OP = 41
AF is the length of the A field. A value of 00 is equal to
a length of 100 units (digits or characters as specified by the
A address controller). AF may be indirect or may indicate that the
A syllable is a literal.
BF is the eight-bit selection mask. One bits in this mask select those bit positions to be tested for one bits within each eight-bit group of the A data field. A through F may be used to specify undigits in the mask. The field will not be recognized as indirect.
The A Syllable is the address of the data field to be examined. Address may be indexed, indirect or extended. The final address controller data type must be UN or UA. Use of SN data type is will cause an Illegal Instruction (IEX = 03) fault. See Compatibility Notes A.05.
The Bit One Test instruction tests a data field in memory A in eight-bit groups, for one bits in the bit positions selected by the field mask BF.
If the number of digits accessed is even, the entire eight-bit mask is applied to successive groups of two digits. if the number of digits is odd, the operation is the same until the last digit is accessed. The most significant four bits of the mask are applied to this digit.
Set the Comparison Flags to EQUAL if any tested bit is one or to HIGH if all tested bits are zero bits.
Field overlap is not applicable to this instruction.
|41||03F0||A Field (UN)|
BEFORE AFTER A Field 001 unchanged MASK F0F
Comparison Flags nn EQUAL
|41||0203||A Field (UA)|
BEFORE AFTER A Field C4C4 unchanged MASK 0303
Comparison Flags nn HIGH