Marco wrote on 2025-10-22, 14:03:

hello, […]
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hello,

I surfed through a lot of forum content here and came quite often across the message „3c509 supports (busmaster) DMA“.

Question:
I could never find any setting to configure DMA on such card (509cfg.exe etc).

Am I using the wrong versions? Do you have different experiences?

Thank you

The 3C509 does not support bus mastering. It uses programmed I/O (PIO) exclusively. See Chapter 2, "Architectural Overview":
https://www.janwagemakers.be/PIC18F452_3COM_3 … rnet/3c5x9b.pdf

Ah thanks a lot for the clarification. It will be then the 515 only - for 3com Isa NICs

Marco wrote on 2025-10-22, 16:09:

Ah thanks a lot for the clarification. It will be then the 515 only - for 3com Isa NICs

The 3c515 (Fast EtherLink XL, codename "Corkscrew") is the only ISA 3Com ethernet card using busmaster DMA. But the 3c505 (EtherLink Plus) also uses DMA, this time it is standard ISA DMA. Possibly that card can be used in PIO mode too, that's how some Linux commits sounded that popped up on Google on a quick research.

Thank you. Just to be really sure: 3c515 is the short form for the 3Com 3c515 ISA Fast EtherLink XL or is the XL corkscrew a specific version? I couldn’t find differences in the web

The official name is...

"Corkscrew" is the codename.

"EtherLink XL" is the 3C90x series.

Marco wrote on 2025-10-22, 16:37:

Thank you. Just to be really sure: 3c515 is the short form for the 3Com 3c515 ISA Fast EtherLink XL or is the XL corkscrew a specific version? I couldn’t find differences in the web

3c515 is the model number for the product officially named "3Com Fast EtherLink ISA 10/100BASE-TX Network Interface Card". While I used the name "EtherLink XL" in my last post, it seems the suffix "XL" is only used for the PCI variant, the 3C905. 3com also has internal code names for their cards (or maybe their controller chips). I looked up nicknames from Linux documentation and original 3com Windows INF files. The long names are taken from the official 3Com owners manual.

• ISA: Fast EtherLink (3c515) is nicknamed "Corkscrew"
• PCI: EtherLink III Parallel Tasking 10 Mbps PCI (3c590) and Fast Etherlink Parallel Tasking 10/100BASE... PCI (3c595) are nicknamed "Vortex"
• PCI: EtherLink XL (3c900) and Fast EtherLink XL (3c905) are nicknamed "Boomerang"
• PCI: EtherLink 10 PCI (3c900B) and EtherLink 10/100 PCI (3c905B) are nicknamed "Cyclone"
• PCI: EtherLink 10/100 PCI for Complete PC Management (3c905C) is nicknamed "Tornado"

If there are different variants of the 3c515, all of them are nicknamed "Corkscrew" and all of them use ISA busmaster DMA (but documentation says busmastering can be disabled if it is incompatible with certain PCs). Using a 3c515 without bus mastering likely has no advantage over using a 3c509.

Thanks both

mkarcher wrote on 2025-10-22, 17:22:

Using a 3c515 without bus mastering likely has no advantage over using a 3c509.

Even without bus mastering, the 3C515 is faster than any 10 Mbps card:
Re: Fast Ethernet on ISA

Grzyb wrote on 2025-10-22, 17:40:

mkarcher wrote on 2025-10-22, 17:22:

Using a 3c515 without bus mastering likely has no advantage over using a 3c509.

Even without bus mastering, the 3C515 is faster than any 10 Mbps card:
Re: Fast Ethernet on ISA

Oh, that's nice. Thanks for benchmarking and posting that result. Actually, those rates are comparable to an ISA IDE interface, which makes sense, because I guess both the 3c515 without bus mastering and ISA IDE uses REP INSW/REP OUTSW over the ISA bus.