Oh, The Places We Have Been

Background: As you know, I am fascinated with the pace of technological growth since I was your age. The Pocketronic, the first "pocket" calculator, came out when I was in junior high school. The first personal computer was not introduced until I was in college. Only several years thereafter did personal computers become commonplace.

This advance in technology was vividly illustrated to me this weekend when I purchased a portable hard drive (a Western Digital (WD) Passport). As I was trying it out I looked at an Apple Disk II floppy drive in my den and was amazed how much larger it was compared to a modern portable hard drive. I then looked at the Apple Mac Mini which sets atop my PC. The entire Mac Mini computer was considerably smaller than the Apple Disk II drive. To help you share in my fascination, you will compare the volume, mass, price and secondary storage capacity of these three devices.

Before you begin, here are the answers! Compared to the WD Passport, the Disk II costs about ten times more in constant dollars and has a mass and volume about twelve times more. The WD Passport stores over one million times the data as the Disk II, however! Compared to the Mac Mini, the Disk II costs about three times more in constant dollars, takes up over twice the space and has a mass about 50% greater. The small hard drive in the Mac Mini, however, holds over 350,000 times the data of a Disk II.


Apple Disk II
Apple Mac Mini
WD Passport Hard Drive
Secondary Storage (GB)
Length (cm)
Width (cm)
Height (cm)
Mass (kg)
Price ($)

(Qualifications: For secondary storage, treat 1GB as equal to 1 billion bytes instead of ten to the 30th power. The length, width, height and mass are informal measurements that I made and are not from the manufacturers. In particular the mass should be viewed as a rough figure done with the bathroom scale and a small kitchen scale. The price of the Apple Disk II is from Wikipedia referring to the 1978 price with controller card and cable. The capacity for the Apple Disk II was 112 kilobytes or 140 kilobytes according the Wikipedia article depending on when the controller card was produced.)


You are going to prove the answers I gave you. You must use Excel for all calculations. Use the following format on Excel. Use narrow columns as I have done so you can print it out in landscape mode with one sheet of paper. You can have two lines in a heading by going to Format, Cell, Alignment, Wrap Text. Basically, your job will be to fill in the question marks.

Here are the specific steps you must do.

1. Calculate the volume of each device. Treat each as a rectangular prism. Remember that the volume of a rectangular prism is equal to the length x height x width.

2. Calculate the ratio of the volume of the Apple Disk II drive with the volume of Mac Mini and the portable hard drive. The ratio for the Disk II compared to Mac Mini goes in cell J3. The ratio of the Disk II compared to the portable hard drive goes in cell J4.

3. Calculate the ratio of the mass of the Apple Disk II drive with the mass of Mac Mini and the portable hard drive. Answers go in cells K3 and K4.

4. Calculate the ratio of the price of the Apple Disk II drive to the price of the Mac Mini and the portable hard drive. Answers go in cells L3 and L4.

5. In general, you could buy a lot more with a dollar in 1978, the year the Disk II came out, than you can today. For example, a loaf of bread in 1978 might have be $.50 and today it might be $1.50. The Consumer Price Index put out by the U.S. Department of Labor, Bureau of Labor Statistics ("BLS"), measures this effect of inflation. They have a handy inflation calculator at the BLS home page. Use this to find how much the $595 Disk II drive in 1978 would cost in 2006 dollars. Then calculate the ratio of the price of the Apple Disk II drive to the price of the Mac Mini and the portable hard drive. Answers go in cells M3 and M4.

6. Calculate the ratio of the secondary storage capacity of the portable hard drive with the Disk II and Mac Mini. Your answers go in cells N2 and N3.

7. Put your name in a cell. On the spreadsheet, highlight what you have done. Print it out being sure to print in landscape mode. Put your finished page on the middle student desk in the front of the class.