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0 pointsvarjag5y ago0 comments

I am very aware HD manufacturers pushed through the megabyte rebranding via SI back in late 1990s. There is no good technical reason to have inherently power of two quantities in power of ten measures.

The reason for re-standardization effort was deflection of legal responsibility for misleading marketing:

https://en.wikipedia.org/wiki/Byte#Lawsuits_over_definition

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4 comments · 1 top-level

soneil5y ago· 3 in thread

Whats inherently power of two about them?

I have two PS/2 era drives that predate your "rebranding". One, 20MB (actual 21.3MB or 20.3MiB) has a CHS geometry 612x4x17. The other, 40MB (41.5MB or 39.5MiB) has a CHS geometry of 1038x2x39.

None of these values are powers of two (other than heads, because platters happen to have two sides)

I'd argue that all we're seeing here is the long, long tail of lazy shortcuts taken in the early-home-computer era. Not a truth, a lazy shortcut - that software took as convention and hardware didn't.

varjagOP5y ago

Addressing and alignment of computer memory on binary architectures is happening on binary boundaries due to arithmetic properties. You can not buy a 1,000,000,000 bytes RAM chip for that reason.

Magnetic and paper tape, drums, delay lines and hard disks are (imperfect) hacks to have more memory due to cost of RAM.

grishka5y ago

> due to cost of RAM.

And its volatility.

Volundr5y ago

TIL that hard drive platters are two sided. It makes perfect sense you can store data on both sides, yet never occurred to me before.

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