Re: TI-H: special component

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Re: TI-H: special component


Save yourself a huge amount of trouble, buy a 386 DX/8MB at a computer
or ham show, and get a cheap 10mbit nic. You can probably get everything
you need for under $80. Go home, install linux, and you're set. I think
doing this kind of thing from the ground up yourself would be like
trying
to redo 10 years of PC hardware and software development!

Bryan

Jon Olson wrote:
> 
> Don't you think that the chip would however, get backlogged with data after
> a while? i mean...it could in theory bring in the data and send it back out
> that quickly, however if it's planning on doing anything real with the
> data, i don't think that this will work at all well. however, if you can
> find a way to make it work on a 10 Mhz network. Please tell me. I've been
> considdering building a little device that connects to a modem and to my
> dad's office network and allows me to dial in and execute various tasks
> (i.e. reboot my servers there, connect via telnet to some of the firewalled
> workstations, that kind of thing).
> 
> At 08:33 AM 6/18/98 -0700, you wrote:
> >
> >On Thu, 18 Jun 1998, Jon Olson wrote:
> >
> >> Seeing as the PIC only operates at 10 Mhz and the network operates at 100
> >
> >Just a minor technicality, but I think the high-end PICs max at 20MHz..
> >
> >They take 4 clock cycles to make an instruction cycle, so it's getting 5
> >MIPS. A 10 Mb/s (megabit) network (in theory) pushes 1.25 MB/s (megabyte)
> >of data. So if you had some sort of a shift register taking the data from
> >the network line and presenting it a byte at a time, then I think a 20
> >MHz PIC would be able to switch 10 Mb/s network traffic. (Did I calculate
> >all that correctly?) A 100 Mb/s network (also in theory) moves 12.5 MB/s
> >down the line. Since a PIC can read its I/O ports in a single instruction
> >cycle, it can take in 5 MB/s at 5 MIPS. So it has enough room left over to
> >push 10 Mb/s traffic back out another port, but it doesn't have enough
> >power to even read in a 100 Mb/s source without losing frames.
> >
> >So anyway, like Jon said, 100 Mb/s traffic is definitely out. But I think
> >10 Mb/s might be possible... unless I don't have a clue what I'm doing,
> >and that is also possible.
> >
> >--
> >Greg Hill
> >greg-hill@bigfoot.com
> >www.comports.com/link
> >
> >

-- 
Bryan Rittmeyer
mailto:bryanr@flash.net
http://www.bridges.edu/horizon/
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