Viking Interworks 32-Bit Cardbus CF Compact Flash PCMCIA PC card adapter/reader for Compaq DELL HP SONY Toshiba Notebook Laptop MacBook with PCMCIA slot, not Expresscard. Requirement: Windows98/98SE/2000/ME/XP, Mac OS X Tiger (10.4.x). and Mac OS X (10.2.8 to 10.3.9) CardBus cards are able to take advantage of internal bus speeds that can be as much as four-to-six times faster than 16-bit PC Cards 4-6 Times Faster Than Standard 16-Bit Adapters. CardBus is a high-performance 32-bit version of the PC Card standard. For CF type one/two and MicroDrive.