Modbo 5.0 modchip for Playstation 2 is a variant of Modbo 4.0 with added DEV3 mode. The DEV3 mode allows homebrew to be loaded directly from USB stick or hard drive. Please note that any modchip for PS2 will allow for tools like USBAdvance to load games from USB hard drive, the only difference here is that you don't need memory stick or internal hard drive to store the loader itself. This modchip supports PS2/PStwo consoles between V5-V18, use Modbo 4.0 diagrams. The Modbo 5.0 is not a successor of Modbo 4.0, it is designed by another team who just took the name to gain market advantage.
NOTE: Tools for Modbo 5.0 can be found here.