[Coco] Re: Looking for I/O specs for DECB,Nitros,.....

[Brett K Heath]

On Tue, 2 May 2006 farna at att.net wrote:
[reformatted for line length]
> Is this going to run under DECB or Nitros9?

Hopefully both, either, or neither (see below).

> Big difference!

Really?
(sorry, I couldn't resist)

> DECB is just extensions to BASIC that allow direct access to disk
> functions, much as you describe with Forth. Nitros9 (and OS-9 in
> general), on the other hand, is a true DOS with calls. Not sure if that
> bit of info will help or not! Art Flexer is probably the one to speak to
> about DECB, Boisy Pitre about Nitros9/OS-9. Hope they have the tech info
> you need!

One of the less obvious advantages of most forth's is that they can quite
happily run without any OS at all, or they can adapt to and use whatever
system services are available (there are some constraints here, but
nothing that can't be worked with).

One of the particular strengths of the f83 implementation is that the
original authors factored almost all of the platform specific code into a
seperate source file, so you can boot the kernel with minimal drivers and
then load the appropriate file(s) for your environment. In fact, it's not
particularly difficult to have  drivers for bare metal, DECB, and OS9 all
available  and then select which one to use from the command line. You
could even switch between them on the fly (Not usually recommended, OS's
tend to get cranky when you bypass their disk routines, and yes I have
done this).

If you don't like wasting memory on drivers you don't use you can
recompile the system leaving out what you don't want, If you later need to
play with a different system (say you're troubleshooting the hardware) you
can load (compile actually) the drivers you need without recompiling the
whole system and when you're done consign them back to oblivion.

For that matter, if you have drivers and put the source files on tape it
would quite happily compile itself from them (though editing tape based
source would be more than a little tricky!).

There are constraints of course, but it really is remarkably flexible
system.

For the coco community as a whole the key point is that it can be adapted
to run (usefully) on anything from a tape based 16K CC1 up to and
including a 2 meg 6309 CC3 running Nitros09, and it comes with all the
tools needed to customize to your hearts content.

I've rambled enough for now, thanks for the reply.

Brett K. Heath