Why is the default right-hand text limit for editor set at 75?

Why is the default right-hand text limit for Matlab's editor at 75? Isn't the convention for code and other ASCII formats typically at 80? I understand that this can be changed in the settings. I just want to know why Mathworks decided for the default to be at 75.

[DGM]

Despite the fact that I don't know of anywhere else 75 CPL is common, it's a number that tends to come up a lot.

From Robert Bringhurst's The Elements of Typographic Style:

"Anything from 45 to 75 characters is widely-regarded as a satisfactory length of line for a single-column page set in a serifed text face in a text size."

Other references cite similar numbers, the bottom end hovering around 35-50 and the top end often right arount 75 CPL.

... of course, most of these style guides have nothing to do with code on a computer screen, regardless of how many times people suggest that the column widths used by newspapers are univerally optimal for readability and have nothing to do with easing the task of page layout with the necessity for image and advertisement insertion.

In the end, I have no idea why it's 75. If it came from MATLAB's foundations in Fortran or Java, you'd expect it to be higher. Maybe 75 columns is the usable width of an old display with a post-it note obscuring the edge of the screen.

[Matthew Fall]

Interesting response, thanks! Also, hilarious comment at the end!

[Star Strider]

It’s been several decades since I typed FORTRAN code onto 80-column punchcards and fed them to a room-sized mainframe that was less powerful than my current wristwatch, however if I remember correctly, there were 72 usable columns on each punchcard. The first eight columns were for a comment column (1) and the other 7 for number lines (for code that was longer than one card), and other non-code information. Later FORTRAN screen editors kept that standard.