[Falkon1313]

Maybe FreeBASIC would be useful, (although it's a compiler rather than an interpreter, and a more modern dialect than 70s BASIC, mostly compatible with QBASIC/QuickBASIC). https://www.freebasic.net/

It handles 64-bit doubles: https://www.freebasic.net/wiki/wikka.php?wakka=KeyPgDouble