Various representations of hebrew characters in TeX

There are two seperate systems of Hebrew fonts: 7 bit fonts and 8 bit fonts, sometimes referred to as Old Code and New Code, respectively.

In Old Code, each character is represented internally by 7 bits. this is an older system, but it is still much used. In this representation, only 128 characters are possible. Hence, Hebrew characters have to take the place regularly occupied by other characters; they take the place of the lower case English characters (except Aleph, which takes the place of an apostroph).

In New Code, each characters is represented internally by 8 bits. This makes for 256 different characters, and the Hebrew characters appear side by side with English characters.

IBM PCs use 8 bits fonts, but there the Hebrew characters are located in different locations then has been chosed for New Code; This has to be taken into consideration when moving TeX's sources from PC to UNIX or to VMS and/or back. The Hebrew PC fonts are sometimes referred to as PC Code.