1 Initiating Unit 2 Cycling Unit 3, 4 Master Programmer, panels 1, 2 5 Accumulator 1 6 Accumulator 2 7 Accumulator 3 8 Accumulator 4 (Quotient) 9 Divider-Square-Rooter 10 Accumulator 5 (Numerator I) 11 Accumulator 6 (Numerator II) 12 Accumulator 7 (Denominator—Square Root I) 13 Accumulator 8 (Denominator—Square Root II) 14 Accumulator 9 (Shift I) 15 Accumulator 10 (Shift II) 16 Blank panel for new unit (Converter) 17 Accumulator 11 (Multiplier) 18 Accumulator 12 (Multiplicand) 19-21 Multiplier, panels 1, 2, 3 22 Accumulator 13 (Left-Hand Partial Products I) 23 Accumulator 14 (Left-Hand Partial Products II) 24 Accumulator 15 (Right-Hand Products I) 25 Accumulator 16 (Right-Hand Products II) 26 Blank panel for new unit (100 Registers) 27 Accumulator 17 28 Accumulator 18 29 Accumulator 19 30 Accumulator 20 31, 32 Function Table 1, panels 1, 2 33, 34 Function Table 2, panels 1, 2 35, 36 Function Table 3, panels 1, 2 37-39 Constant Transmitter, panels 1, 2, 3 40-42 Printer, panels 1, 2, 3 43-45 Portable Function Tables _A_, _B_, and _C_ 46 IBM Card Reader 47 IBM Summary Punch _Note_: The accumulators from which a number can be sent to the printer are now accumulators 1, 2, and 15 to 20. In reading over the table, we find a number of words that need explaining. Some of the explanation we can give in the summary of the units of Eniac: SUMMARY OF UNITS OF ENIAC QUANTITY DEVICE SIGNIFICANCE 20 Accumulators Store, add, and subtract numbers 1 Multiplier Multiplies 1 Divider-Square-Rooter Divides, and obtains twice the _square root_ of a number (see Supplement 2) 3 Function Tables Part of the memory, for referring to tables of numbers 1 Constant Transmitter Stores numbers from the card reader and from hand-set switches 1 Printer Punches machine results into cards 1 Cycling Unit Controls the timing of the various parts of the machine 1 Initiating Unit Has controls for starting a calculation, for clearing, etc. 1 Master Programmer Holds the chief controls for coordinating the various parts of the machine