Relay computers - OR functionality - symbology

[Patrick/VCM SysOp]

> Why didn't they use * or X for AND then?

The period is a convenient substitution for a dot that was used in math to
indicate multiplication (the "real" symbol is usually represented as more
vertically centered within the character cell).  I have some books that also
use "x", but that character is again a more (or sometimes less) stylized
glyph than the simple upper- or lowercase "X".

By the way, that plus (or) symbol in those same books is often a plus inside
a circle.  So I suspect the use of plain-old-plus is again a convenient
substitution into ASCII.

Patrick