If you were hoping this would be easy, the bad news is that there simply isnβt a simple and easy way to do this - the text cursor is not something you can just change with just a few lines of javascript or CSS.
If you really want to do this, you will need to write your own text input system in javascript - display the cursor yourself, wait for the keys to be pressed, print them on the screen, process something like a word-wrap manually ... this is a fair job.
Fortunately, others have already done this work and made it available for sharing, so I suggest that your best starting point is to look at some existing examples and see how they did it.
Here I found with a quick search: http://terminal.jcubic.pl/ . There are many others that you could try, though.
Hope this helps.
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