Prior to the introduction of the DDP-series it developed a series of digital logical modules, initially based on vacuum tubes.
[6] In a 1970 essay, Murray Bookchin used the DDP-124 as his example of computer progress: In 1945, J. Presper Eckert, Jr. and John W. Mauchly of the University of Pennsylvania unveiled the ENIAC ... it weighed more than thirty tons, contained 18,800 vacuum tubes with half a million connections (the connections took Eckert and Mauchly two and a half years to solder.
Its architecture was based on a 19-bit word structure consisting of six octal bytes plus a sign bit, which in arithmetic operations could create the unusual value of "negative zero".
One of these machines was donated by the government to the Milwaukee Area Technical College in 1972, which included a drum-based line printer and dual Ampex magnetic tape drives.
It was used for a limited number of students as an "extra credit project device" for the next 2–3 years, after which it was scrapped to make space for newer equipment.