'''Arnold''' was the internal code name of the first Amstrad CPC prototype, which was built around a MOS [[6502]] CPU. As they choosed the Z80 based programming language [[Locomotive BASIC]] as a part of the core system, Amstrad decided to replace the [[6502]] with the Zilog [[Z80]]. One of the "Arnold" prototypes was sold via Ebay in 2005.
== The Gate Array Simulator ==
The [[Gate Array]] was the only component of the Amstrad CPC, which was not a standard one but developed by Amstrad. Before it could be produced as a single chip, they had to make tests with a prototype, wich was a single print on top of the actual motherboard.
<gallery caption="Pictures of the Gate Array prototype">
Image:GA motherboard.JPG|The gate array as a complete additional PCB board
Image:Inside GA.JPG|Another picture of the gate array prototype
</gallery>
== The Grey Amstrad ==