My Journey To Find The World’s Oldest Computer

Kevin Murrell, co-founder of the National Museum of Computing, details how he found and helped restore the Harwell Machine

I grew up in Birmingham and, as a geeky teenager, would spend most Saturdays at the Museum of Science and Industry.

Running alongside the canal, the building comprised a vast series of halls on multiple levels with spacious hallways which were rarely subjected to curators or guides.

It was the 1970s and I remember a computer exhibition which is where I first set eyes on the Harwell machine. In fact, I still have a photograph of me hanging around in the computer hall.

From 2009: World’s Oldest Computer To Be Restored At Bletchley Park

Kevin Murell

The World’s oldest computer

Fast forward to 1989 and the museum was subsequently closed, with all its artifacts moved to a rather shabby storage centre before ending up in a purpose-built centre in the heart of Birmingham. In the meantime, I headed off to university and started working but retained my interest in early computing, starting my collection with a classic PDP8 in 1986.

This interest grew and I started to volunteer at a very small computer museum based at Bletchley Park in 1998, looking after their PDP11 kit. When the building we were in came under threat from developers, Tony Sale and myself formed The National Museum of Computing (TNMOC) charity and took over the lease of the building. Tony passed away some years ago, but had a long history in computer restoration.

Harwell Machine

Before long, the museum grew and soon, we had taken over the whole building. At that time, I was also secretary of the Computer Conservation Society (CCS) and it was with this hat on that I visited the Birmingham collection centre in 2007. I had long forgotten the Harwell computer and was on the look-out for something altogether different, but I caught a glimpse of the control panel and remembered it instantly.

I returned several times to identify the rest of the Harwell machine, piecing the various components together. In late 2007, we decided we had found enough and put together a proposal for Birmingham City Council to take the machine to TNMOC and restore it to order.

Throughout this process, we also contacted the original designers, now in their 1990s, who were delighted with the project and by 2012, the machine was fully functioning again.

In its peak in the 50s, the machine was the workhorse of the UK’s atomic energy research programme. Although it was later outpaced by faster, leaner computers, it has always played a pivotal role in education; including its role at the Wolverhampton and Staffordshire Technical College (now Wolverhampton University) where it was used to teach programming, giving its name the WITCH (Wolverhampton Instrument for Teaching Computation from Harwell).

Harwell Machine Makers

Even though it is the oldest working computer in the world, the Harwell is still in daily use as part of the museum’s education programme, and plays a vital role in helping students to understand how computers work. Weighing in at over two tonnes, it is visually impressive and has had everything from oil painting to poems created in its honour. It’s even in the Guinness book of records.

Very little remains from that post-war period of UK computing. So the fact that the Harwell is still around is pretty amazing – let alone that it’s actually functioning. This year, I’ll be joining the line-up at Wuthering Bytes, a ten-day technology festival in the heart of the Pennines, to talk through my journey to find the Harwell, and why it is such an important piece in British computing’s history.

Kevin Murrell,  is co-founder of The National Museum of Computing and speaker at this years’ Wuthering Bytes, a ten-day technology festival taking place in Hebden Bridge from the 1st to the 10th of September. For the full line-up and tickets, visit the official website.