![totem pole output totem pole output](https://d2vlcm61l7u1fs.cloudfront.net/media/a5c/a5c4f013-63f5-4639-8a64-da921ea1a556/phpTFM49B.png)
What is Transistor-Transistor Logic (TTL)? The GUI introduced by Xerox alto in the year 1973 as well as Star workstations in the year 1981 were used TTL circuits which are incorporated at the level of ALUs. In the year 1970, the Datapoint 2200 was used TTL components and it was the base for the 8008 & after that the x86 instruction set. The first PC like Kenbak-1 was used Transistor-Transistor Logic for its CPU as an alternate of a microprocessor. Generally, functions in a single package range from logic gates to a microprocessor. Usually, each TTL chip includes hundreds of transistors.
![totem pole output totem pole output](https://sidoxia.files.wordpress.com/2010/03/totem-pole.jpg)
The Transistor-Transistor Logic was applied to many bipolar logic generations by slowly improving the speed as well as power utilization over about two decades. The one and only one manufacturing company like IBM was launched non-compatible circuits using TTL for their own use. The compatible parts of the 7400 families launched by Texas instruments were designed by several companies like National Semiconductor, AMD, Motorola, Intel, Fairchild, Signetics, Intersil, Mullard, SGS-Thomson, Siemens, Rifa, etc.