Defining characteristics of some early digital computers of the 1940s
(In the history of computing hardware)
|
Name
| First operational
| Numeral system
| Computing mechanism
| Programming
| Turing complete
|
Zuse Z3 (Germany)
| May 1941
| Binary floating point
| Electro-mechanical
| Program-controlled by punched 35 mm film stock (but no conditional branch)
| In theory (1998)
|
Atanasoff–Berry Computer (US)
|
| Binary
| Electronic
| Not programmable—single purpose
| No
|
Colossus Mark 1 (UK)
| February 1944
| Binary
| Electronic
| Program-controlled by patch cables and switches
| No
|
Harvard Mark I – IBM ASCC (US)
| May 1944
| Decimal
| Electro-mechanical
| Program-controlled by 24-channel punched paper tape (but no conditional branch)
| Debatable
|
Colossus Mark 2 (UK)
| June 1944
| Binary
| Electronic
| Program-controlled by patch cables and switches
| In theory (2011)
|
Zuse Z4 (Germany)
| March 1945
| Binary floating point
| Electro-mechanical
| Program-controlled by punched 35 mm film stock
| Yes
|
ENIAC (US)
| July 1946
| Decimal
| Electronic
| Program-controlled by patch cables and switches
| Yes
|
Manchester Small-Scale Experimental Machine (Baby) (UK)
| June 1948
| Binary
| Electronic
| Stored-program in Williams cathode ray tube memory
| Yes
|
Modified ENIAC (US)
| September 1948
| Decimal
| Electronic
| Read-only stored programming mechanism using the Function Tables as program ROM
| Yes
|
EDSAC (UK)
| May 1949
| Binary
| Electronic
| Stored-program in mercury delay line memory
| Yes
|
Manchester Mark 1 (UK)
| October 1949
| Binary
| Electronic
| Stored-program in Williams cathode ray tube memory and magnetic drum memory
| Yes
|
CSIRAC (Australia)
| November 1949
| Binary
| Electronic
| Stored-program in mercury delay line memory
| Yes
|