My toys over the years

At the Southwest Fox conference, I showed a slide titled “My Toys”

I showed the computer, the processing speed and the amount of memory in a table:



Year     Machine           CPU Speed       Megabytes        Product (Mhz*MB)

1971     PDP-8              .066                  .004                  .000264

1981     IBM PC             4.77                  .25                    1.1925

1991     PC Clone          66                     1                      66

2005     TabletPC           2000                 2000                 4,000,000



Both the processor speed and the RAM increased by several orders of magnitude over the decades. The Speed Memory product of my current tablet is 10 billion times (LOG10(4e6/.000264) => 1e10)greater than my first machine!


At this rate what will a machine look like in 10 years?


In comparison, a 747 Jet has about 40,000 horsepower,  and a human has about 0.17 horsepower, so a jet is only about 2e5 times more powerful than a person.



Related blog posts:

Why was the original IBM PC 4.77 Megahertz?

Thirty years ago, computers were quite different

Relaxen und watchen das blinkenlights. What lights?

Very Old Program



BTW, on another slide I showed a photo of the salmon painted plane I flew to Phoenix: “…among the world’s most intricately painted commercial airplanes”

Comments (8)

  1. Gabe says:

    You have slightly underestimated the PDP-8. The memory on those things came in banks of 4k WORDS, not bytes. Since words were 12 bits, you actually had 6144 bytes of RAM, or .006 MB. Also, the cycle time of an original PDP-8 would be 1.5 microseconds, so it was more like 0.666 MHz.

    This means the MB*MHz is actually .004. So you were off by a factor of 15, but it’s still 9 orders of magnitude difference! Of course a PDP-8 took 2 cycles to add 12-bit numbers, while today’s computers can do simultaneous adds of 32- and 64-bit numbers in a single cycle, so that extra order of magnitude should probably be figured in anyway.

  2. CalvinH says:

    Thanks Gabe: my error. I had the PDP-8 figures correct in the 3rd related blog post (Relaxen und watchen das blinkenlights)

  3. Pooch says:

    Are you a pilot? Did you actually fly the aircraft or were you a passenger?

  4. CalvinH says:

    I should have been clearer. I flew as a passenger in the belly of the salmon plane.

  5. Yes, I saw this plane when arriving for the SW Fox conference last month. Looks pretty cool.


  6. A cartoon can be thought of as a series of drawings. To simulate movement, the drawings can be slightly

Skip to main content