First post, by koverhbarc
I promised I'd start this thread and here we go. What's the best way to get ISA support on a P4 machine? I hope people aren't keeping this some sort of secret.
The Intel 8xx chipsets, of course, support DMA through an external PCI/ISA bridge, perhaps the only chipsets that do. In almost all cases I've seen that is provided on the motherboard, so we're talking about ones with ISA slot(s) and working DMA. This could include the 815 chipset (P3, perhaps the best, supports all, but ISA examples may be hard to find), 845 (most common but doesn't have 200/800 FSB), and finally 865/875 (ideal choice). The last is also available in Socket LGA775 and thus can theoretically support later processors but as gaming only cares about one core, it's best to stick with the P4.
I only see them for public listing on eBay, but the choice is pretty terrible and I'm not sure if I can trust motherboard sellers (from experience among other things). Does anyone get them directly from industrial distributors? If so, which do sell to individuals and for what sort of price?
The motherboard 'ANOVO AIMB-865' has just been mentioned twice here (Problems regarding ANOVO AIMB-865 and LGA 775 Motherboards with AGP Slots) and can only be found from those sources; further, the first suggests there's some fiddly bits to get it working properly. So with the MB-865, of which it's probably a variation. Those are both LGA775, I guess I'd rather have Socket 478 for which I already have CPUs but they, actually, are cheap; either will do.
Another feature I'd consider essential for DOS gaming is support for a real PC speaker, not just an on-board beeper, but that's never mentioned in descriptions and I'd assume industrial boards are least likely to have it.
If one must use an 845 board, will later P4s (with 200 FSB) actually work in it, though underclocked? This would be good to know. I would think they should, but Intel may have added something to stop that being done and I've never heard of it for the P4 specifically. Has anyone tried putting a P4 in a lower FSB than specified?
Finally the PCI/ISA bridge need not be on-board. The chipset doesn't care, actually - so a bridge that plugs into a PCI slot would work with 8xx chipsets to provide ISA sound support. These seem impossible to find, though a Russian guy has two videos on YouTube showing this being done (with a Core 2!). There's one 865 motherboard still being sold new for $50 (presumably not new production - I assume Intel's long discontinued the 8xx chips.) and if an adapter would give it ISA that's a reasonable option.