7420
Dual 4-Input NAND Gates (Fairchild Semiconductor)
7420
Dual 4-Input Positive NAND Gate (NTE)
7421
Dual 4-Input Positive AND Gate (Fairchild Semiconductor)
74221
Dual non-retriggerable monostable multivibrator (NXP)
74221
Dual Non-Retriggerable Monostable Multivibrator (Fairchild Semiconductor)
74221
Dual Monostable Multivibrators (Hitachi Semiconductor)
7423
Dual 4-Input NOR Gate (Texas Instruments)
74240
Octal 3-STATE Buffer/Line Driver/Line Receiver (Fairchild Semiconductor)
74240
Eight three-state inverting buffer / line driver / line receiver (San Mao)
74244
Octal 3-STATE Buffer/Line Driver/Line Receiver (Fairchild Semiconductor)