| 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) |
Yes (1998)
|
| Atanasoff–Berry Computer (US) |
1942 |
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) |
No
|
| Colossus Mark 2 (UK) |
June 1944 |
Binary |
Electronic |
Program-controlled by patch cables and switches |
No
|
| 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
|
