Date   : Mon, 14 Nov 1994 11:22:40 -0600
From   : barnett@... (David Barnett)
Subject: Re: Catalogue info and emulated file system

Dave Lodge writes:

>Erm just curious...
>
>What is wrong with doing it like Acorn's Beeb emulator and just do a mapping
>translation from your current filing system on to your current filing system;
>and working out a map of spare attributes to beeb ones...
>
>I'm not certain about what attibutes DOS has; but all it needs are 3 (32bit)
>words and erm thats it...
>
>dave

Dave is right provided the info is available on your machine.

Most systems use relocateable code and so an absolute code address is
irrelevant to them.  Worth exploring case by case.  Best would be if there
is some sort of comment field in the host machine's catalogue.  You need to
be careful that placing info relevant to the emulator's memory map does not
cause probems to the host OS.

The optional header idea is a last resort (where the host gives no option).
It does, however, have one general advantage: one can use it is a
universal interchange format for beeb files.

Ideally, an emulator written for one machine in C should work on another
except for those routines which access the lower levels of the host's
hardware (these, I hope will be isolated as easily replaced host specific
modules).

Just a thought.

David Barnett