Date   : Fri, 10 Jul 2009 08:18:40 +0100
From   : info@... (Sprow)
Subject: Master ethernet upgrade

In article <DA32CC9DC57B4590845525A30E49591E@...>,
   Michael Firth <mfirth@...> wrote:
> > Please note: for electrical reasons this upgrade can only be fitted to a
> > Master or Master Compact,
> > Sprow.
>
> The question that springs to my mind first is whether a version could be 
> produced that connected to the 1MHz bus instead, to allow either 
> connection 
> to a BBC B/B+, or for a Master to have both the Ethernet interface and an 
> Econet module fitted, to allow some form of bridging?

I wanted to carefully avoid an external Econet to Ethernet bridge as I know
that's something Phil/Mark are working on. This kit is something different
and I hope non overlapping.

> Presumably even the Econet hosted version would not be able to keep up 
> with 
> a full rate 100Mbit/s transfer, as it only has 2MHz x 8 bits = 16Mbit/s 
> bandwidth available to it?

Correct: 10/100Mbps is the link rate, actual useful payload is ultimately
governed by the 6512 so even 16Mbps is unlikely (afterall, you'd need some
instructions in between the 2MHz accesses). The ethernet chip has some
decent FIFOs in it so can offload some of the work.

For LANManFS, load/save speeds are of the order of 10/15 kilobytes per
second in version 0.25,
Sprow.