History of Computers

BTL-1
Inventor : George Stibitz
Builder: Bell Labs
Operational: 1939
Retired: 1949
Cost :20,000$

Size : 8' x 5' x1'
Technology: Relays, Teletype
Memory: 2 Complex Numbers
Program: Fixed, complex arithmetic calculator
Speed: 02 operations per second

Z3
Inventor: Konrad Zuse
Builder : Konrad Zuse
Operational : 1941
Retired: 1944(Destroyed)
Cost: $6500
Size: Two 6' x 3' x1' Memory racks
Technology: Relays
Memory : 64 22-bit floating point words
Program: 35mm punched film
Speed : 0.5 Operations per second
Application: Circuit Analysis, defense, prototype

Atanasoff-Berry Computer(ABC)
Inventor : John V. Atanasoff
Builder : Atanasoff and Berry
Operational : 1942
Cost : $ 7000
Size : 6' x 3' x 3'
Technology : Tubes, capacitors, cards
Memory : 64 50-bit words
Program : Fixed, Matrix arithmetic calculator
Speed : 32 operations per second
Application : Linear Algebra

ASCC(Automatic Sequence Control Calculator) or Harvard Mark 1
Inventor : Howard Aiken
Builder : IBM
Operational : 1943
Retired : 1959
Cost : $500,000
Size : 51' x 8' x8'
Technology : Relays, Punched card, plugboards
Memory : 132 23-digit words
Program : Punched Card Type
Speed : 3.3 operations per second
Application : Defense

SSEC
Inventor : Wallace Eckert
Builder : IBM
Operational : 1948
Size : 25' X50' floor plan
Technology : Tubes, Cards, Relays
Memory : 160 digits in vacuum tubes , 300 in relays, 400,000 on punched tape
Program : IBM punched card stock
Speed : 50 multiplications per second
Application : Astronomy, Defense

ENIAC(Electronic Numerical Integrator and Computer)
Inventors : J. Presper Eckert and John Mauchly
Builder : Moore School, University of Pennsylvania
Operational : February 14,1946
Cost : $500,000
Size : 40 panels arrnage in a U-Shape
Technology : 18,000 Vacuum Tubes
Memory : Flip-flops, function table, Plugboards, cards
Program : Wires, plugboard, function table
Speed : 5000 operations per second