The NDEV (RVT-001 on NDEV 2.x units, RVD on NDEV 1.x units) is a fully-fledged development kit for the Wii. It does not have a disc drive or internal hard drive, so all software is read from NAND or the host system. The NDEV cannot boot without an attached host system, and can only launch disc titles if they are given to the NDEV through an optical disc emulator on the host system. The NDEV thus, uses a special system menu that is designed for purposes of debugging and development. The NDEV could operate in two distinct modes: one mode which simulates a disc's read speed and another, a turbo mode, that reads data as quickly as possible, shortening the potential wait times during a test. This allows developers to cut down testing times, while also ensuring that their games were optimized enough to cut down on loading times through an actual disc.
Development on the NDEV is done firstly using the Revolution SDK supplied by Nintendo, which creates a file with the .elf extension. This file is then thrown through a sequence of applications which burn the game into a disc image that can be then loaded into the devkit using a command. Such an image can also be loaded onto an RVT disc, a special variant of the Wii Disc that can be read by the Wii and launched on development kits such as the RVT-R Reader. These development kits did not have the same development functionalities as the NDEV, but allowed for writing errors and launching non-retail games. They served a useful purpose for testers, who didn't need the programming functions offered by the significantly more expensive NDEV. The NDEV can, however, directly read .elf files without needing to burn them into a disc image beforehand through the "ndrun" command in the Revolution SDK to launch the optical disc emulator to create a simulated optical disc image. This runs the associated .elf directly from a filesystem on the host PC.
Compared to regular hardware, the NDEV features all the ports found on a retail system. The NDEV has a mains power switch on the back, and an actual power switch located on the front of the unit. All GameCube controller ports, SD reader, and GameCube memory card ports have been moved up to the front of the unit. There is also a dipswitch located on the front, which could be used for debugging purposes. For example, toggling processor usage UI. Also on the front lies multi-purpose LED display, activity diodes for the console's components, a power button with a diode, as well as reset, sync and eject buttons. Eject is likely intended to emulate a console ejecting a disc. There is also a button with labelled reserved. This button seemingly never served any type of function. On the back of the NDEV, there are two USB Type A ports as found on a retail systems, however, there is also three USB Type B ports not seen on retail systems. One of these is labeled as a debug port, used for collecting the debug output of games running. One is labeled as COM, used to send commands to the unit. Finally, one is labeled DI. There is also one serial (DB9) 115200-baud port. In order to use the devkit, there needs to be at least three USB cables plugged into the same computer; one as a software link, another as a data link, and also another for debugging. The instruction manual of the NDEV also states that there needs to be a serial cable plugged in, but that's just optional and the system will launch without it.
Unlike the Wii, the NDEV has a built-in power supply, whereas retail models have an externally placed power supply. The NDEV's GDDR3 RAM (MEM2) is upgraded from 64MB to 128MB, giving it a total of 192MB of RAM, up from the retail Wii's 88MB total.
The NDEV's menu is very simplistic in design. When the system first boots, it prompts the user to insert a disc into the system. It prompts the user to press Z on the Nunchuk to open the system menu of the system. From here, the user can configure the default parameters: the date and time of the internal clock, sound mode, screen settings, language, controller settings including vibration as well as sensor bar config and speaker volume, and parental control. There is also a firmware screen that lets the user view the firmware details. There is also a save data utility, devkit settings with region config, system information, and finally an option to format the system's memory.
The NDEV 1.x units were the first NDEV units that have seen usage during February 2006 to around June 2006 for internal usage and (potentially limited) third-party game development. Internal documentation refers to version 2 of the NDEV as the 'main system for game developers' with NDEV 1.x being a bare board intended only for internal usage in Nintendo, but it is known that some 1.x NDEV units and their associated Revolution SDK (1.0) were briefly distributed to third-party developers. It is also known that there were also enclosed NDEV 1.x units.
NDEV 1.x had a number of features not present in 2.0 units and later, including, but not limited to:
- Variable clock frequency for Broadway & Hollywood (controlled with DIP switches or an external clock connected over BNC)
- JTAG ports for Broadway & Hollywood
- Additional power supply testing features
- 2 external SD slots in addition to the internal Wi-Fi SDIO slot (all versions of IOS support having 2 external SD slots, but it is unclear if this feature was meant for the final product)
- Wii and GameCube drive ports
Some NDEV 1.x units also included Hollywood chips with blank eFuses. It is unknown what the exact difference between the NDEV 1.x revisions (known to be NDEV 1.0, 1.1, and 1.2) are, but it is most likely just the revisions to the Hollywood processor.
NDEV 2.0 includes mostly-final hardware seen on retail units, aside from a few minor bugs as well as the inclusion of four wired Wii Remote controller ports via coaxial cables. The production 2.1 decreases this to only one port. The initial release of the 2.0 did not include wireless controller support, but the "2.01(ES)" revision added it. On 2.x units, there is a BT mode switch, which allows developers to switch from using wireless controllers to using wired controllers, through the coaxial cables. Pre-production NDEV 2.1 units also exist. These units are known to have a different serial number sticker on the back as well as having four wired controller ports like the 2.0. One such unit is known to have a port for WiFi over RF, but it is unknown if this applies to every unit as the sticker contains a checkbox for if this feature is included or not.
The NDEV 2.1 is the most common and effectively final revision of the NDEV.