Introduction

This chapter describes how multifunction devices get installed and configured by the Windows® 95 Plug and Play architecture. Multifunction devices are physical devices which incorporate multiple logical devices. For example a board incorporating a SCSI controller and a sound chip is considered a multifunction device, a DSP board that can behave as a modem, a sound device or both is considered a multifunction device as well.

The following devices/scenarios are covered:

• PNP - Multiple logical devices on a single board consuming non-overlapping resources. (Resources refers to use of IRQs, I/O ranges, memory ranges, or DMA channels.)
• PNP - Multiple logical devices on a single board consuming overlapping resources
• PNP - Multiple devices incorporated in a parent/daughter card configuration
• PNP - Multiple devices incorporated in a master/slave configuration via a proprietary bus
• PNP - A multi-personality board (eg. a DSP with multiple functions but only one available at a time)
• Legacy multifunction devices

This chapter assumes the reader is familiar with the Windows 95 Plug and Play architecture and the relevant chapters in the Windows 95 Device Driver Development Kit (DDK). One of the most important aspects of installing and configuring a multifunction card is having a proper INF file. The Beta 2 INF format has been extended to support the different flavors of multifunction cards. Sample INF files are included in this document.