Int 13H [PC] Function 12H (18) Controller RAM diagnostic

Causes the fixed disk adapter to carry out a built-in diagnostic test on its internal sector buffer, indicating whether the test was passed by the returned status.

Call with:

AH = 12H

Returns:

If function successful

Carry flag = clear

If function unsuccessful

Carry flag = set

AH = status (see Int 13H Function 01H)

Note:

This function is supported on PC/XT fixed disks only.