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'Modern' Computers Turn 60 Years Old
Christian Smith writes "Stored program computers are 60 years old on Saturday. The Small Scale Experimental Machine, or 'Baby,' first ran on the 21st of June, 1948, in Manchester. While not the first computer, nor even programmable computer, it was the first that stored its program in its own memory. Luckily, transistors shrank the one tonne required for this computing power to something more manageable."
US or European? Saftey equipment varies and so do curb weights.
Invenio via vel creo
1.21 Old, 0.74 New.
Zuse's machine didn't have memory, which is part of how they're defining "modern computer."
If you haven't been down-modded lately, you aren't trying.
Sacred cows make the best hamburger.
More specifically, it didn't store software in memory.
They had a programming contest 10 years ago. A pot-noodle timer won and was loaded on the rebuilt machine in a big celebration.
Read more:
Manchester Celebrates the 50th Anniversary of the First Stored-Program Computer
The 1998 Programming Competition
Simulators so you can try your hand at programming a 60-year-old computer.
The Baby is set apart from other early machines by two major features.
Memory was what we would call dynamic RAM. The storage element was special CRT's called Williams tubes which were the first all-electronic memory device (flip-flops we not economically viable for storing data). Williams tubes were randomly accessible and, used charges to store bits, and were therefore volatile. The volatile characteristic means that bits had to be refreshed by reading, or they would evaporate due to charge leakage. This is the same reason modern RAM chips have a periodic refresh cycle. This isn't a functional parallel, just a historically interesting one. FWIW, mercury delay lines are volatile, too, but not because of charge leakage. Programs were read into RAM from which they were executed.
The other feature of the Baby which was adopted into subsequent designs was conditional jumps - sort of like goto's. The relative jump is a jump to a calculated address. Without the ability to hop around the program space based on whether statements are evaluated as true or false precludes easy implementation of things like for loops and arrays. In 1998, the Z3 was mathematically proved to be capable of conditional jumps, but this was not an intent in its design and didn't lead anywhere.
The Baby had only seven instructions (take that, Microchip PIC!):
Jump (indirect), Jump Relative (indirect), Load Negative, Store Accumulator, Subtract, Skip if Accumulator < 0, Halt
A very good and hard to find page with info on the Mark I <URL:www4.wittenberg.edu/academics/mathcomp/bjsdir/madmmk1.shtml/>