Weekly Classic Computer Trivia Question (20141205)

On Sat, 6 Dec 2014, Johnny Billquist wrote: 1,474,560 IS, indeed 1440 * 1024 If you use powers of 10, it would be 1.47 M. If you use powers of 2, it would be 1.40624 M. SO, how did they get "1.44 M"? (rhetorical question; don't you hate rhetorical questions?) In order to get "1.44", they stated that it was 1440 Kilobytes, (where "kilobyte" was the traditional COMPUTER meaning of 1024. Then they divided 1440 by 1000, to get 1.44. They defined "Megabyte" to be 1000 kilobytes (1024)! Therefore, they divided by 1024 AND divided by 1000. You can make a case for powers of 10; you can make a case for powers of 2; it takes marketing assholes to mix them. If you round to "1.4 M", then at least it doesn't pin the needle on the bogusimeter. The ST506, when formatted with 512 byte sectors, was 306 * 2 * 17 * 512 for 5326848 5326Ksi 5202Kibi 5.33Msi 5.08007815Mebi The ST412, when formatted with 512 byte sectors, was 306 * 4 * 17 * 512 for 10653696 10653Ksi 10404Kibi 10.4 Msi 10.16015625 Mebi In those days, the rounding wasn't a big problem, and either set of units would do. NOTE: In contrast with modern marketing, Seagate did NOT try to "maximize" the numbers by changing units nor using extraneous "significant" digits. They called the 506 a "5 Megabyte drive", NOT "5.33" nor "5.08". They called the 412 a "10 Megabyte drive", NOT "10.4" nor "10.16". 'course part of that was the higher prevalence of bad sectors. If'n you buy a "10.4 Megabyte" drive and it ends up formatting to 10.2 (due to some bad sectors), you gripe about the quality. OTOH, if you buy a "10 Megabyte drive", and it formats to 10.2, then you brag to all of your friends about what a great drive you got. (and Seagate gets a better reputation) [for some value of indeterminate "you", not speaking to Eric or Tony] -- Grumpy Ol' Fred cisin at xenosoft.com