Is memory size written in KB?

Answer 1

It could be, but many modern computers have 8GB or more, that is 8 million KB!

The amount of memory a given computer may have could be written in B, KB, MB, GB, etc. by using the appropriate binary-metric prefix.

Examples:

• 128B the internal RAM of a simple microcrontoller
• 64KB the typical memory of an early 1980s microcomputer
• 2.7MB the amount of memory required to save a photo
• 12GB memory of a modern laptop computer
• 256GB memory of a modern supercomputer
• etc.

However prior to 1964 when IBM released their line of System 360 computers and defined the byte as being 8 bits, memory size was measured in many different units:

• words, used on "scientific" computers (most were binary, but a few were decimal). Typical word sizes varied from about 36 bits to 60 bits (on decimal computer words varied from about 10 digits to 18 digits) with memory sizes typically ranging from 1K words to 32K words.
• characters or digits, used on "business" computers. These systems were all decimal, characters were usually 6 bits + 1 parity bit (7 bits), digits were usually 4 bits + 1 parity bit (5 bits) with memory sizes typically ranging from 20K characters/digits to 100K characters/digits. Many business computers had variable "word" size.