1. xerox 560 computer system - The UK Mirror Service

the destination byte string begins with the byte locationpointed to by the destination address in register 1 andis C bytes in length. In this case, the source byte is comparedwith each byte of the destination byte string unti I aninequality is found.TBSTRANSLATE BYTE STRING(Immediate displacement, continue after interrupt)TRANSLATE BYTE STRING replaces each byte of the destinationbyte string with a source byte located in a translationtable. The destination byte string begins with the byte locationpointed to by the destination address in regi ster Ru 1,and is C bytes in length. The translation table consists ofup to 256 consecutive byte locations, with the first bytelocation of the table pointed to by the displacement in TBSplus the source address in register R. A source byte is definedas that which is in the byte location pointed to by the19 low-order bits of the sum of the following values.1. The displacement in bit positions 12-31 of the TBSinstruction.Contents of register R+l:The destination byte string begins with the byte locationpointed to by the destination address in register R + 1 andis C bytes in length. The source byte string {translationtable} begins with the byte location pointed to by the displacementin TBS plus the. source address in register R.When the instruction is completed, the destination addressis incremented by C, C is set to zero, and the source addressremains unchanged.Case II, odd R fi e Id {Ru 1 =R}Because of the interruptible nature of TRANSLATE BYTESTRING, the instruction traps with the contents of register Runchanged when an odd-numbered general register is specifiedby the R field of the instruction word.Case III, zero R field {Ru1=1}Contents of register 1:2. The current contents of bit positions 13-31 of register R{source address}.3. The numeric value of the current destination byte, the8-bit contents of the byte location pointed to by thecurrent destination address in bit positions 13-31 ofregister {Ru 1}.The destination byte string begins with the byte locationpointed to by the destination address in register 1 andis C bytes in length. The source byte string {translationtable} begins with the location pointed to by the displacementin TBS. When the instruction is completed, the destinationaddress is incremented by C and C is set to zero.Affected: (DBS), {Ru 1}translated (DBS) -DBSTrap: Instruction exceptionTTBSTRANSLATE AND TEST BYTE STRING{Immediate displacement, continue after interrupt}The R field of the TBS instruction must be an even value forproper operation of the instruction; if the R field of TBS isen odd value, the instruction traps to location X'4D',instruction exception trap.If TBS is indirectly addressed, it is treated as a nonexistentinstruction. The basic processor unconditionally abortsexecution of the instruction (at the time of operation codedecoding) and traps to location X'40' with the contents ofregister R and the destination byte string unchanged.See IITraps By Byte String Instructions" (in this section) forother trap conditions. Note that the check for access trapconditions is done only for the source byte string.Case I, even, nonzero R field (Ru1=R+l)Contents of register R:TRANSLATE AND TEST BYTE STRING compares the maskin bit positions 0-7 of register R with source bytes in a bytetranslation table. The destination byte string begins withthe byte location pointed to by the destination address inregister Rul, and is C bytes in length. The byte translationtable and the translation bytes themselves are identi cal tothat described for the instruction TRANSLATE BYTE STRING.The destination byte string is examined (without beingchanged) unti I a translation byte {source byte} is found thatcontains a 1 in any of the bit positions selected by a 1 inthe mask. When such a translation byte is found, TTBSreplaces the mask with the logical product (AND) of thetransiation byte and the mask, and terminates with CC4set to 1.If the TTBS instruction terminates due to the above condition,the count (C) in register Rul is one greater thanthe number of bytes remaining to be compared and thedestination address in register Rul indicates the location90 Byte-String Instructions