* Printer Port Data and Strobe
* Floppy Motor enable [[flip-flop]], Floppy Address decoding (FDC chip Select)
The ASIC has a configuration resistor (R128) distinguishing between 128K and 64K mainboards. It disables the PAL component on the 464 Plus and GX4000. [https://www.cpcwiki.eu/forum/news-events/announcing-sonic-gx-a-new-episode-of-sonic-the-hedgehog-for-amstrad-gx-4000/msg248436/#msg248436 Source]
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