Mechanical Monsters: Part 1 Flashcards
What was the downside of punch card based machines?
They were hardwired, designed for specific purposes
What was Zuse’s motivation to build his machines?
As a civil engineering student, he became aware of how laborious his calculations were.
What was Zuse known for being the first to do?
First to construct an automatically controlled calculating machine. Not electronic, and didn’t have stored program in memory.
How did Zuse fund his machines, and where did he work after school?
Machines were personally funded; Worked in the aircraft industry
What are the 3 parts of Zuse’s early designs
Control, Memory, Calculator
Why did the Z1 use binary states instead of 10 like other designs?
Zuse was not familiar with other designs of calculators
Z1 Memory
Strips of metal with slots cut into them. A pin would rest on one side of the slot.
What was the problem with Z1 memory
Worked well but complex routing of the ALU made the transport of information between the parts of the machine problematic
Z1 Specifications
Memory: 64 x 22 bit locations
Clock speed: 1 MHz
Z1 Architecture
Keyboard
input (decimal)
arithmetic (binary)
output (decimal)
control (35mm tape)
How did the Z2 improve on the Z1
Designed to overcome the signal routing and reliability problems of mechanical memory by using relays (1939)
Relay memory
More reliable than mechanical sheets, and resources were easier to obtain. However, the cost of the relays was unfeasible for the Z2
What is the major contribution of the Z2
Although it wasn’t practical enough to be put to actual use, it gained funding for the Z3
How did Schreyer want to build the Z2 memory?
With vacuum tubes, although they were scarce during WWII
Z2 specification
Memory: 64 x 16 bit locations
Clock speed: 3 MHz
How did the Z3 improve on previous versions
It overcame reliability problems of the relay technology;
1. Did not use electricity (wear and tear)
2. power only transmitted when contacts are touching (sparking)
Addition and multiplication speed of the Z3
Addition: 0.25 -0.3 seconds
Multiply: Two numbers every 4-5 seconds
Budget of the Z3
25,000 RM (6,500 USD)
Specifications of the Z3
Limited memory: 64 words
Clock: 5 - 10 MHz
Difference between Z3 and Z4
Word size became larger, 22 bits –> 32 bits, 5 - 10 MHz –> 40 MHz
Zuse’s capture by the allies in WWII
They interrogated him to determine whether he was a war criminal or if his research was important to military
Z4 after the war
Had a conditional branch; Only computer in Europe in 1950
Significance of Zuse machines
First automatically controlled calculating machines that were actually functional;
Comparable speeds to later machines;
Remarkable considering limited resources
