INT 2F U - Smart Prompt - INSTALLATION CHECK
        AX = C64Ch
        BX = 5553h
Return: AX = 4CC6h if installed
        BX = 5355h if installed
Program: Smart Prompt (SMARTPMT) is a freeware TSR by Steve Gibson which forces
          an immediate flush of SmartDrive's (and compatible caches') buffers
          on returning to the DOS prompt

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