Although in general ISA devices are excluded from PC 98, many PC 98 systems will include ISA support that allows users to insert ISA add-on devices. This section summarizes the basic requirements for a PC system that includes the ISA bus. In PC 97, ISA was required to be implemented with full support for Plug and Play ISA boot devices.
In addition to ISA expansion cards, the following are also ISA devices:
Any such devices located at I/O addresses below 100h can use fixed resources and are exempt from Plug and Play requirements for unique IDs, flexible resource configuration, and dynamic disable capabilities.
1. System supports Plug and Play ISA specification and Plug and Play BIOS
| Required |
If ISA support is included in a PC 98 system, the manufacturer must implement the standards described in the following Plug and Play specifications:
The Plug and Play specifications are available at http://www.microsoft.com/hwdev/specs/pnpspecs.htm. Additional ISA clarifications and white papers related to ISA Plug and Play under the Microsoft Windows operating system are available at http://www.microsoft.com/hwdev/busbios/.
Note: Standard system devices are excluded from this requirement. The system can reserve static resources for devices such as interrupt controllers 1 and 2, timer (8254-2), keyboard controller (8042), real-time clock, DMA page registers, DMA controllers 1 and 2, and math coprocessor (if present). For a system based on Intel Architecture, these fixed resources are located at I/O addresses below 100H and can also include an NMI mask.