HMR is a research project on the recovery of the history and the technology of old computers - with a special focus on Italian ones.
HMR has both historical and technological goals: on the one hand, HMR aims at reconstructing the facts surrounding the development of the early machines; on the other hand, HMR plans to rebuild past computers through simulations and replicas.
HMR is a project of the University of Pisa, started at the Department of Computer Science at the beginning of 2006.
The results of HMR research are part of exhibitions, events and teaching activities of the Museum of Computing Machinery.


In order to rebuild the computers of the past it is mandatory to fully understand their technology. A superficial knowledge does not suffice: all the details need to be explored and understood with curiosity and commitment. Just like it is written in the definitions of hacker given in the Jargon File or in the Internet Glossary RFC 1392.

The Macchina Ridotta

The Macchina Ridotta (MR, meaning Smaller Machine in Italian) was the very first computer designed and built in Italy: it made its dèbut in Pisa in 1957. The MR was the first result of the same project that, in 1961, delivered the more famous CEP (standing for Calcolatrice Elettronica Pisana, that is Electronic Computer of Pisa).
The MR has been the first computer investigated by the HMR project. Today HMR has widened its research goals, but MR remains in the acronym to higlight the origins and the first important success of the project.
The MR almost completely disappeared from the history of Italian computer science. The in-depth investigation of the MR technology made possible to rediscover it and to understand its achievements and its relevance. From an historical point of view, HMR added a whole new chapter to the annals of Italian computer science.
In March 2008, HMR celebrated the 50th anniversary of the MR with a lecture at the course of History of Computer Science. As MR birthday was chosen the date written on the User Manual: March 1, 1958. Actually, the MR was running since July 1957, but early in 1958 it started to deliver computing services to Italian research projects: a meaningful sign of its functionality and reliability.

Experimental Archeology of Computer Science

Information technologies developed quickly. The hardware was (and still is) superseded year by year. Old machines are forgotten, often scrapped. The other half of computer science, the software, was encoded in formats that rapidly became obsolete, the storage media degrade with time and today they are often unreadable. The documentation is lost, often it was incomplete since the start - a bad habit of computer scientists. The protagonists of the events are often still with us, but their memories can not keep track of the many details of extremely complex systems. We need to dig in warehouses and archives, reassemble the pieces and compare them with other contemporary computers and with the technological knowledge of the time. Gaps need to be filled with assumptions and hypothesys which have to be checked and validated experimentally through simulations and replicas.

Further reading

Some details about the story of the MR and the results of the HMR projects are in the following documents:

More info and material (mostly in Italian) are in the inner pages of the website.


Giovanni A. Cignoni, Fabio Gadducci.


Along the years, the HMR project has received contributions from