Planning and organizing a voluntary project

Enthusiasm for the project’s challenge was so high that at the start the question of funding was subsumed as a problem to be solved later a working plan was seen as the first priority. We had just three and a half years before the deadline, a date that could not be changed. To keep the various interested parties on track, a small steering group was formed in March 1995, chaired by Cliff Jones. The group included Peter Hall, a former director of ICL and chairman of the local group of the CCS; Jenny Wetton, curator of science at the Museum of Science and Industry in Manchester (MSIM); Frank Sumner, former director of the Manchester Computing Centre, which provided the university’s computing service; and me. The group’s composition changed slightly during the project. Two notable changes were Steve Furber, who took over as chair when Jones moved to the University of Newcastle-on-Tyne, and later the addition of Tom Hinchliffe, managing director of ICL High Performance Systems at nearby West Gorton. I was confirmed as project manager. The steering group’s quarterly meetings enabled me to report on progress and highlight problems, and let the other members feed back a coherent picture into their own organizations so that the replica project could be coordinated with the increasingly ambitious celebratory plans for June 1998.

The overall plan as outlined in my proposal featured a demonstration apparatus, later called the feasibility rig, which would be built as soon as possible to show that a CRT memory could be made with period components and original circuit designs. It was assumed that the rig would contain about 40 valves (vacuum tubes) in one 19-inch-wide rack, about 6 feet high. This was a single-handed task for me as the project manager, and was to be ready by the end of 1995. During the same year, investigations into any available documentation of the original SSEM, and into the availability of obsolete electronic components, would be carried out. Thereafter a team of volunteers would be recruited to carry on detailed investigations into all parts of the SSEM and to physically assemble the machine to be ready by the end of 1996. The team would then devote 1997 to making the machine work (that is, solving the problems not revealed by examination of documents), and leaving the first half of 1998 as contingency time before the goal date of 21 June 1998. So the very simple plan evolved:

This plan worked quite smoothly. Establishing a volunteer team turned out to be pleasantly easy. A group of CCS members including Adrian Cornforth, George Roylance, Ken Turner, and Keith Wood, and led by Charlie Portman—had spent almost a year carrying out the physical conservation of an incomplete Ferranti Pegasus computer (1957 vintage) on display at the MSIM. Adrian is a busy software engineer with an interest in the history of early computers. Charlie was an ICL Fellow doing advanced systems research in ICL,in the few years before his scheduled retirement. The others were all retired engineers from ICL and had known each other, as well as Charlie and myself, reaching back to the days of vacuum tube computers in the Ferranti Computer Department in the 1950s and 1960s. George had worked on the Manchester University Atlas computer development and had been a voluntary worker at the museum for some years. Ken had worked on magnetic drum development in those far-off days, and now taught computer studies part-time, while Keith had been a development engineer on projects ranging from vacuum tube computers to artificial intelligence.

The Pegasus conservation work was carried out on Tuesday evenings at the museum, which has a well-organized structure for volunteers to look after museum artifacts such as railway locomotives, aircraft, and textile machinery, among others. After conserving the Pegasus, it was agreed that restoring it to full operation would be inappropriate because there was already a working Pegasus in London. So, by early 1995, this group was a ready-made team looking for more work.

My friendship with Charlie and the others meant that it was natural that he and his group should be invited to form the nucleus of the SSEM replica team. I also asked Bill Purvis—who we vaguely knew through his attending CCS evening lectures, and who I found had a mutual interest in cave radio and electronics (speleonics) if he would be interested. Bill was also a software engineer, who at the time worked at the Daresbury High-Energy Physics Research facility and who was an enthusiastic and versatile engineer. All these people met for a Sunday session at my house in late 1995 to get introduced to the project and accept their different tasks and commitment to the overall goal and objectives. Adrian had less experience of hardware construction but produced at least one chassis for our project. In particular, he took on the parallel crucial task of creating, developing, and maintaining the original version of the CC