I have the service manual (which can be found online), but it's too large to post.
Maybe I'm telling you something you already know, but those have a high failure rate on the U800 IC.
Also, options listed in the manual are:
Option 05 (TV) simplifies triggering and viewing of television
signals. The option adds TV (back-porch) clamp circuitry
to the Channel 2 input and TV trigger coupling
modes, allowing selection of either horizontal or vertical
sync pulses to obtain horizontal-line-sync or field-sync
pulse triggering. This option permits triggering on a
specific line number within a TV field and provides sync
polarity switching for either sync-negative or sync- positive
composite video signals.
Option 10 allows the instrument to be remotely controlled
and queried using a standard interface system. The
interface implemented conforms to the specifications contained
in IEEE Standard Digital Interface for Programmable
Instrumentation (ANSI/IEEE Std 488-1978), commonly
referred to as the General Purpose Interface Bus (GPIB). It
also complies with a Tektronix Standard relating to GPIB
Codes, Formats, Conventions and Features.