You can download it if you know where to look. Try:
ftp://207.46.133.140/bussys/sql/public/fixes/usa/SQL65/Sp3/
Select your processor (Alpha or Intel) and continue drilling down.
Assuming an Intel processor, your full download path is:
ftp://207.46.133.140/bussys/sql/public/fixes/usa/SQL65/Sp3/Sp3Intel/65SP3X86.EXE