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A bus is the hardware used to connect peripheral devices to the computer. SVR5 and SCO OpenServer 5 support a number of industry-standard buses with different performance levels. Various bus standards are compared below.
Bus type Clock speed Bus width Bus speed (Mhz) (Mhz) (bits) (MB/sec) ------------------------------------------------------ ISA-8 8 8 5 (continuous) ISA-16 8 16 10 (continuous) EISA 8 32 32 (burst) MCA 10 32 40 (burst) PCI 33 32 132 (continuous) VESA 33 32 132 (continuous)
Use the facilities discussed in ``Autoconfiguration'' to detect and configure devices on any supported bus type. SCO SVR5 1 and 2 and SVR5 support bus-independent APIs for access to for this purpose. bus-dependent configuration space. Specifically:
On SCO OpenServer 5, separate functions are defined for accessing each supported bus type. These include:
Because a system can have a PCI bus in combination with any other bus type, driver writers must use both functions in drivers that support both PCI and non-PCI cards.