I burned the ISO image of FD64 9.00 Alpha to a USB flash drive. Then I tried to boot my legacy-BIOS-enabled PC, whose memory size is 4 GB, from that flash drive. After selecting "Fatdog64 without savefile" from boot menu, I got "Not enough memory to load specified image" error message on the screen several seconds later.
By the way, My PC does boot up successfully with FD64 9.00 "broken" version dated 2023-July-07, whose ISO image is available in https://distro.ibiblio.org/fatdog/broken/900tip/ .