The pack/unpack functions don't work correctly for pre-1925 provisional designations (see here)
To distinguish these from the (messy) "old-style" scheme (which is not in use any more), they begin with an 'A', rather than 1. Quoting from the MPC page:
This scheme has been extended to pre-1925 discoveries--such designations are indicated by the replacement of the initial digit of the year by the letter `A'. Thus, A904 OA is the first object designated that was discovered in the second half of July 1904.
So for example 442 Eichsfeldia is A899 CA, rather then 1899 CA. Likewise unpacking I99C0A should return A899 CA and not 1899 CA.
The current (buggy) behavior is in the screenshot.
The pack/unpack functions don't work correctly for pre-1925 provisional designations (see here)
To distinguish these from the (messy) "old-style" scheme (which is not in use any more), they begin with an 'A', rather than 1. Quoting from the MPC page:
So for example 442 Eichsfeldia is
A899 CA, rather then1899 CA. Likewise unpackingI99C0Ashould returnA899 CAand not1899 CA.The current (buggy) behavior is in the screenshot.