Keyboard Port and Peripheral Requirements

The primary input component for a PC is the keyboard. An 8042 microcontroller or its equivalent has traditionally controlled the keyboard connection on the system board. However, USB connections and wireless connections are important design considerations for PC 98 keyboards. Also, these design requirements do not exclude (but do not encourage) implementing a legacy AT-style keyboard port.

This section summarizes the specific PC 98 hardware feature requirements for keyboard ports and peripherals. Some keyboard port requirements differ, depending on the type of port being used.

The PC 98 general device requirements are defined in the “System Requirements for I/O Ports and Devices” section earlier in this chapter, including the requirements for a device ID, automated software-only settings for device configuration, device drivers and Windows-based installation, and icons for external connectors.

For requirements that apply if wireless capabilities are provided for the keyboard, see the “Wireless Component Requirements” section later in this chapter.

22. Keyboard connection meets requirements for its bus class

Required

These requirements depend on the type of connection designed into the system and ensure that all Plug and Play requirements are met and that Microsoft drivers support this device.

If a PS/2-style keyboard port is used, it must meet the following requirements:

Support IRQ 1 on Intel Architecture to ensure the proper functioning of software written for legacy systems, which expect to use this IRQ signal

Map the I/O address ports to 60h and 64h

Return expected scan codes, including send ID (0F2h) and response ACK (0FAh), plus 2-byte ID
If a USB connection is used, it must meet the following requirements:

USB Specification, Version 1.0 or higher

USB Human Interface Device Class Specifications, Version 1.0 or higher

Minidriver support based on WDM HID class support in the operating system

If a USB keyboard is the sole keyboard implementation in an Intel Architecture system, it must support the USB Boot Device specification. The system BIOS must provide boot support as specified in the “Basic PC 98” chapter in Part 2 of this guide and as defined in Universal Serial Bus PC Legacy Compatibility Specification, Version 0.9 or higher.

23. No interference occurs between multiple keyboards

Required

For example, when a mobile PC is connected to a docking station, more than one keyboard can be attached to the system simultaneously. The keyboard ports on a mobile PC and a docking station must be able to resolve conflicts between the two ports when the mobile unit is docked. Windows supports multiple configurations through the registry and will determine which keyboard to enable.

For more information about managing resources and devices for a mobile PC/docking station combination, see the “Mobile PC 98” chapter in Part 2 of this guide.

24. Keyboard includes Windows and Application logo keys

Recommended

The following are requirements for a keyboard design that includes any Windows logo keys:

The keyboard must be developed according to technical requirements in New Key Support for Microsoft Windows Operating Systems and Applications.

The keyboard must be compatible at the Windows virtual key-code level.

The keyboard must pass the requirements in the Windows logo key testing software.

The Windows logo key must function as a modifier (ctrl, shift, or alt).

The Windows Flag trademark must be clearly distinguished on the key top according to the guidelines provided in New Key Support for Microsoft Windows Operating Systems and Applications.
The following are recommendations for a keyboard design that includes any Windows logo keys:

Both left and right Windows logo keys are not required in order to offer full functionality under the Windows operating system.

The Application key can be a dual-function key and can be used to replace the fn key. In this case, a single press-and-release action sends the scan code for the Application key, and holding this key down while pressing another key will modify it to perform the fn function.
Given the crowded nature of compact keyboards on mobile PCs and keyboards that support double-byte characters (such as Japanese-language keyboards), it might be difficult to add three new keys. For mobile PCs, minimal implementation of new keys includes the addition of one Windows logo key and one Application key.