New "Quadron v1.20.tap" file uploaded that contains some minor tweaks:

    * improved sensitivity of weapon 1 lasers ("Beam Laser")
    * overall performance optimisations
    * fixed bug where background scenery could become corrupted
    * fixed potential bug in attract mode
    * now uses ROM-based IM2 interrupt vector table to reclaim RAM for above modifications - WARNING! This game is now definitely a 48K only game!

An associated "Quadron v1.20.sna" snapshot file is also included for completeness.