According to the manual, AOpen AP5TC is a rare Socket 7 motherboard (i430TX) with an SB-Link header.

There appears to be solder pads for SB-Link on the Intel D850EMV2. Its the right configuration of pins and given its proximity to the ICH2, I'm inclined to think its PC/PCI.

Just did a build with that mobo. Bios update appears through windows only.

ShovelKnight wrote on 2020-04-05, 14:42:

According to the manual, AOpen AP5TC is a rare Socket 7 motherboard (i430TX) with an SB-Link header.

I must be special then. Came up on that board in a motherboard lot. Yes your right it indeed does have sb-link. Almost feels kinda useless when it has isa slots already. Either way its a interesting board i hope can work with a 266 Tillamook.

2 more boards:
Legend QDI PlatiniX 4 (i850) (PGA423)
Gigabyte GA-6VXE7+ (693A) (PGA370)

I have recently acquired a new retro rig with the Abit ZM6 motherboard and can confirm that it has a working SB-Link header. This motherboard is based on the Intel 440ZX chipset (socket 370).

Just tested it with my Yamaha YMF724 and SB-Link worked perfectly.

What does the SB-Link do for us?

Velociraptor wrote on 2020-06-27, 17:31:

What does the SB-Link do for us?

Connecting a PCI sound card to the motherboard using SB-Link improves its compatibility with DOS games.

Broadly speaking, PCI sound cards use either SB-Link, DDMA or a TSR program to function under DOS. In terms of compatibility, SB-Link tends to give the best results followed closely by DDMA. Compatibility using a TSR program can be hit or miss, varying largely between games.

Aha! I'd googled it before but hadn't found a nice clear explanation like that. Thanks!

Intel D850GB (their original Pentium 4 board, and the only one they made for Socket 423) has a soldered PC/PCI header.

zoinknoise wrote on 2021-08-18, 00:39:

Intel D850GB (their original Pentium 4 board, and the only one they made for Socket 423) has a soldered PC/PCI header.

The variant without the onboard sound has this. Just looked at some pictures.

HP Compaq Deskpro EN Desktop PC P1.0GHz SFF (Intel 815E) - on PCI riser there is some Audio connector...might it be SB-LINK? In BIOS there is PCI SERR and PCI bus mastering. IRQ 5 is for onboard audio or used for your PCI sound card. I have ESS 1938S, which runs only in TDMA mode and this causes random hangs and card not being detected. Need something without EMM386 for Carmageddon 3dfx Voodoo 3 😒. In Windows 98 SE it works, but crashes randomly in the middle of some level (game rank 74).

I am interested in this topic. I have not found much information online about how it actually works. Can you have SB link without any ISA support? (Some boards from this era have unsoldered ISA slots.)

Joakim wrote on 2021-10-23, 15:53:

I am interested in this topic. I have not found much information online about how it actually works. Can you have SB link without any ISA support? (Some boards from this era have unsoldered ISA slots.)

Yes. The important thing is that the chipset and memory controller supports everything necessary for ISA-style DMA. In fact, I'd say that the sideband signals that are on the PC/PCI connector were more commonly used to support DMA on PCI-to-ISA bridge chips on industrial motherboards. This is why this subject always winds up drifting to late Intel 8xx chipset series boards. Those were the last boards that will ever support ISA DMA and, by extension, PC/PCI.

As you mention industrial motherboards, was it used for other things than sound cards?

Joakim wrote on 2021-10-23, 18:02:

As you mention industrial motherboards, was it used for other things than sound cards?

The actual header and cable weren't, to my knowledge. The sideband signals that PC/PCI uses were also used to connect to PCI-to-ISA bridge chips built onto many industrial motherboards so they could properly support DMA. Most of the ISA cards used with these industrial motherboards were interface cards for various kinds of sensors, or to control a piece of machinery. I vaguely remember that CnC mills and routers and such were stuck with old tech for many years. I don't know of a specific example that needed ISA DMA to work, but I'm sure they existed if this was deemed a necessary feature.

Maybe I will ask around at work just out of interest. We have some machines from the 80s wher the programs are still run from floppys.. they probably run DOS.

MSI MS-6117 or LX6
slot 1 based on i440LX
https://theretroweb.com/hardware/motherboards/msi-lx6

Still would be nice to have this as a list in the wiki?

ABIT BE6-ii has sb-link as well.

ECS P6IPAT i815 with Tualatin support. I think I'll test it next week with a SV550/Yamaha 724F-V