The Software Tools

From the start of the MU5 project it was clear that the productivity of the software group would be a critical factor, and a lot of emphasis was placed on the provision of software tools. The project aim of designing the hardware to fit the software requirements meant that the software design had to run ahead of the hardware design. Also, since the evaluation of the completed system was to be based on its high-level language job processing ability, ‘good’ software would be required soon after the hardware commissioning was complete. It was felt very strongly that the only way to achieve good software was by expending effort in producing prototypes of each component, and that only by running them on other machines, or possibly on partially commissioned hardware, would the timescale be met. In fact during the 10 years from 1968 to 1977 the MU5 software group (of about 20 people) produced 10 operating systems and 15 compilers in addition to the software tools programs. Furthermore, it was recognised that to be useful as a basis for the design of their successors, these prototypes had to have a readily understandable external representation.