Drop in replacement for EPM3064ALC44-10

Look at the Atmel/Microchip ATF1504ASV-15JU44. It is a direct drop in for the EPM3064ALC44.

You can use the Microchip POF2JED tool to convert your Altera .pof file to the .jed program file to program the part.

It is rated at 15ns speed grade vs 10ns for Altera but you will have to evaluate its timing in your application.

The Atmel/Microchip part is still in production and available at major distributors (Mouser, DigiKey, etc).

Altera/Intel no longer has any equivalent parts to the MAX EPM3K or EPM7K series in production.

Any solution from Altera/Intel will require a redesign of your board.