IBM 610 Manual Of Operation

Also see for 610: Technical overview and introduction

BASIC ARITHMETIC OPERATIONS 11One-Place Shifts(Shift Right One Place)The depression of this key tells the machine to shiftthe contents of the selected register to the right oneplace. The point moves with the digits, and the regis-ter shifted remains selected. This operation may begiven several times in succession. For instance, SR SR SRwill cause the contents of the selected register to bemoved to the right three places. In using this instruc-tion on auto-point numbers, care must be taken thatthe number is returned to the right-hand standard(point in the middle) before other operations are car-ried out on it; otherwise, errors will result.Example:24 SRRegisterBefore 24+000621053162181 .2560000000000000After 24+000062105316218 1.25600000000000024 SelectedWhen a positive number is shifted to the right ina register, the vacated high-order positions of theupper half of the register are automatically filled withzeros.When a negative number is shifted to the right ina register, the vacated high-order positions of the up-per half of the register are automatically filled withnines.SL HShift Left One Place)The depression of this key tells the machine to shiftthe contents of the selected register to the left oneplace. The point moves with the digits, and the regis-ter remains selected. This operation may be givenseveral times in succession. Care must be taken thatauto-point numbers shifted away from the right-handstandard position with this instruction are returnedbefore the number is used again in an arithmetic op-eration.Example:25 SLRegisterBefore 25 + 000000067142187 .2180000000000000After 25+00000067142187.2 18000000000000002 5 SelectedWhen a number is shifted to the left in a register,the vacated low-order positions of the lower half ofthe register are automatically filled with zeros.Multiple-Place ShiftsThere are two additional shifting operations. Theoperations they cause will be according to whetherthe 610 is in the auto-point or the fixed point mode:SL15) (Shift Left 15, Auto-Point)The depression of this key tells the machine to shiftthe contents of the selected register to the left untilone of the following conditions is satisfied:1. The most significant (non-zero) digit is nextto the sign position.2. The decimal point is next to the sign position.3. A maximum shift of 15 places has been made.A shift of exactly fifteen places is not implied bythis instruction when the 610 is in the auto-pointmode.Example 1:auto-point26 SL 15RegisterBefore 26+000010620151843 .2146000000000000After 26+10620151843.2146 000000000000000026 SelectedExample 2:auto-point30 SL 15RegisterBefore 30+000000000000000 .0076511821750000After 30+. 007651182175000 000000000000000030 SelectedReminder: In the auto-point -mode, if a numberis positioned in a register in such a way that no zerosappear to the left of the high-order significant digit,OR if a number is positioned with the decimal pointin the high-order position of the register, the numberis said to be in the left-hand standard position.The operation of the machine as a result of thedepression of the SL 15 and SR 15 keys is differentin the case of the fixed-point mode.