Ttl
In electronics, TTL refers to a way of doing logic in circuits
- historically, Transistor-Transistor Logic (transistors perform both the logic as well as any amplfication) replaced earlier styles, mostly resistor–transistor logic and diode–transistor logic
- practically often just means "logic at 5V"
- which now is often in contrast with newer, lower-voltage (often 3.3V) logic levels
As a file extension, .ttl may point to turtle format of storing triplets