Final answer:
The IAS model's key concepts include memory content being addressable by location irrespective of data type, storing data and instructions in a single memory, and executing instructions sequentially.
Step-by-step explanation:
The question relates to the key concepts of the IAS computer model, which stands as an early architecture for the design of digital computers. The options provided a), b), c), and d) attempt to outline the fundamental principles of this architecture. To answer which of these are the key concepts:
- a) The contents of memory are addressable by location regardless of the type of data. This refers to the concept that in the IAS machine, each location in memory can be accessed directly, and the nature of the content (whether data or instruction) does not affect the method of access.
- c) Data and instructions are stored in a single read-write memory. This is one of the IAS model's distinguishing features, which broke away from the practice of separate storage, leading to the idea of the 'stored program concept' where instructions for the machine are stored in the same memory as the data.
- d) Execution occurs in a sequential fashion. This reflects the early design of computer processors where instructions are executed one after another in a sequence, a direct contrast to modern parallel processing concepts.
Option b) 'Data transfer occurs between CPU and memory only' does not distinctly represent a key concept of the IAS model, as the architecture does not specifically limit data transfer between only CPU and memory. Other components such as input/output devices also play a role in data transfer. Therefore, the correct key concepts of the IAS model included in the options given are a), c), and d).