12 Dec
2005
12 Dec
'05
11:43 p.m.
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! 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.
[snip]
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
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).