They both wear the same Amstrad part number 40031. On the Amstrad chassis schematic diagram, this part is numbered 40030. [https://www.cpcwiki.eu/imgs/4/4a/CPC6128_Schematic.png Source]
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== PAL I/O port ==
Note that no settings are stored in the Gate Array itself regarding the MMR register. But the PAL and Gate Array share an I/O port address so that it appears to be the same chip to the programmer.
Bit14 of the PAL selection address can be at 0 or 1 on CPCs equipped with CRTCs 3, 4.
It must be at 1 on CRTCs 0, 1 and 2 (The result is not guaranteed).
For compatibility reasons, it is strongly advised to always set bit14 to 1 to select PAL.
Furthermore, if bit14=0 then CRTC will be selected too.
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