I would imagine all socket 7 boards support two floppy drives, all on the same cable. Support for more than one started to be removed in P4 systems and later.

Any requirement on downclock CPU and disable caches? If you want to do it through software you have much more control with an AMD K6-II+ or III+ mobile based CPU instead of a Pentium. Phil on Youtube have some good videos on this subject.

vetz wrote on 2021-02-21, 19:01:

I would imagine all socket 7 boards support two floppy drives, all on the same cable. Support for more than one started to be removed in P4 systems and later.

Here for example [ https://www.gigabyte.com/il/Motherboard/GA-586HX/sp#sp ] is written:

"I/O Controller
...
1x Floppy port (360KB-2.88MB)
..."

Doesn't it mean that only one FDD attachment is available ? Or that means that there is 1 port available for 2 drives to be attached to it ?

Any requirement on downclock CPU and disable caches? If you want to do it through software you have much more control with an AMD K6-II+ or III+ mobile based CPU instead of a Pentium. Phil on Youtube have some good videos on this subject.

Regarding Phil's videos, in his "Building the 3 in 1 DOS Retro Gaming PC - 386 486 and Pentium" video, if I remember correctly, he used Pentium 133 mhz CPU instead.

I have never seen a socket 7 machine without support for two FDDs, but I do have a Slot 1 board that only supports one floppy

Second floppy physically doesn't work even when driving the FDC directly, not a BIOS limitation

Ok, so my suspicions were unfounded.

Those DOS retro PCs are such a headache.

For months was looking for external 5.25" FDD via LPT to attach it to my Thinkpad just to find out that the only real option is MicroSolutions Backpack drives, which are rare as a Yeti and expensive as a whole PC unit with 5.25" drive in it. And even if you did manage to get it somehow, guess what? You can't boot from it. 😀

So now I'm planning to build a desktop just to be able to use 5.25" drive ... Life is pain.

Thank you all for your advices.

ThinkpadIL wrote on 2021-02-21, 19:11:

Doesn't it mean that only one FDD attachment is available ? Or that means that there is 1 port available for 2 drives to be attached to it ?

1 port for 2 floppy drives. As stated in many ASUS socket 7 motherboard manuals:

Supports two drives of either 5.25-inch (360KB or 1.2MB) or 3.5-inch (720KB,. 1.44MB, or 2.88MB) disk drives

ThinkpadIL wrote on 2021-02-21, 19:11:

Regarding Phil's videos, in his "Building the 3 in 1 DOS Retro Gaming PC - 386 486 and Pentium" video, if I remember correctly, he used Pentium 133 mhz CPU instead.

The video I had in mind was the Building a 4 in 1 Retro Gaming PC video featuring a AMD K6-III+ and the SetMul and K6SPEED utilities. The benefit with these utilities is that you get better speed control than just using L1 and L2 cache on the Pentium (which can be controlled using CpuSpd - A Hardware Based CPU Speed Control Utility for DOS/Win9X Retro Gaming). The drawback is that such a system is alot more expensive to aquire than just using a regular Pentium.

vetz wrote on 2021-02-21, 20:02:

The video I had in mind was the Building a 4 in 1 Retro Gaming PC video featuring a AMD K6-III+ and the SetMul and K6SPEED utilities. The benefit with these utilities is that you get better speed control than just using L1 and L2 cache on the Pentium (which can be controlled using CpuSpd - A Hardware Based CPU Speed Control Utility for DOS/Win9X Retro Gaming). The drawback is that such a system is alot more expensive to aquire than just using a regular Pentium.

I see. Thank you for this useful information. Phil has a great channel and he makes great videos with plenty valuable details.

But at this stage I see no point in investing a fortune in a retro PC. Maybe I'm wrong, but for me building a retro machine at the lowest possible price is a part of a retro fun. Diamonds are forever ... but old hardware is not. It's only a matter of time till those components will die and there will be no replacement available. But of course I may change my mind in the future. 😀

Thank you one more time.