After googling for about an hour, I have to confess, that while I find a lot of documentation about functions operating on bit arrays, I cannot find a single reference on how to actually create a bit array.
Right now, it seems to me that either, some arrays with other element types can be handled as bit arrays OR that one could use (make-array :element-type (???)) where I could not find any explanation as to what to put where I wrote the "???".
So, while it is probably obvious to anyone else, I have no idea how to create a bit array. I know about how to write a literal bit array - but if I need a bit array with, say 2^16 bits - how would I do it?
You are right about using make-array, just use 'bit as the element type. Try
(make-array initial-size :element-type 'bit).
The symbol BIT names the bit type and could be replaced with any other type specifier to make an array holding objects of that type. In this example initial-size is just a variable holding a whole number.