Acorn IEEE488 interface

[Tony Duell]

> > The article to find is in 'Electronics and Wireless World' February 1984, 
> > pages 24-26 ('IEEE488 interface for the BBC Microcomputer'). It imples 
> > the interface was actually designed by a company called 'Intellegent 
> > Interfaces'.
> 
> Indeed it is. I ran the IEEEFS ROMs which are available at the 'The BBC 
>    lives' site through a disassembler and both ROMs have a copyright 
> message saying '(C) Intelligent Interfaces Ltd and Acorn Ltd'.
> Could you scan the article? I'd be very interested in it!

Now where am I going to find a repairable scanner and something to 
connect it to?

> > I do. I think I might also have the IEEEFS ROM that goes with it, but I 
> > can't promise that.
> I wonder what version you've got. The 0.2 ROM seems like a beta version, 
> with lots of 'unused code' in between the different subroutines, and the 
> 0.5 ROM hasn't got any filesystem support, just support for the OSWORD 
> calls.

I will try to find it. It will take some time, though....

> 
> [snip]
> 
> > Hmm, I see what you mean. The manual looks very comprehensive with lots of 
> > examples - but I can't see where it justifies why the addressing is done in 
> > this way.
> 
> I think it was done so the IEEE interface could be accessed as an 
> ordinary file system (file handles &F0-&FF were reserved for IEEEFS IIRC).

Yes, but why not do a modified version of the HP method (at least on 
older machines). Have a file called 'DATA' that talks to the currently 
addressed talker/listener. And send the appropriate commands to the 
'COMMAND' file to address devices. I think that would have been a lot 
clearer.

-tony