Date   : Sun, 24 Jul 2005 12:00:39 +0000
From   : Jules Richardson <julesrichardsonuk@...>
Subject: Re: ARM copros, speech cartridges, real time clocks,

On Sun, 2005-07-24 at 13:23 +0200, Mark Usher wrote:
> I was thinking interfacing the PC to an Econet network via USB.
> 
> The ISA Ecolink card that was produced, seemed to overcome the overheads by
> having a 6502 onboard.  When the driver was loaded, it download some
> microcode to the onboard processor. I did make a start on reverse
> engineering this some time ago, I can let you have the microcode block if
> you like.

I seem to recall the need for the 6502 was partly due to speed
limitations at the ISA bus, and partly due to the overhead in processing
on the PC itself. 

The second bit would unlikely be a problem these days. Not sure about
the former as I don't know what USB throughput is like compared to the
ISA bus.


Oh, I have heard a rumour that Econet for the VAX machines was done by
attaching a BBC micro to the VAX, and the VAX would talk to the BBC
(presumably over the 1MHz bus) and let the BBC do the interfacing to the
rest of the network. 

That might be an interesting project; allowing a PC to hook up to the
beeb's bus (except that's already what the Torch Graduate does :)

With a bit of ROM code on the bbc side it could give the PC Econet
ability, or allow fast transfers of data from the PC's disk to the BBC,
or let you use the BBC's floppy drives from the PC to do archiving etc.

cheers

Jules