Date   : Wed, 27 Jul 2005 20:52:48 +0100
From   : Rob <robert@...>
Subject: Re: Econet-Ethernet bridge

At 16:00 27/07/2005, Jules Richardson wrote:

>On Wed, 2005-07-27 at 15:50 +0200, Johan Heuseveldt wrote:
> > Iyonix computer doesn't have a parallel port anymore. New printers also
> > seem to come without one (only USB and/or network).
>
> >From a hacker point of view that's a shame :-(

The last new laptop we bought (about a year ago) didn't have anything other 
than USB ports - not even cardbus!



> > So, Econet for Beebs is at max 200 kHz, which is bit speed. Byte speed
> > will then, lets say, 20 to 25 kHz. (20/10, 20/9, 20/8)
> > Is that (really) a problem for parallel/Centronics?
>
>I *think* you can get about 100KB/s through a parallel port, so it
>sounds like that *could* work comfortably with buffering at the byte
>level.

Well, you could get 10Mbps parallel port ethernet adapters, so this would 
perhaps be easier?



>Just depends whether it's possible to work at the byte level across that
>interface boundary - which depends on the nature of the Econet protocol
>itself (if it needs to work at the bit level at any time then control
>via the parallel port - operating at byte level - might be difficult)

Well .. the 68x54 has a 3 byte FIFO for line traffic; bits are shifted out 
onto the line internally.  The flag registers are all loaded or read a byte 
at a time too.


Personally, I'd like an integrated ethernet<-->econet box, not something 
that requires a PC to drive it...   Surely the cost of the microprocessor 
and ethernet chip is not going to be significantly different to the cost of 
a larger board and glue logic to be a PCI card, or the chips required to 
present any other form of interface.

Heck, ethernet is pretty much the standard interface for networking; 
everything here has it, in one form or another, even some of the really old 
systems, apart from the beebs, but in terms of other interfaces, very few 
systems here have all of serial/parallel/USB to choose from ..


Now if I could print from the beeb (it thinking it's talking to an econet 
print server) direct to the laser (connected directly to my ethernet) 
that'd be worth it in itself..