Motorola MVME2600 manual PCI-ISA Bridge PIB Controller, Disk Drive Controller

3

Functional Description

Disk Drive Controller

The ISASIO device incorporates a PS/2-compatible low- and high-density disk drive controller for use with an optional external disk drive. The drive interfaces with the ISASIO controller via base board connector J4, which relays both power and control signals.

The ISASIO disk drive controller is compatible with the DP8473, 765A, and N82077 devices commonly used to implement floppy disk controllers. Software written for those devices may be used without change to operate the ISASIO controller. The ISASIO device may be used to support any of the following devices:

❏31/2-inch 1.44MB floppy disk drive

❏51/4-inch 1.2MB floppy disk drive

❏Standard 250kbps to 2Mbps tape drive system

Keyboard and Mouse Interface

The National Semiconductor PC87308 ISASIO chip used to implement certain segments of the P2 and front-panel I/O provides ROM-based keyboard and mouse interface control. The front panel of the MVME2603/2604 board has two 6-pin circular DIN connectors for the keyboard and mouse connections.

PCI-ISA Bridge (PIB) Controller

The MVME2603/2604 uses a Winbond W83C553 bridge controller to supply the interface between the PCI local bus and the ISA system I/O bus (diagrammed in Figure 1-1in Chapter 1, Hardware Preparation and Installation).

3-10 Computer Group Literature Center Web Site