Kahenraz wrote on 2021-10-02, 20:01:

I ran into this while browsing. This buy has a box full of them.

Is there any reason to choose an ATA33 controller over an ATA133? The only thing I can think of is that this one mentions support for OS/2 Warp and SCO Unix.

Having better backward compatibility is perhaps an advantage in itself despite it being 'merely' ATA33.
I don't know if ATA33 in itself has any advantages over ATA133 except maybe for the compatibility. And you don't need to use the 80-wired IDE cables for whatever that is worth.

I've never seen a controller enforce 80 pin cables a requirement. It should either fallback to ATA33 or provide an option to select a slower speed.

Please don‘t post any ebay links. We‘ve had a user causing a lot of problems who wrote posts like this. And yes, this rule is not always followed but I try.

I think I found what the OP was talking about?

Looks like they are Highpoint HPT343 cards.

Kinda overpriced IMO.

I think it's reasonable if you want the box for display or are willing to pay a little extra to know that it hasn't be floating in a box of parts where it may have been damaged.

IDE controllers are valuable upgrades for specific use cases which is why I shared it. But I also asked about ATA33 specifically since I don't collect parts this old in general and have no frame of reference.

I looked at the post briefly but could not see what was important to me, lack of the ISA paddle. I have a few older PCI ATA IDE cards and they have a mini "ISA paddle" that also takes up the back end of ISA slot for the high IRQ's/addresses as well as the main card in PCI slot to be compliant with older boards-BIOS. As for ATA33 those types are designed for motherboard without any IDE on board AFAIK..

Have these got a BIOS onboard? If so, they might be nice for boards with BIOS disk size limitations...

Are there any IDE controllers that don't have an onboard BIOS?

ISA, definitely. PCI, I'm not sure. I think it's not a guarantee that they're bootable.

How does an ISA controller work without a BIOS? Is it something that gets loaded into memory at runtime or is it meant as a physical interface for additional channels not available on the motherboard?

Same way a SATA controller works without a BIOS. You boot Windows off some other (bootable) media and the driver loads, and you get access to your drives on that controller. I think most SATA cards have BIOSes though.

ISA IDE controllers without a BIOS work similarly, like the (tertiary) IDE controllers on sound cards, meant for CD-ROM drives. Your CD-ROM driver loads and finds the drive on the correct port and with the correct IRQ. This is also pretty much how a BIOS-less secondary controller works in a system that only has primary IDE on the mainboard. I have a BIOSless ISA IDE card in one of my 486s for this, it's comprised of pretty much all glue logic since it's not super complicated to adapt ISA to IDE.

Interesting, I've never seen such a card with "ISA paddle"

https://richelectronics.co.uk/product/tekram- … -sockets-mba008