TMMM: Ten Pounds in a Five Pound Sack

The proliferation of cheap computer hardware has made this chapter mostly obsolete but was an interesting read. Aside from running time, the space occupied by the program was its principal cost back in the 1970s.

Consider the IBM APL interactive software system. It rents for $400 per month and, when used, takes at least 160 K bytes of memory. On a Model 165, memory rents for about $12 per kilobyte per month. If the program is available full-time, one pays $400 for software rent and $1920 memory rent for using the program.

– Federick P. Brooks, JR

That’s about USD $13,000 in today’s dollars. In a world where we take space for granted (the front page of a digital newspaper like the New Zealand Herald can exceed 10-20 MB), this was a refreshing read. I really enjoyed that concrete 1970s figures were used, it really emphasises the hardware revolution over the last 50 years or so. This revolution has dramatically lowered cost and greatly improved access to computing hardware.

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