Examples of series machines
For example, IBM370 series machines have 370, 115, 125, 135, 145, 158, 168 and a series of various models from low speed to high speed. They have the same system structure, but adopt different composition and implementation technologies, and have different performance and prices. They have the same instruction system, but the analysis of instructions and the execution order of instructions are carried out on the low-end machine, while the high-end machine adopts overlapping, pipeline and other parallel processing methods. From the programmer's point of view, each machine has the same 32-bit word length, but from low-end to high-end machines, the width of the data channel is 8 bits, 16 bits, 32 bits, or even 64 bits.
Compatibility issues of series machines
A system structure can have multiple components. Similarly, a composition can have multiple physical realizations. The series of machines have the same machine attributes from the programmer’s point of view, so the machine language programs and compilers compiled according to this attribute can be universally used for all grades of machines, so all grades of machines are software compatible, that is, the same software can be modified without modification. When running on machines with the same system structure in different gears, the same results can be obtained. The only difference lies in the different running times. The series of computers have better resolved the contradiction between the software requirements for a stable environment and the rapid development of hardware and device technology, and achieved the purpose of software compatibility. However, in order to ensure the compatibility of the software, the serial computer requires the system structure not to be changed, which undoubtedly becomes an important factor hindering the development of the computer system structure.
