Re: Historical Analog Scope Triggering Techniques
There was an FPGA logic analyzer called the "Open Bench Logic Sniffer" that would make a good multi-purpose trigger accessory for a scope by using its trigger out signal. Along with the usual bit matching, it had an advanced mode which had features found in the old HP 16500 series logic analyzer like 10 trigger terms, 2 range terms, 2 timers, and a 16-level state machine. It operated on up to 32 bits of input.
Unfortunately, it's not available anymore, but the schematics, FPGA Verilog code, and host code to control the advanced trigger are all available if someone wanted to use it as a starting point:
The entry under "v3 Demon core in Verilog" has the details on the advanced triggering capabilities.