Siriluk Kultherawit (B02) www.fourmilab.ch 6 The Evolution Of Computer Interfaces
Siriluk Kultherawit (B02) www.fourmilab.ch 7 Let's look back into the distant past and see how peoples' concepts of how computers would be used have changed. Originally (I'm talking 1950's) it was assumed that a systems analyst would specify how the computer would be applied to a problem. This specification would be given to a programmer, who would lay out the control and data flow to implement the system. A coder would then translate the flowchart into computer code and debug the system, calling on the programmer and analyst as required. The coder's program, written on paper, would be encoded for the machine by a keypunch operator. After the program was placed into operation, it would be run by the computer operator, with data prepared by an operations department.
Siriluk Kultherawit (B02) www.fourmilab.ch 8 Well before 1960, the development of assemblers and compilers (and the realisation that the division was a bad idea in the first place), collapsed the programming and coding jobs into one. The distinction between programmer and systems analyst had become mostly one of job title, pay, and prestige rather than substance in many organisations by 1970. The adoption of timesharing in the 1960's accelerated the combination of many of the remaining jobs. Now, as any computer user could type on his own keyboard, the rationale for data entry departments began to disappear (while concurrently, development of optical character recognition and bar code equipment reduced the need for manual entry of bulk data). In the 1970's, one person frequently designed a program, typed it in, debugged it, ran it, entered data into it, and used the results.
Siriluk Kultherawit (B02) www.fourmilab.ch 9 The concurrent fall in the price of computer hardware contributed to this trend. The division of labour which developed when computers were used in large organisations was impossible and silly when a computer was purchased by a 5 man engineering department. This led to the ``every man a computer user, every man a programmer'' concept that lies at the root of the ``computer literacy'' movement. The skills required to use a computer were still very high, and the areas in which computers were applied were very specialised and generally concentrated in technical areas where users were willing to master new skills to improve their productivity.
Siriluk Kultherawit (B02) www.fourmilab.ch 10 Word processing (and later the spreadsheet) changed all that. With the widespread adoption of the CRT, it was possible to build a user interface that immediately reflected the user's interaction with the computer. With this interface it became possible to build programs that could be mastered in far less time by users with no direct computer-related skills. The personal computer accelerated this process. Now a financial analyst could directly build and operate a spreadsheet model, ask ``what if'' questions, and obtain rapid responses. Now an individual could enter, correct, and format documents which would be printed with quality equal to that of the best office typewriters.