The CPC6128 second bank of 64K RAM is controlled by a PAL 16L8 chip Programmable Array Logic (not PAL). Not to be confused with PAL, the colour encoding system for analog televisions). The CPC6128 second bank of 64K RAM is controlled by a PAL 16L8 chip. It has the Amstrad part number 40031.
On the CPC 6128 schematic, it is top centre: [http://www.cpcwiki.eu/imgs/4/4a/CPC6128_Schematic.png CPC6128 Schematic] however the X inputs aren't distinguished.
