Translate And Test (Trt) - RCA 70/46 Reference Manual

Translate and Test
(TRT)
General Description
Format
(55)
Condition Code
Interrupt Action
Notes
Logical
Instructions
• The variable length operand, which is specified by the first address
(BdD
1 ) ,
is used as the argument (byte-by-byte) to reference a list (func-
tions) specified by the second address (B
2
/D
2 ) .
The functions referenced
are inspected for zero or non-zero. If a non-zero is encountered, the address
of the argument byte is loaded into General Register 1 (General Register
13 in P
a ;
General Register 9 in P
4)
and the function byte is loaded into the
rightmost end of General Register 2 (General Register 14 in P
3 ;
General
Register 10 in P
4).
Whenever zeros are encountered in the function list,
the operation proceeds to the next byte. The first operand is unaltered.
The bytes of the first operand are termed the argument bytes. Processing
of the first operand is from left-to-right, one byte at a time. Each argument
byte is added to the second operand, which is the starting location of the
translate table. This sum, in turn, addresses a byte location within the
table, which is termed a function byte. Then, the function byte retrieved
from the table is inspected for all zeros.
If the function byte is all zeros, the operation proceeds to the next
argument byte and continues processing. If the function byte is not all
zeros, the instruction inserts the address of the argument byte in the low-
order 24 bits of General Register 1 (13 or
9)
and inserts the retrieved
non-zero function byte in the low-order eight-bits of General Register 2
(14 or 10). The high-order eight bits of General Register 1 (13 or
9)
and high-order 24 bits of General Register 2 (14 or 10) are unaltered.
The operation terminates when a (non-zero) function byte is accessed
or when the first operand field is exhausted.
DD
L
o
7 8 15 16 19 20 31 32 35 36
47
• 0 - accessed function bytes all zeros.
1 - a non-zero function byte is encountered before the first operand
field is exhausted.
2 - the last function byte is non-zero.
3-not used.
• Address error:
Addressing.
• 1. The variable length field specified by the first address is unaltered.
2. If non-zero functions do not occur, General Registers 1 (13 or
9)
and
2 (14 or 10) are unaltered.
3. The first operand and the translation table are addressed by their
leftmost bytes.
4. The length of the table, in general,,) must be 256 bytes, unless the
domain of argument bytes is limited to a specific subset by the
program and data.
5. The L field specifies the length of the first operand minus one.
6. This instruction is useful for scanning input streams and locating
delimiters for variable length records and fields.
7. In processor states PI and P
2,
General Registers 1 and 2 are used.
In processor state
P3'
General Registers 13 and 14 are used. In
processor state P
4,
General Registers 9 and 10 are used.
183