multiply-2048-v.0.2

Supports multiplication of two base-10 integer inputs of at least 310 digits which is suitable for multiplying 1024-bit numbers in base-10.
You can also multiply directly in binary, or base-3, 4, 5, 6, 7, 8 and 9. (Experimental).

Theoretically supports up to 2.1 billion digits of integer output, 2.1 billion digits of combined integer input, if you have a computer fast enough.
Not yet tested on inputs larger than 2^1024 or outputs larger than 2^2048.

Returns the exact integer result.
Uses strings to carry and calculate digit by digit.
Powershell only supports up to uint64, anyways.
That is a mere 18446744073709551616.
Base-10 as in Base Ten.
Otherwise any base would be Base-10 in its own base.

multiply-512-v.0.1

Multiplies two 256-bit Base-10 integers

Supports up to 155 digits of decimal output, 78 digits of decimal input, which is sufficient to input 256-bit binary numbers in base-10.

Not yet tested on inputs larger than 115792089237316195423570985008687907853269984665640564039457584007913129639936.

Maximum output is 999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999.

Returns the exact integer result.
Uses strings to carry and calculate digit by digit.
Powershell only supports up to uint64, anyways. 
That is a mere 18446744073709551616. 
Base-10 as in Base Ten. 
Otherwise any base would be Base-10 in its own base.