The 82378ZB System I/O (SIO) and 82379AB System I/O APIC (SIO.A) components are PCI-to-ISA Bus Bridge devices. These devices integrate many of the common I/O functions found in today's ISA-based PC systemsa seven channel DMA controller, two 82C59 interrupt controllers, an 8254 timer/counter, a BIOS timer, Intel SMM power management support, and logic for NMI generation. In addition, the SIO and SIO.A each support a total of six PCI Masters, and four PCI Interrupts. Decode is provided for peripheral devices such as the flash BIOS, real time clock, keyboard/mouse controller, floppy controller, two serial ports, one parallel port, and IDE hard disk drive.