Missing DMA support?

gdjacobs wrote:

Missing DMA support?

Probably, if VIA dropped ISA support, it might dropped PC/PCI and ISA DMA as well

Intel still supoorted it on ICH southbridges since the original ICH all the way to ICH5 acording to this datasheet
http://www.intel.com/assets/pdf/whitepaper/318244.pdf

Starting with ICH6 and 6300ESB (Server variant of ICH5), Intel dropped support for PC/PCI DMA which was necesary to provide DMA under PCI/ISA Bridges. Consequently, ISA slots on newer VIA plataforms, Intel chipsets with ICH6+ and later SiS chipsets won't support DMA and, begin limited into slave ISA slots

I remember running a Genius SoundMaker value on the matsonic KT266, and it worked fine. It was one of those weird SDR/DDR combo boards. The sound card ran fine, but I could not get a SCSI card to work (I needed it for an expensive scanner). The SCSI card only had an external connector for the scanner, no HDD or FDD.

kanecvr wrote:

I've had two KT266 boards with ISA - one made by matsonic, and one made by epox (I think). The thing is I'm not sure it's fully functional ISA - I think it used a PCI to ISA bridge...

kanecvr, can you recall please what models with KT266 and ISA? I don't know at least one. I know the only motherboard with [soc-A+DDR+ISA+AGP] BIOSTAR M7MIA. It has north AMD-760 and south VIA686B.

gdjacobs wrote:

Missing DMA support?

Carlos S. M. wrote:

Probably, if VIA dropped ISA support, it might dropped PCI/PCI and ISA DMA as well

No!
VIA VT8233, 8235, 8237 are all supporting DMA through PCI bus. I checked this in pure DOS with SB Live! not once.

Carlos S. M. wrote:

The majority of GV/GV mobos didn't even have AGP/PCI-E slot at all

And no again. This slot which you call "AGP" was solved on many many i845GV boards and wasn't really AGP bus. It intended for Intel DVI out adapters.

PARUS wrote:

kanecvr, can you recall please what models with KT266 and ISA? I don't know at least one. I know the only motherboard with [soc- […]
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kanecvr wrote:

I've had two KT266 boards with ISA - one made by matsonic, and one made by epox (I think). The thing is I'm not sure it's fully functional ISA - I think it used a PCI to ISA bridge...

kanecvr, can you recall please what models with KT266 and ISA? I don't know at least one. I know the only motherboard with [soc-A+DDR+ISA+AGP] BIOSTAR M7MIA. It has north AMD-760 and south VIA686B.

gdjacobs wrote:

Missing DMA support?

Carlos S. M. wrote:

Probably, if VIA dropped ISA support, it might dropped PCI/PCI and ISA DMA as well

No!
VIA VT8233, 8235, 8237 are all supporting DMA through PCI bus. I checked this in pure DOS with SB Live! not once.

ignore my mistake on my quote, i meant the PC/PCI DMA used for SB-Link and allow PCI to ISA Bridges to support DMA on ISA, i'm talking about DMA on ISA slots, not PCI

All Epox boards i can find with google, have no ISA slots:

KT266
EP-8KHA - NO ISA

KT266A - VT8233
EP-8KHA+ - NO ISA
EP-8KHAL - NO ISA
EP-8KHM - ???

KT266A - VT8233A
EP-8KHA3 - NO ISA
EP-8KHAL+ - NO ISA

KT266A - VT8235
8K2AI - ???
EP-8K2A - ???
EP-8K2AI - ???

For matsonic socket A KT266 chipset, i can really find nothing what looks like a KT266 board with ISA from matsonic.
Also these matsonic's with KM266 have no ISA:

MS8157E - MATSONIC - NO ISA
MS8158D - MATSONIC - NO ISA
MS8158E - MATSONIC - ???

http://www.motherboard.cz/matsonic.htm

Carlos S. M., if southbridge has not ISA bus support in default how can it have ISA DMA support? Of course it absent.

By the way fully functional ISA can be even on board with not ISA support by southbridge because Winbond and ITE bridges are a nice absolutely clear for all signal lines. If a mobo (chipset+bios) is still having fully Legacy IRQ and DMA for PCI bus (and fully IO range 0210-E680) be sure you can get fully functional ISA on such board.

Matsonic boards don't really have consistent model numbers... If I remember correctly I had a Matsonic K266+ or something like that. It was printed on a sticker slapped on the board.