View Full Version : Quick question about x86 networking...

April 2nd, 2009, 06:58 AM
I have an ISA 16-bit 10/100mbps Ethernet 3C515-TX card.
Tried Googling, but didn't come up with much yet.

Anyone know if a 386 can handle 10/100?

Um, I goofed. Can this be moved to hardware? :)

April 2nd, 2009, 07:15 AM
Um, I goofed. Can this be moved to hardware? :)

Sure! :mrgreen:

April 2nd, 2009, 07:50 PM
No one knows? Guess I'll have to try it.

April 2nd, 2009, 08:01 PM
It should work. I have a 486 ps/1 that I use for hardware testing and I think I remember using a 10/100 ISA 3Com on it for a time.

But empirical evidence is best, so have fun with it. Just be careful with the drivers, the ones that I used automatically with win95 only let it 'talk' at 10mbs. The driver disk let it talk at its full speed, though.

April 2nd, 2009, 10:50 PM
The reason that there are so few 10/100 ISA cards is because the ISA bus isn't really up to the job of handling sustained 100Mbps transfers. Yours will work, but obviously won't deliver the performance of a PCI 10/100 card.

April 2nd, 2009, 11:07 PM
ISA bus has a hard enough time using all the bandwidth of 10Mb since EVERYTHING goes over the ISA bus at the same time (HD, video, network) plus a 386 would not do DMA transfer on IDE so the poor CPU has to be traffic cop.

April 3rd, 2009, 10:08 AM
That's worse than I thought it would be. So, to keep things safe, best to stop the 10/100 at the 486-100 level, and go with the far slower ones, like the 5mbps for 386 and older. Would that make it a bit smoother?

April 3rd, 2009, 10:46 AM
Doesn't really matter much, actually. LAN traffic is packetized and every ISA NIC I've ever seen has local RAM for buffering. Regardless of card, you'll likely end up handling the same amount of data over a given period of time.

Where the 100Mbps comes in handy is where you have a lot of traffic on your LAN from many systems. Using a 100Mbps card will result in a transfer occupying less time on the network, leaving more available for other systems.

I'd stay with the 100Mbps for that reason.