Why were early computers difficult and expensive to use?

Early computers were difficult and expensive to use primarily due to their specialized design, the high cost of machine time, and the lack of accessible interfaces.

Reasons for Difficulty

• Expert-Only Operation: Computers were operated by a "priesthood" of specialized technicians. Users often had no direct contact with the machines; instead, they relied on a multi-step process involving coders, keypunch operators, and computer operators to process data via punch cards.1
• Complex Programming: Early machines required programming in machine language, which was highly detailed and far removed from natural or mathematical language. The lack of high-level languages and automatic translators meant that users had to be experts to prepare problems for computation.2
• Limited Functionality: These machines were largely restricted to tough mathematical problems and lacked text-handling capabilities, such as the ability to represent lowercase letters.3

Reasons for High Cost

• Resource Scarcity: Computers were massive, room-sized "Big Iron" machines built one at a time. Because they could only process one problem at a time, machine time was extremely expensive—often more costly than the time of the scientists using them.31
• Inefficiency: Due to the high cost of machine time, it was not considered cost-effective to use computers for tasks that humans could perform, such as program translation.2