If you want a 775 setup for some retro action, you will want one with an Intel 865 or Via PT880 Pro chipset as there are drivers available for Win9x.

If you want AGP for video, then the boards I have seen are limited to DDR1.

If you want PCI-e for video, they are available with DDR2 support.

Examples:
AGP/DDR1
https://www.newegg.com/Product/Product.aspx?I … N82E16813157338

PCIe/DDR2
https://www.ebay.com/itm/Intel-Micro-ATX-LGA7 … U-/152934269427

ASRock also made a 775 board that has both AGP and PCI-e support as well as DDR1 and DDR2 support. PCI-e is limited to x4 though
https://www.asrock.com/mb/VIA/775Dual-vsta/index.asp

And if you don't care if you have support for Win9x, then look for a board with the Intel P45 chipset which is the best chipset ever made for LGA775.

It really depends on what OS and what GPU you want to use. You want to use Win 98, or Win XP is good enough? GPU - want to use some older AGP card, or more modern PCI-e?

Pretty much whole PC would be build around your OS of choice. Tell us this, and we can help you with parts.

cyclone3d wrote:

ASRock also made a 775 board that has both AGP and PCI-e support as well as DDR1 and DDR2 support. PCI-e is limited to x4 though.

On one side you are right, but on the other, this really doesn't matter with cards, which could be used in that system (since you can use only PCI-e cards up to PCI-e version 2.1).

If I were to build a socket 775 system I would first decide it the system was to be painless and optimal performance/compatibility or if it was a build for more fun.

If for the former, do not think about anything than the later intel chipsets (P35, P45, X38)

If you want to have fun, then go for one of the earliest that only supported Pentium 4 and Pentium D, maybe even throw in Nvidia chipset for early SLI support! Mocking around with the Asrock stuff is just a pain in my experience, but if you want a challenge then go for it 😀