SN54LS28
QUAD 2-INPUT NOR BUFFER (Motorola)
SN54LS28
QUADRUPLE 2-INPUT POSITIVE-NOR BUFFER (Texas Instruments)
SN54LS280
9-BIT ODD/EVEN PARITY GENERATORS/CHECKERS (Motorola)
SN54LS280
9-BIT ODD/EVEN PARITY GENERATORS/CHECKERS (Texas Instruments)
SN54LS283
4-BIT BINARY FULL ADDER (Motorola Inc)
SN54LS283J
4-Bit Binary Full Adders (Texas Instruments)
SN54LS20
DUAL 4-INPUT NAND GATE (Motorola Inc)
SN54LS20
Dual 4-Input Positive-NAND Gate (Texas Instruments)
SN54LS21
DUAL 4-INPUT AND GATE (Motorola Inc)
SN54LS21
DUAL 4-INPUT POSITIVE-AND GATE (Texas Instruments)