Jun 05 2007

Magnetic “Beads”

Published by at 8:46 am under retro

This blog page has a beautiful close up shot of early magnetic core memory in an IBM 704 built in 1954. The text which is presumably from the accompanying 1954 text refers to the cores as “beads”. In the photo you can make out the two perpendicular wires going through each of the cores on what is a hand made board which contains an array of 6 by 12 cores or 72 bits.

Silly calculations:

  • Were one to build a one gigabit memory board with the same density, it would need to be about 24,000 sq. ft. or approximately half a football field. Can’t imagine the power consumption.
  • Computational capability from the 10 Million ops/hour to today’s CPU chips has grown at an average of about 30%; a doubling in a little less than three years. Slower than Moore’s law predicts. Reflecting the inclusion of a period of this older technology that preceded integrated circuits.

Thanks to a correspondent further west for the link.

No responses yet

Trackback URI | Comments RSS

Leave a Reply

You must be logged in to post a comment.