In the famous words of an old Mathcad user Yosemite Sam : "I paid my four bits to see the high-diving act and I'm a-gonna see the high-diving act. UGH ITS NOT HERE IT! DAM WHERE IS IT?
We seek it here, we seek it there,
Those Mathcad users seek it everywhere.
Is it in heaven? — Is it in hell?
That damned, elusive Mathcad Prime 4 - PTC can go to Hell.
No, no, no,
You must wait, wait and then wait a little more, until the Himmelhochjauchzing introductory notice from PTC arrives that tells that their unsurpassed new version of Prime is out, before you can expect to download it.
The latest I heard was February 13th, but I would not hold your breath. It still will not have the features I need, basic plotting. It has been promised in Prime 5.0.