True BASIC

True BASIC is a fully structured variant of the BASIC programming language descended from Dartmouth BASIC – the original BASIC – invented by college professors John G. Kemeny and Thomas E. Kurtz.

When True BASIC appeared on the market, initially based on Dartmouth BASIC 7 -- otherwise known as ANSI BASIC -- it implemented a number of new features over QBASIC, and allowed the user a 16 color (redefinable), 640×480 backdrop for programming. True BASIC introduced new functions for graphics primitives like plot, plot area, flood, etc. It also was the first to provide a method for saving a portion of the screen and blitting it elsewhere, but had no proper buffering implementation.

There are versions for DOS, Windows, MacOS, and Linux systems.

LET M = 2
LET X = 3
LET B = 4
LET Y = M * X + B
PRINT "Y="; Y
END