History of Computers
History of Computers
Originally (1950s) had to manually load in punch cards
Stuff needed to be automated because computers were extremely expensive and so was idle time.
Batching data is putting a bunch of instructions and data together in order to save time via automation
Tapes can be run in parallel, unlike punchcards
Problem with tapes is that it's sequential access and not random access
Disks are random access, and allow for Simultaneous Peripheral Operation On-Line (SPOOL) which leads to multiprogramming, which leads to less CPU idle time.
Multiprogramming is used for the CPU to swap in and out of programs. It does NOT necessarily mean multicore (multiple CPUs).
Difference between Hardware and Software
Hardware - once fabricated, no change
Software - programs
Moore's law - Number of transistors doubles every 1.5 years per silicon die area
It stopped after 2003 (3 GHz) because the clock speed was getting higher, computers were getting too hot.