Description: A bit array where the presence of a particular bit indicates
a failure of a particular Power On Self Test (POST).

Each octet within the value of this object specifies a set
of 8 POST tests, with the first octet specifying tests
1 through 8, the second octet specifying tests 9
through 16, etc.   Within each octet, the most significant
bit represents the lowest numbered test, and the least
significant bit represents the highest numbered test. Thus,
each test is represented by a single bit within the value of
this object. If that bit has a value of '1' then that test
has failed; the test has passed if its bit has a value of
'0'.

The defined POST tests are:

Number   POST Test
------   ---------
   1     Supervisor RAM
   2     EIA/TIA-232 console port
   3     Ethernet address
   4     Timer interrupt
   5     Real time clock
   6     Non-volatile RAM
   7     Port loopback

Default value: string of length 0.