What would we do without them?
+---+--+---+ D7 |1 +--+ 24| VCC D6 |2 23| D8 D5 |3 22| D9 D4 |4 21| D10 D3 |5 20| D11 D2 |6 74 19| D12 D1 |7 150 18| D13 D0 |8 17| D14 /EN |9 16| D15 /Y |10 15| S0 S3 |11 14| S1 GND |12 13| S2 +----------+
+---+--+---+ D3 |1 +--+ 16| VCC D2 |2 15| D4 D1 |3 14| D5 D0 |4 74 13| D6 Y |5 151 12| D7 /Y |6 11| S0 /EN |7 10| S1 GND |8 9| S2 +----------+
+---+--+---+ A4 |1 +--+ 14| VCC A3 |2 13| A5 A2 |3 74 12| A6 A1 |4 152 11| A7 A0 |5 10| S0 /Y |6 9| S1 GND |7 8| S1 +----------+
+---+--+---+ /1EN |1 +--+ 16| VCC S1 |2 15| /2EN 1A3 |3 14| S0 1A2 |4 74 13| 2A3 1A1 |5 153 12| 2A2 1A0 |6 11| 2A1 1Y |7 10| 2A0 GND |8 9| 2Y +----------+
+---+--+---+ /Y0 |1 +--+ 24| VCC /Y1 |2 23| S0 /Y2 |3 22| S1 /Y3 |4 21| S2 /Y4 |5 20| S3 /Y5 |6 74 19| /EN2 /Y6 |7 154 18| /EN1 /Y7 |8 17| /Y15 /Y8 |9 16| /Y14 /Y9 |10 15| /Y13 /Y10 |11 14| /Y12 GND |12 13| /Y11 +----------+
+---+--+---+ 1EN1 |1 +--+ 16| VCC /1EN2 |2 15| /2EN1 S1 |3 14| /2EN2 /1Y3 |4 74 13| S0 /1Y2 |5 155 12| /2Y3 /1Y1 |6 11| /2Y2 /1Y0 |7 10| /2Y1 GND |8 9| /2Y0 +----------+
+---+--+---+ 1EN1 |1 +--+ 16| VCC /1EN2 |2 15| /2EN1 S1 |3 14| /2EN2 /1Y3 |4 74 13| S0 /1Y2 |5 156 12| /2Y3 /1Y1 |6 11| /2Y2 /1Y0 |7 10| /2Y1 GND |8 9| /2Y0 +----------+
+---+--+---+ S |1 +--+ 16| VCC 1A0 |2 15| /EN 1A1 |3 14| 4A0 1Y |4 74 13| 4A1 2A0 |5 157 12| 4Y 2A1 |6 11| 3A0 2Y |7 10| 3A1 GND |8 9| 3Y +----------+
+---+--+---+ S |1 +--+ 16| VCC 1A0 |2 15| /EN 1A1 |3 14| 4A0 /1Y |4 74 13| 4A1 2A0 |5 158 12| /4Y 2A1 |6 11| 3A0 /2Y |7 10| 3A1 GND |8 9| /3Y +----------+
+---+--+---+ /Y0 |1 +--+ 24| VCC /Y1 |2 23| S0 /Y2 |3 22| S1 /Y3 |4 21| S2 /Y4 |5 20| S3 /Y5 |6 74 19| /EN2 /Y6 |7 159 18| /EN1 /Y7 |8 17| /Y15 /Y8 |9 16| /Y14 /Y9 |10 15| /Y13 /Y10 |11 14| /Y12 GND |12 13| /Y11 +----------+
+---+--+---+ /RST |1 +--+ 16| VCC CLK |2 15| RCO P0 |3 14| Q0 P1 |4 74 13| Q1 P2 |5 160 12| Q2 P3 |6 11| Q3 ENP |7 10| ENT GND |8 9| /LOAD +----------+
+---+--+---+ /RST |1 +--+ 16| VCC CLK |2 15| RCO P0 |3 14| Q0 P1 |4 74 13| Q1 P2 |5 161 12| Q2 P3 |6 11| Q3 ENP |7 10| ENT GND |8 9| /LOAD +----------+
+---+--+---+ /RST |1 +--+ 16| VCC CLK |2 15| RCO P0 |3 14| Q0 P1 |4 74 13| Q1 P2 |5 162 12| Q2 P3 |6 11| Q3 ENP |7 10| ENT GND |8 9| /LOAD +----------+
+---+--+---+ /RST |1 +--+ 16| VCC CLK |2 15| RCO P0 |3 14| Q0 P1 |4 74 13| Q1 P2 |5 163 12| Q2 P3 |6 11| Q3 ENP |7 10| ENT GND |8 9| /LOAD +----------+
+---+--+---+ D |1 +--+ 14| VCC E |2 13| Q7 Q0 |3 74 12| Q6 Q1 |4 164 11| Q5 Q2 |5 10| Q4 Q3 |6 9| /RST GND |7 8| CLK +----------+
+---+--+---+ SH//LD |1 +--+ 16| VCC CLK1 |2 15| CLK2 P4 |3 14| P3 P5 |4 74 13| P2 P6 |5 165 12| P1 P7 |6 11| P0 /Q7 |7 10| D GND |8 9| Q7 +----------+
+---+--+---+ D |1 +--+ 16| VCC P0 |2 15| SH//LD P1 |3 14| P7 P2 |4 74 13| Q7 P3 |5 166 12| P6 CLK1 |6 11| P5 CLK2 |7 10| P4 GND |8 9| /RST +----------+
+---+--+---+ |1 +--+ 16| VCC B2 |2 15| B1 B3 |3 14| B0 SET-9 |4 74 13| RST Z |5 167 12| U/CAS Y |6 11| ENin ENout |7 10| STRB GND |8 9| CLK +----------+
+---+--+---+ U//D |1 +--+ 16| VCC CLK |2 15| /RCO P0 |3 14| Q0 P1 |4 74 13| Q1 P2 |5 168 12| Q2 P3 |6 11| Q3 /ENP |7 10| /ENT GND |8 9| /LOAD +----------+
+---+--+---+ U//D |1 +--+ 16| VCC CLK |2 15| /RCO P0 |3 14| Q0 P1 |4 74 13| Q1 P2 |5 169 12| Q2 P3 |6 11| Q3 /ENP |7 10| /ENT GND |8 9| /LOAD +----------+
+---+--+---+ D2 |1 +--+ 16| VCC D3 |2 15| D1 D4 |3 14| WA0 RA1 |4 74 13| WA1 RA0 |5 170 12| /WR Q4 |6 11| /RD Q3 |7 10| Q1 GND |8 9| Q2 +----------+
+---+--+---+ /OE1 |1 +--+ 16| VCC /OE2 |2 15| RST Q0 |3 14| D0 Q1 |4 74 13| D1 Q2 |5 173 12| D2 Q3 |6 11| D3 CLK |7 10| /CLKEN1 GND |8 9| /CLKEN2 +----------+
+---+--+---+ +----+---+---*---+ /RST |1 +--+ 16| VCC |/RST|CLK| D | Q | Q0 |2 15| Q6 +====+===+===*===+ D0 |3 14| D5 | 0 | X | X | 0 | D1 |4 74 13| D4 | 1 | / | 0 | 0 | Q1 |5 174 12| Q4 | 1 | / | 1 | 1 | D2 |6 11| D3 | 1 |!/ | X | - | Q2 |7 10| Q3 +----+---+---*---+ GND |8 9| CLK +----------+
+---+--+---+ +----+---+---*---+---+ /RST |1 +--+ 16| VCC |/RST|CLK| D | Q |/Q | Q1 |2 15| Q4 +====+===+===*===+===+ /Q1 |3 14| /Q4 | 0 | X | X | 0 | 1 | D1 |4 74 13| D4 | 1 | / | 0 | 0 | 1 | D2 |5 175 12| D3 | 1 | / | 1 | 1 | 0 | /Q2 |6 11| /Q3 | 1 |!/ | X | - | - | Q2 |7 10| Q3 +----+---+---*---+---+ GND |8 9| CLK +----------+
+---+--+---+ A0 |1 +--+ 14| VCC A1 |2 13| A7 CASE |3 74 12| A6 CASO |4 180 11| A5 EVEN |5 10| A4 ODD |6 9| A3 GND |7 8| A2 +----------+
+---+--+---+ /B0 |1 +--+ 24| VCC /A0 |2 23| /A1 S3 |3 22| /B1 S2 |4 21| /A2 S1 |5 20| /B2 S0 |6 74 19| /A3 CIN |7 181 18| /B3 M |8 17| /G /F0 |9 16| COUT /F1 |10 15| /P /F2 |11 14| A=B GND |12 13| /F3 +----------+
+---+--+---+ /G1 |1 +--+ 16| VCC /P1 |2 15| /P2 /G0 |3 14| /G2 /P0 |4 74 13| Cn /G3 |5 182 12| Cn+X /P3 |6 11| Cn+Y /P |7 10| /G GND |8 9| Cn+Z +----------+
+---+--+---+ +---+---+---*---+---+ 1A |1 +--+ 14| VCC | CI| A | B | S | CO| |2 13| 2A +===+===+===*===+===+ 1B |3 74 12| 2B | 0 | 0 | 0 | 0 | 0 | 1CI |4 183 11| 2CI | 0 | 0 | 1 | 1 | 0 | 1CO |5 10| 2CO | 0 | 1 | 0 | 1 | 0 | 1S |6 9| | 0 | 1 | 1 | 0 | 1 | GND |7 8| 2S | 1 | 0 | 0 | 1 | 0 | +----------+ | 1 | 0 | 1 | 0 | 1 | | 1 | 1 | 0 | 0 | 1 | | 1 | 1 | 1 | 1 | 1 | +---+---+---*---+---+
+---+--+---+ P1 |1 +--+ 16| VCC Q1 |2 15| P0 Q0 |3 14| CLK /CLKEN |4 74 13| /RCLK D//U |5 190 12| /RCO Q2 |6 11| /LOAD Q3 |7 10| P2 GND |8 9| P3 +----------+
+---+--+---+ P1 |1 +--+ 16| VCC Q1 |2 15| P0 Q0 |3 14| CLK /CLKEN |4 74 13| /RCLK D//U |5 191 12| /RCO Q2 |6 11| /LOAD Q3 |7 10| P2 GND |8 9| P3 +----------+
+---+--+---+ P1 |1 +--+ 16| VCC Q1 |2 15| P0 Q0 |3 14| RST DOWN |4 74 13| /BORROW UP |5 192 12| /CARRY Q2 |6 11| /LOAD Q3 |7 10| P2 GND |8 9| P3 +----------+
+---+--+---+ P1 |1 +--+ 16| VCC Q1 |2 15| P0 Q0 |3 14| RST DOWN |4 74 13| /BORROW UP |5 193 12| /CARRY Q2 |6 11| /LOAD Q3 |7 10| P2 GND |8 9| P3 +----------+
+---+--+---+ +---+---*---------------+ /RST |1 +--+ 16| VCC | S1| S0| Function | D |2 15| Q0 +===+===*===============+ P0 |3 14| Q1 | 0 | 0 | Hold | P1 |4 40194 13| Q2 | 0 | 1 | Shift right | P2 |5 74194 12| Q3 | 1 | 0 | Shift left | P3 |6 11| CLK | 1 | 1 | Parallel load | L |7 10| S1 +---+---*---------------+ GND |8 9| S0 +----------+
+---+--+---+ /RST |1 +--+ 16| VCC J |2 15| Q0 /K |3 14| Q1 P0 |4 74 13| Q2 P1 |5 195 12| Q3 P2 |6 11| /Q3 P3 |7 10| CLK GND |8 9| SH//LD +----------+
+---+--+---+ /LOAD |1 +--+ 14| VCC Q2 |2 13| /RST P2 |3 74 12| Q3 P0 |4 196 11| P3 Q0 |5 10| P1 /CLK1 |6 9| Q1 GND |7 8| /CLK0 +----------+
+---+--+---+ /LOAD |1 +--+ 14| VCC Q2 |2 13| /RST P2 |3 74 12| Q3 P0 |4 197 11| P3 Q0 |5 10| P1 /CLK1 |6 9| Q1 GND |7 8| /CLK0 +----------+
+---+--+---+ S0 |1 +--+ 24| VCC D |2 23| S1 P0 |3 22| Q7 Y0 |4 21| P7 P1 |5 20| Y7 Y1 |6 74 19| P6 P2 |7 198 18| Y6 Y2 |8 17| P5 P3 |9 16| Y5 Y3 |10 15| P4 CLK |11 14| Y4 GND |12 13| /RST +----------+