Fairchild
From a photo of a real pre-NTI Apple-1.
7451 PC F, black plastic.
7537 date code.
Total # on board: 1.
Signetics
From a photo of a real NTI Apple-1.
Vertical labeling, black plastic, block “S” logo, additional S below part number.
Total # on board: 1.
Fairchild
7451 PC F, black plastic, 7623 date code. On my Mimeo replica.
Fairchild
9N51/7451 PCF, black plastic. 7349 date code.
Signetics
Vertical labeling, black plastic, block “S” logo, no added S. 7645 date code.
Signetics
Vertical labeling, black plastic, block “S” logo, no added S. 7342 date code, almost exact date code match to the real Apple-1.