Grzyb wrote on 2026-04-27, 10:43:

3C509B is ISA.
3C905B is PCI, and its COMBO variant is a rare example of 100 Mbps card with AUI and BNC ports.

Sorry, I swapped the numbers. Yep, 3Com ISA NIC, that I have, is EtherLink III 3C509B-C(ombo). I also have a cut-down version with RJ45 only and no boot ROM - EtherLink III 3C509B-TPO.

The PCI 3Com card, that I have, is Fast EtherLink XL 3C905B-TX. I also use this one for XTIDE on Pentium-class and newer systems.

DaveDDS wrote on 2026-04-27, 03:28:

fosterwj03 wrote on 2026-04-26, 17:24:

I like the Dec 21140 chip because it's one of the few PCI network interfaces that have Windows NT 3.1 drivers.

I've got a few Realtek {mumble - I can figure out the model number if anyone cares} that are PCI and are fully NE2000 compatible, which is compatible with almost all OSs. It's been years, but I'm pretty sure they worked on NT 3.1, 4, 2000 also used them with Wfw 3.1, 95, 98 etc.

One more important thing:
DEC 21140 is 100 Mbps
NE2000-compatibles are 10 Mbps

So, for NT 3.1, the 21140 clearly wins.
PCI NE2000 cards may come in handy for other systems.

DaveDDS wrote on 2026-04-27, 03:28:

I've got a few Realtek {mumble - I can figure out the model number if anyone cares} that are PCI and are fully NE2000 compatible, which is compatible with almost all OSs.

Realtek’s PCI NE2000 clone is the 8029A and its ISA NE2000 clone is the 8019A.

Most of them end in -AS instead of just -A. The S version is an integrated design that also contains 16K SRAM buffer. I have not seen one with the buffer in separate chip, but apparently some might exist.

Grzyb wrote on 2026-04-27, 10:43:

3C509B is ISA.
3C905B is PCI, and its COMBO variant is a rare example of 100 Mbps card with AUI and BNC ports.

The 905 series has a B and a C variant.

B is called “vortex” and says ParallelTasking(tm) on the chip.

C is called “cyclone”

Not sure if the difference between the two is night and day, just thought the factoid might be interesting.

st31276a wrote on 2026-04-27, 12:49:

The 905 series has a B and a C variant. […]
Show full quote

Grzyb wrote on 2026-04-27, 10:43:

3C509B is ISA.
3C905B is PCI, and its COMBO variant is a rare example of 100 Mbps card with AUI and BNC ports.

The 905 series has a B and a C variant.

B is called “vortex” and says ParallelTasking(tm) on the chip.

C is called “cyclone”

Not sure if the difference between the two is night and day, just thought the factoid might be interesting.

I have a 3Com 3C905CX-TX-NM in one of my builds, the Windows software is quite nice and it works fine without much CPU overhead. No idea if it's a C or B variant.

st31276a wrote on 2026-04-27, 12:49:

The 905 series has a B and a C variant.

Only the B variant is available in the COMBO configuration.
Again: 100 Mbps COMBO cards are rare, and may come in handy.
Back in the era, they were precious for those with 10 Mbps coaxial network, who were planning to replace it with 100 Mbps twisted-pair.
Today, they are precious for those who want to use modern LAN, but also experiment with historical coaxial equipment.

songoffall wrote on 2026-04-27, 13:01:

st31276a wrote on 2026-04-27, 12:49:

The 905 series has a B and a C variant. […]
Show full quote

Grzyb wrote on 2026-04-27, 10:43:

3C509B is ISA.
3C905B is PCI, and its COMBO variant is a rare example of 100 Mbps card with AUI and BNC ports.

The 905 series has a B and a C variant.

B is called “vortex” and says ParallelTasking(tm) on the chip.

C is called “cyclone”

Not sure if the difference between the two is night and day, just thought the factoid might be interesting.

I have a 3Com 3C905CX-TX-NM in one of my builds, the Windows software is quite nice and it works fine without much CPU overhead. No idea if it's a C or B variant.

That is a C variant.

The NM means non-managed or non-management or something in that direction. Apparently -M variants had management features and was a corporate-ready buzzword justifying extra expense. What those management features were and how much of it is actually hardware based I do not know.

Grzyb wrote on 2026-04-27, 11:07:

... One more important thing: ... DEC 21140 is 100 Mbps ... NE2000-compatibles are 10 Mbps

Fair enough, I have to say I rarely care enough about network speed to make a distinction. For me, NE2000 (ie: universal) compatibility is worth a lot more than "latest and greatest".

I really never "got" the fixation on speed. My first network was a simple 10base2 hub (Coaxial cables, BNC connectors, and everything went everywhere - every system shared bandwidth, the hub just enables spreading out - everything is effectively on one wire)

This was so much faster and easier than my traditional way of moving data (sneaker-net or serial connections) - I really appreciated it.

As my network has grown, I replaced the hub with 100baseT switches, and now have at least 1/2 dozen such nodes now... And yes, on very large transfers it is slightly faster, but in my everyday usage (modern systems with built in 100mbps+ nics) I don't really notice the difference much at all.

I never bothered to go gigibit (or anything faster than 100), just never felt the need (and to be fair the main reason I've upgraded from 10 to 100 is that 10 stuff became obsolete and you couldn't get it - and I like the idea of a "switched" interconnect - to me this is far more important then speed).

I still have one 10baseT hub in the far corner of my workshop where I have a few DOS systems ... (some running NE2000 compatibles) and I don't really notice much difference transferring between/to/from them and between/to/from modern systems either) - it really depends on your type of traffic, and IMHO few people understand how fast 10mbits actually is!

Yes, a lan is actually insanely fast. It has to be, since when the concept started out whole segments shared the medium. You have to be able to transmit and get out of the way of others. Today, we have this entire bandwidth to ourselves in our homes and labs.
Gigabit is only nice for very large transfers of disk images and media.

Are people forgetting that if your LAN is only 100mbit, the speed to your modem/router (i.e. internet speed) is also capped at that...

DaveDDS wrote on 2026-04-27, 16:16:

the main reason I've upgraded from 10 to 100 is that 10 stuff became obsolete and you couldn't get it

Yes, and nowadays it gets to another level - some modern switches completely drop 10 Mbps compatibility.
Sometimes the most convenient solution is to install 100 Mbps (or faster) NICs everywhere...

Fortunately I have enough 10-100 switches (technically I think you would only need one), so the idea of finding new NICS for the old ISA-only boxes doesn't have to be a thing.

Agreed.

I see some of the 10 gig stuff even drop 100 support.

Luckily me to has a stash…

I remember what was probably a bug end 90's with Ne2000 cards .
There was a dos program to configure them as Half duplex or Full Duplex.
But when they were configured in Full Duplex from this, in fact under Linux they were Half ...
With a friend we've spend days trying to understand why our Linux LAN was so slow 😀
When you use a 10M card and amputate it , the results are not very fast 😀
I think using RJ45 cables was even slower than BNC.