HP Mobo Slot 1 supports 233Mhz to 333Mhz PentiumII (Celeron 433?) 3- banks of SIMMS (72 pin) (6 slots total) On-board Primary and secondary IDE (floppy as well) HP proprietary power supply required (and or rewire AT power supply) 4- PCI 4- EISA (On riser card that attaches to mobo) Intel PCIset 440FX 2- USB ports 2- PS2 ports 2- Serial ports 1- parallel port There is also a chip on the board that I don't recognize the company logo.