Re: Ethernet card- alternatives

[ccw@ctt.bellcore.com (Christopher Wood)]

Someone wrote:

|> > |> Yeah, but for lack of an Ethernet card, what is there? Sure,
|> > |> there's that AppleTalk <> Ethernet thing, but AppleTalk is
|> > |> SLOW. I can't imagine FTPing through AppleTalk which runs at,
|> > |> what, 56.7k, when Ethernet runs at 4-10m/s?

I wrote:

|> > AppleTalk runs at 233K Bits/Sec; Ethernet has a nominal speed of 10M
|> > Bits/Sec, with actual throughput more like 1 - 3 Megabits/sec.  So
|> > LocalTalk and similar hardware (PhoneNet, etc.) is 4 to 12 times
|> > slower.  AppleTalk is the name of the entire protocol stack, and can
|> > (in theory) run on ATM at hundreds of Megabits to Gigabits per
|> > second... 

In article <9311161706.AA02356@fert2.fe.psu.edu>, jaj4922@fert2.fe.psu.edu (Jason A. Jeffries) writes:

|> That's strange; if our ports can really go 233k, I wonder why we can't use
|> them as serial ports that fast...

My recollection is a bit fuzzy; I've never studied a schematic, or
looked at the code.  Something about external clocking, and
synchronous vs. asynchronous timing.  When used synchronously, the
port reads in a byte, copies it into a buffer, and gets the next one,
without any interrupts between bytes. 

Chris

-- 
Chris Wood     Bellcore   ccw@ctt.bellcore.com