Why doesn't my object code/machine code contain 1's and 0's
This is a result of the program that opened the file. 

All files on the system are in binary. What matters is how you interpret it.

The editor you used has displayed the digits in their common form:

"UH...." is the equivalent hexadecimal "5548...."  which is binary "101010101001000...."

Thus you need a Hex or Binary editing program to 'view' the '1's and '0's.