MCPX

2025-10-23T11:56:50Z

Slim Dread: MCPX abbreviation (taken from xboxdevwiki.net/The_Hidden_Boot_Code_of_the_Xbox#Why_a_Hidden_ROM_is_Needed)

The MCPX (Media and Communications Processor for Xbox) is the southbridge chip of the Xbox chipset made by Nvidia. It contains the sound processors ([[APU]] and [[ACI]]) as well as the USB, PCI, IDE, etc, controllers [https://web.archive.org/web/20010418214256/http://www.ga-hardware.com:80/preview.cfm?id=NVIDIAMCP], [https://web.archive.org/web/20010410003338/http://www.nvnews.net/previews/mcpx/mcpx.shtml].

Dolby Laboratories anounced in April 2001, The xbox will feature a new "Dolby Interactive Content Encoder" of which the Xbox is the first console to get this.[https://web.archive.org/web/20010419091049/http://www.codejunkies.com:80/Xbox/news.asp?id=9422][https://www.ign.com/articles/2001/04/16/xbox-to-feature-dolby-digital-51-surround-sound-in-games]
== ROM ==

The MCPX is home to the secret [[MCPX ROM]].

== Pin L21: PC Speaker ==

The MCPX has a PC Speaker pin which can be controlled using [https://wiki.osdev.org/PC_Speaker the standard PC Speaker interface].
However, no actual speaker is connected to the pin, so while the signal exists, there will be no audible sound on a stock Xbox.

A speaker can be soldered to this pin in order to make the signal audible [https://www.youtube.com/watch?v=Te4MSskbBEE][https://github.com/0DaveX/beep/]

The original Microsoft code does not drive the PC Speaker at all, so this otherwise unused pin can also be used for inaudible forms of unidirectional communication.

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== See Also ==
* [[NForce]]
* [http://siliconpr0n.org/archive/doku.php?id=azonenberg:nvidia:mcpx Die Inspection]

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MCPX