The pic tvosd consists of two sections.

1: The video sections which uses the STV5730A (surface mount) mounted on a simmstick pcb which has been designed for a Atmel micro.Below is a link to the Dontronics site were a basic kit can be purchased and the schematic for the video section can be obtained. Only the video section is built and used .
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http://www.dontronics.com/dt108.html

2: The pic controller section which can either be done on another simmstick (this is what I use for development or veroboard. The max232 serial chip can be located on either and some wire links inserted to connect the pic to the max232.
Here is a link to the simmstick pcb

http://www.dontronics.com/dt106.html

The pic schematic can be obtained from the link below also the hex files are available. At the moment two files are available 1.0e is a solid text version and 1.0f is a text overlaid onto a video signal.
There will be at least one more version which will incorporate a toggle switch to select which video version to display . Maybe more enhancements such as flashing leds / beeper to indicate an “Alert Message”has been received.

Pic schematic

Version 1.0e

Version 1.0f