Computing Services, Warwick University, UK
Lines: 22

Hi.

  Here, is a subject that does not seem to be documented much. I would like
to write my own AmigaDOS device. I have looked at all the information I have
and all I can work out is that when you have to have a handler file. This
handler file is specified in the entry in the MountList file. I have had a
look at the handler files on my disks. I know they are executable files. They
all seem to have a funny first word. What is this for? What are the registers
set to on execution of the handler? The only reference to them I have is in
the Kickstart guide to the Amiga, but this does not go into any detail about
anything. From that I gather that the handler runs as a process through which
the I/O is performed. How is it done? I assumed it was done by the Exec
MsgPort in the process structure. Is this so? What protocol is needed? I need
to handle reads writes and closes. How do I recognise these and what do I do
if its something I am not intrested in? I also need to know the stuff after
the device name. So if the user opens "MYDEV:blerb" I need to know the blerb.
  If no one answers this I might just have to resort to hacking Populous.
There's some interesting copy portection!

- CrisP.

What's a .sig file?