The Tektronix 7B81P is a programmable time base plug-in for 7000-series scopes that was probably designed in 1975.
It is composed of a digital board, a trigger board, and a sweep board. On the digital board, there is a Motorola 6800 microprocessor and six 6820 Peripheral Interface Adapter ICs to provide more I/O pins. On the trigger board, there is a 155-0126-00, a 155-0109-00, two AD7511 analog switch ICs, an MC1408 DAC, a CD4053 analog switch, and a couple of opamps.
The sweep board is mostly discrete and makes use of Tek-made timebase capacitors.