# Overview

This section lists the requirements for incorporating extended joystick support in titles development, and compares the features of various versions of the extended joystick. Topics include:

- Requirements
- Features of the Extended Joystick
- Bit Order

## Requirements

Requirements for incorporating extended joystick support in titles development include:

- Extended joystick
- Extended joystick driver (included in the Portfolio OS)
- 3DO Development Station

## Features of the Extended Joystick

The three-axis, extended joystick manufactured by CH Products offers the following features:

- One four-way switch
- Three single buttons
- One fire button
- One z-axis (throttle) control
- Movement capability (x and y)
- Trim controls (x and y)
- Left shift
- Right shift
- Play/pause
- Stop

The table below provides a description of the features available on various versions of the extended joystick:

    Table 1:   Joystick versions and features.
    --------------------------------------------------------
    Feature          |Description
    --------------------------------------------------------
    4 single buttons |Includes one fire button in the index
                     |finger position,and three additional
                     |buttons (A, B, and C) on the extended
                     |joystick handle.
    --------------------------------------------------------
    4Ðway switch     |Located in thumb position. The consumer
                     |extended joystick comes with a single
                     |4-way switch, or 4 single buttons
                     |placed in a diamond pattern.
    --------------------------------------------------------
    x and y axis     |Consumer versions of the extended
    movement         |joystick are permitted a maximum of
                     |10-bit precision in each direction.
                     |8-bit precision is the minimum allowed.
    --------------------------------------------------------
    Auxiliary axis   |Consumer versions of the extended
    control          |joystick are permitted a maximum of
                     |10-bit precision in each direction.
                     |8-bit precision is the minimum allowed.
    --------------------------------------------------------
    Left-shift,      |These features are implemented with
    right-shift,     |single buttons mounted on the base of
    stop, play/pause |the extended joystick.
    --------------------------------------------------------

Figure 1 shows the placement of controls on the extended joystick.

Figure 1: Extended joystick controls.

## Bit Order

When 8-bit precision is used, the two least-significant bits are padded with zeros to fill all 10 bits available, as shown in Figure 2.

Figure 2: Bit layout for 8-bit precision.