420C21

Found on...

• Last Fortress
• Pang Pom's
• Sky Alert

Notes

NOTE FROM Twistedsymphony:
It also seems that Metro often did factory conversions and reprogrammed PALs.
the original 420C21 and 420D23 were from PangPom's
When converting PangPom's to Sky Alert they covered up the white line on the PLD with a black marker, and when converting to Last Fortress they covered up the white line on the IC with a black marker AND also covered the white dot with a red marker (I've included photos of this).
Some later versions of Last Fortress used unique PLD labels with a "420F" prefix but they appear to be functionally identical.