A study is conducted with 368 teachers teaching various undergraduate Computer Science and Computer Engineering courses in an under-developed country - Pakistan, during the COVID-19 pandemic. A teaching model is presented in this research, suggesting that the grit had played an important role in technology adoption for online teaching during the COVID-19. It is found that although the absence of technological support such as high speed Internet and consistent, robust and useful LMS, teachers were still adopting and using technologies such as Google Classroom, Zoom and WhatsApp groups for teaching the students in real-time or through recorded videos. This behavior is explained by the teacher's grit that has also motivated the adoption of online teaching related technologies. The lack of technology such as LMS does affect the user satisfaction, however, it didn't affect the usage behavior of the adoption and use of technology. The initial research model had components from non-cognitive learner characteristics, and from various popular technology usage and acceptance models such as an Information System success model, and Unified Theory of Acceptance and Use of Technology. A quantitative questionnaire survey is conducted to assess the proposed research model. The resultant research model had components only from non-cognitive learner characteristics and Unified Theory of Acceptance and Use of Technology model. The data is analyzed using SEM PLS, K-means clustering and Decision Tree classification method.