auron wrote on 2021-04-16, 01:11:

to quote the driver readme for these S82557-based cards: […]
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to quote the driver readme for these S82557-based cards:

MSWIN95.txt wrote:

EtherExpress PRO/100B TX adapter: Supports auto-negotiate, full and half duplex at 10 or 100 Mbps. […]
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EtherExpress PRO/100B TX adapter: Supports auto-negotiate, full
and half duplex at 10 or 100 Mbps.

EtherExpress PRO/100B T4 adapter: Supports full and half duplex
at 10 Mbps; supports only half duplex at 100 Mbps. Auto-
negotiate is not a valid option at either speed.

so, is there a proper way to find out which version one has? i might possibly be answering my own question here but on the card i have, next to the "LNK", "ACT" and "100" cutouts there is also "TX" engraved but no cutout and there's a transistor on the board instead of an LED, so i'm assuming my card might be the T4 version.

this difference really doesn't matter much when using these things just for unidirectional file transfers these days but it's quite astonishing how they sold a gimped version under basically the exact same name - i've never even seen that T4/TX referenced before reading this file and the driver doesn't seem to mention it anywhere either, at least the one that comes with 98se.

It's not so much that 100BASE-T4 is gimped, but that it enabled 100Mbps over lower grade cabling CAT3 cabling and used 4 copped twisted pairs . If you are using 2 T4 cards to send mainly one-way traffic, it would not matter much. If, however, you intend to use a 100BASE-T4 in a "modern" (100BASE-TX or 1000BASE-T) network, you might end up running at 10Mbps speeds since, AFAICT, newer equipment is unlikely to be 100BASE-T4 backwards compatible and will thus downshift the connection to 10BASE-T .

I am going from long-term memory on this, so please feel free to correct any inaccuracies .

well it also lacks auto-negotiate so that could be an issue depending on what you connect it to, so i would definitely call that gimped. i was able to set 100mbit in the driver and got 2.6 megabytes per second out of this card under 98se, which exceeds 10mbit speed and would suggest it's the TX version after all. but if the T4 cards can't even do 100mbit on modern networks, that would be all the more reason to avoid them unless you're fine with an ISA speed card on PCI.

wonder what part is different on the T4 cards, the transceiver maybe? the one on mine is a pulse PE-68515 and seems to be listed as 100BASE-TX capable in some sources, but the datasheets generally just seem list 100BASE-T, and same for the H1012 part that was also used on these cards. could also be a very good chance they just gimped some of these via card firmware and sold them a bit cheaper...

just for posterity, i eventually did find the intel site describing how to tell these versions apart, and my card is the TX version, as expected: https://web.archive.org/web/20000305031431/ht … RO100/21397.htm