The computer systems that you use today are a result of 50 years of evolutionary success. Computers started from as simple machine as abacus and have evolved through as complex as IBM and apple server machines. However, the foundation of the current computer systems was laid during the 80s and 90s. This was the era in which Apple and IBM produced desktop systems and Microsoft started releasing windows based GUI operating systems.
In the 80s, computers were pretty simple with 4.7 MHz processor and 2kb of RAM. Programmers had to write to computer programs line by line and there was no way of saving the program. Also, debugging was one heck of tasks. In the 80s IBM was the prime computer manufacturer with systems prices dangling around $1000. Commodore 64 was the first real powerful machine introduced by IBM in those days. It would be unfair without mentioning Apple manufacturers. Apple systems were used mostly in school back in those days. However, apple and windows DOS OS wasn’t that successful in those days. Apple OS could only run on Apple hardware, while IBMs hardware could run BASIC language programs.
Come, the 90s when computer software and hardware industry really started to take off. In early 90s, 286 and 386 were ruling the hardware industry. During the early 90s, Microsoft’s Windows 3.1 coupled with DOS had taken over as the most successful and widely used OS. With good hardware memory and sound knowledge of DOS, user could perform most of the basic to advance level tasks. In DOS, only one program could be run while Windows provided multi-tasking (Actually pausing the one task and starting the other). 14.4K modem was used to connect to internet with landline phone.

In the later 90’s Pentium processors were introduced and with the advent of Windows 95 and then later Windows 98, things started to take a sharp turn. Multitasking was implemented in its essence and the OS’s were much robust. It is safe to say that the astonishing progress that we are seeing today in the field of computer software and hardware is a result of the seeds sown in the 80s and the 90s.

photo credit: Computers in Haning Hall at Ohio University, 1984 via photopin (license)