3C509B is well-known to work on XT, just make sure you have the appropriate packet driver:
http://www.vcfed.org/forum/showthread.php?305 … 4266#post224266

I don't recall any option to select 8-bit bus, just make sure to select some IRQ that's available on 8-bit ISA - the default setting for many 8-bit NICs is IRQ 3.

Like so many others I stuck with 3com (and Intel) NICs purely because at the time they were everywhere - and they just worked out of the box without having to find drivers - I've never done any actual performance comparisons between them and lesser cards. For the same reason I have a stack of Xircom PCMCIA and CardBus cards for old laptops - they just work and drivers are already included on the Windows ISO from Win95 onwards.

Grzyb wrote:

3C509B is well-known to work on XT, just make sure you have the appropriate packet driver:
http://www.vcfed.org/forum/showthread.php?305 … 4266#post224266

I don't recall any option to select 8-bit bus, just make sure to select some IRQ that's available on 8-bit ISA - the default setting for many 8-bit NICs is IRQ 3.

Now that is some very clever work! Thx for the link. Is there an option for no IRQ, if all we want to use the card for is map a EPROM into the boot rom space?

I don't think so, but then you can probably set an irq outside of the 8bit ISA range and that'll be enough

Also, a NIC only generates IRQ signal when it receives a packet from the network, so if you don't connect the net, there won't be any IRQs.

They where just popular on the PC platform. ( ISA, EISA, MCA, PCI ).
They had good reliability, driver support and easy to install and setup.
3com drivers where included in Novell server, client, WIn3.11, Win-NT 3x 4x , Win 95, Win98, Win2000.
But Intel NIC’s are just as good if NOT better.
So are DIgital
And AMD Nics.
Realtek and all the rest are just as good in PCI form.
Most are plug and play with Win95 and up.
Novell NE2000 compatible Nic’s Where inexpensive and gave 3com a price war.

Today, I prefer Intel and Cisco and Linksys and Apple for all my home network needs.

Just looking at all the (Fast) Etherlink XL subvariants. I've found these:

• 3C900-C / 3C900-COMBO
• 3C900-TPO
• 3C900B-C / 3C900B-COMBO
• 3C900B-CMB
• 3C900B-FL(ST) [this is a fiber channel card]
• 3C900B-TPC
• 3C900B-TPO
• 3C905-T4
• 3C905-TX
• 3C905B-C / 3C905B-COMBO
• 3C905B-FX(SC) [fiber channel]
• 3C905B-T4
• 3C905B-TX
• 3C905B-TX-M
• 3C905B-TXMBA / 3C905B-TX-MBA
• 3C905B-TXNM / 3C905B-TX-NM
• 3C905B-TXPXE
• 3C905C-TXM / 3C905C-TX-M
• 3C905C-TXM(B)
• 3C905CX-TXM / 3C905CX-TX-M
• 3C905CX-TX-NM
• 3C905CX-MLP

Are there any others? Which is best?

The two I have are: 3C905B-TP and 3C905B-C. The "C" board is fully populated, while the TP apprars to only support the RJ45. It is missing the BNC coax connector and the cluster of components on the pcb behind the DB15.

I used an 8 bit 3com card to get on the college network

I got it free and it was all I had back in a time when any network card was $30+

It worked great under Windows 95 even though it was ancient

Errius wrote:

3C905CX-MLP

A NIC for My Little Pony fans? 😁

Anyway, I like the 3C905B-COMBO - probably the only 100 Mbps card with BNC and AUI connectors.
Back in the era, it was useful for those who had coaxial cabling, but planning to replace it with twisted-pair for 100 Mbps.
Nowadays, it's useful for bridging between a modern LAN, and a coaxial segment with older machines.

Intel486dx33 wrote:

They where just popular on the PC platform. ( ISA, EISA, MCA, PCI ). They had good reliability, driver support and easy to insta […]
Show full quote

They where just popular on the PC platform. ( ISA, EISA, MCA, PCI ).
They had good reliability, driver support and easy to install and setup.
3com drivers where included in Novell server, client, WIn3.11, Win-NT 3x 4x , Win 95, Win98, Win2000.
But Intel NIC’s are just as good if NOT better.
So are DIgital
And AMD Nics.
Realtek and all the rest are just as good in PCI form.
Most are plug and play with Win95 and up.
Novell NE2000 compatible Nic’s Where inexpensive and gave 3com a price war.

Today, I prefer Intel and Cisco and Linksys and Apple for all my home network needs.

Until 1000baseT became a thing, 3com were unrivaled in performance. Intel and DEC made good chipsets, but they still used more CPU for the same throughput. I love Realtek nics for being cheap, ubiquitous, and having dead simple packet drivers, but high performance they were not.

I cannot find my post where I benchmarked the transmission rates of various network cards on a 486, but sort of recall the 3com’s and Intels yielding similar performance. I an NIC in every system. It makes file transfer easy for that new benchmark or game you just discovered, or for making your old system suffer trying to load a webpage.

For ISA NIC cards, you are restricted by the bus if using 10/100 cards, but for the less patient, I recommend the 100mbit ISA cards as they transfer 2-4x faster than a 10 mbit card. The 3com 10/100 ISA card is harder to find and over priced, but the IBM-branded Intel 100 PRO cards can be had for reasonable sums. For ease of setup and Windows-included drivers, the 3COM Etherexpress III is a good 10 mbit card.

intel had better drivers and intel drivers are supported better across multiple platforms. That being said there was a time when 3com was the best it just happened before later revisions of intel pro 100 nics which was about the time 3com sold out to broadcom who had already been fabing for them for some time.

There's a guy who tested quite a lot of mid '90s nics. The one that came on top was SMC nics were a bit snappier than even 3Com. I just use what works and usually the first out of the box.I've had good success with KYE/Genius DE 200 series nics. Using four at present in various systems. In fact Ive had good servise from a lot of KYE/Genius hardware. The nics had drivers for every major OS-NT, OS/2, Win9x, Novell Netware, as well as Dos packet drivers.

I worked compute clusters in Uni. Trust me, at least in the Linux world 3com was the performance king.

gdjacobs wrote:

I worked compute clusters in Uni. Trust me, at least in the Linux world 3com was the performance king.

Which timeframe are we talking about?

The ISA 3Coms such as the 3C509 use programmed I/O, which tended to be slower than shared memory or DMA designs used by contemporary SMC or AMD designs respectively. I recall SMC ISA cards being considered the fastest out there. The later 100MbE PCI cards were pretty sweet for their time though, with hardware checksumming implemented on the 3C905C.

PCI era. The 3c503 used shared mem, so performance was roughly equivalent with the WD8013/SMC Ultra line. We had a lot of SMC ISA cards in legacy gear elsewhere in the department, and I definitely liked those. In the PCI era, the 3c905 was the bees knees.

Intel486dx33 wrote:

3com drivers where included in Novell server, client, WIn3.11, Win-NT 3x 4x , Win 95, Win98, Win2000.

This was the selling point for me.

3C905 was <3

This question was one I wanted to subject to some empirical comparison, so this evening I sorted out a test system and got cracking. I was only able to test PCI, as getting ISA cards working under Knoppix was a challenge for another day.

Server:
Phenom X4 925
4GB
Asrock AM2NF3-VSTA (nForce3)
Intel Pro/1000MT GbE
Lubuntu 19.04
Linux 5.0.0
iperf 2.0.12
iperf -s

Client/test box:
Pentium 3 500E
512MB
DFI TA64-B (Via ApolloPro 133A)
Knoppix 5.1.1 (installed onto HDD)
Linux 2.6.19
iperf 2.0.2
iperf -c xxx.xxx.xxx.xxx -P5 -t30

Throughput measured with iperf on the client, CPU usage the highest value seen in top. No other software running at same time.

NIC Vendor NIC Model Bus Chip Vendor Chip Model Throughput CPU usage
3Com 3C905CX-TX-M PCI 3Com 920-ST06 93.8Mbps 16.2%
3Com 3C905C-TX-M PCI 3Com 920-LU00 94.1Mbps 19.5%
Noname Noname PCI Realtek RTL8139B 94.1Mbps 18.7%
Intel Pro 100/S PCI Intel 82558EY 93.7Mbps 22.8%
Compaq NC3120 PCI Intel SB82558B 93.8Mbps 22.8%
Compaq NC3122 PCI Intel SB82558B 93.9Mbps 23.8%
Fast Line IMI21143 PCI Intel/DEC 21143PD 93.1Mbps 20.2%
Noname 142208+402 PCI Realtek RTL8029AS 9.03Mbps 01.7%

Pretty simple TCP throughput test here, five parallel iperf threads - but one where things like checksum offloading can make a difference.

Actual speed results are close enough to be considered a virtual tie (apart from the 10MbE card). CPU usage does differ significantly though, with the 3C905CX-TX-M clearly utilizing the CPU less than other cards. Surprise result is that the RTL8139B actually beats the Intel and DEC-based cards in this metric. Possibly a more diverse workload would give the Intel NICs a chance to shine, but the only conclusion here is that - at least when running on a relatively fast system and using Linux - you are best off with a late PCI 3Com card, but failing that that a cheapo noname Realtek card is a decent second choice.