Date   : Sat, 14 Oct 2006 23:56:43
From   : jgh@... (Jonathan Graham Harston)
Subject: Re: Tube Documentation

"David Harper" <dl.harper@...> wrote:
>  Jonathan Graham Harston wrote:
> >> be called from within DOS-Plus, provided appropriate Tube claims and
> > No, the host (ie, the IO processor) does the claims and releases
>
> Sorry, but I must correct this. When DOS-Plus is running there is a separate
> Tube claim and release that has to be done from the client processor. (Claim
> is done by XIOS call 81h and release by 82h.) A client program running

Ah, I see what you mean. That's not claiming the Tube, it's
claiming the 80186 client MOS. They are actually get/release Tube
semaphore, and are effectively "I want to use INTs 4x", "I no
longer want to use INTs 4x" calls.

> If any programs were written to run from the 80186 Monitor rather than
> DOS-Plus, then they would not need to make these claims. Has anyone ever
> written such a program?

BBC BASIC 86 for the Master 512 uses INT 4x to allow more access
to BBC MOS functions than BBC BASIC 86 for DOS would give you.

> > The 80186 client code is the only one I don't have. I don't
>
> I will send it direct when I get a chance. There is more than one version of

Got it. Thanks. Started disassembling it and recreating it as
source code. Damn it! I've had to sit down and learn 80x86
assembler! Horrible stuff. I shall never forgive you :)

> it, and I only have one of them at present, but I will send the one I have.
> If I remember correctly from when I last examined it there is only 16K of
> it, despite what the circuit diagram appears to show, but I will check. The

The diagram shows two 16K ROMs, but with that socketing you can
use anthing from 2*4K up to 2*16K.

--
J.G.Harston - jgh@...                - mdfs.net/User/JGH
United Kingdom Tercentenary : 1707-2007 : http://yr300.org.uk