There is a limited character set available with this punched card format. It's capitals only I'm afraid and if you happen to use a character that's currently not convertible - it'll be replaced with a space.
Note that alphanumeric characters were standard for almost all coding systems. Other characters that are almost universally coded using the same pattern are: -.$, . From there on, it depended on the computer being used and what was being coded. Some programming languages required specialist characters that were not in normal use while others omitted many of the extra characters all together.
The system used here is known as the Hollerith system and was quite an early format not necessarily designed with electronic computers in mind so has more human readable punctuation marks than you'd expect to see in early computer cards.
Punched cards did not have a new line character. You would create a new punched card, or set of cards for each line of your text/code. This is how the new line is treated in this emulation.
Characters available using the Hollerith code are:
&-0123456789 ABCDEFGHIJKLMNOPQR/STUVWXYZ ¢.<(+|!$*);¬,%_>?:#@'="