Pack (Pack) - RCA 70/46 Reference Manual

Pack
(PACK)
General Description
Format
(55)
Condition Code
Interrupt Action
Notes
Decitnal Arithmetic
Instructions
• The operand specified by the second address (B:/D
2 )
is converted from
zoned format to packed format and the result is placed in the location
specified by the first address (Bt/D
1 ) .
The operand specified by the second address must be in zoned format.
The sign is obtained from the zone portion of the rightmost byte of the
second operand and is placed in the rightmost four bits of the first operand
(result field). All other zones are ignored. The four-bit numeric portions
(stripping the four-bit zone) of each byte are then placed adjacent to the
sign, and to each other, to fill the result field.
The result is extended with high-order zeros if the second operand field
is shorter than the first. If the first operand field is not large enough to
contain all the significant digits from the second operand field, the remaining
digits are ignored. The operands may overlap.
F2
o
7 8 11 12 15 16 19 20 31 32 35 36
47
• Unchanged.
• Address error:
Addressing.
Protection.
• 1. Signs and digits are not checked for validity.
2. The second operand is not changed except when the operands overlap.
3. Processing is from right to left, one byte at a time.
164