Technology from the pre-iPhone days

▼ Yesterday I posted this to Twitter:

Kicking it old school while my iPhone 5 is undergoing battery surgery.

And then this morning I saw Andy Ihnatko had a video based on a similar photo, where he extolled the virtues of the 20-year-old versions of the technologies now bundled inside an iPhone: Why 2013 Won't Be Like 1993. (Part of his effort to decide once and for all whether doing video is for him by doing three a week for a month—recommended.)

And yes, the old stuff does have some advantages. As someone on Twitter mentioned: "i wish you a happy week with no need for recharging :-)" It's true, the Nokia 6310i from 2002 easily lasts a week on a charge. However, I think if you only use your iPhone for making a short phonecall a few times a week, it also lasts for many days... And the dead tree book doesn't need any power at all!

When I brought in my iPhone 5 at the Apple Store yesterday, they first tried to repair it in the store, but when I came back later they told me the repair was unsuccessful so they had to send the phone away, and it may be as much as two weeks before I get it back. They did give me a loaner 16 GB iPhone 5, though. Not easy to get everything into 16 GB (well, just over 12, really) when 32 GB (= just under 28) was already cramped before.

Permalink - posted 2014-09-02

iPhone lock screen tip: audio controls vs large clock, timer

▼ After six years of using one, it's not often that I stumble upon an iPhone trick I didn't know before. But here's one. When looking at the lock screen when audio is playing, press the home button and the audio controls are replaced with the large clock that the lock screen normally shows when no audio is playing.

This is the lock screen when playing music:

The time can be hard to make out on this screen when on the move. So press the home button and voilà:

But it gets better. A while ago I noticed that if you have a timer running, the lock screen will show you the timer. Unfortunately, not when playing back audio. Again, pressing the home button fixes this:

Not a big thing, but very useful!

Permalink - posted 2014-08-27

Existing and upcoming iOS device screens and the metric system

▼ Have you ever noticed how the iPad has strange screen sizes? 9.7 and 7.9 inches. The same for the rumored new iPhone sizes: 4.7 and 5.5 inches. Turns out some of these screen sizes are nice, round numbers... in the metric system.

First a short metric system refresher for my American readers. It all begins with the meter (m). Long distances are measured in kilometers (1 km = 1000 m). Short distances are measured in centimeters (100 cm = 1 m) or millimeters (1000 mm = 1 m, 10 mm = 1 cm). A liter (l) is a volume the size of 10 by 10 by 10 cm, and a liter worth of water weighs 1000 grams, or a kilogram (kg, also just "kilo" in common parlance). The main thing you have to remember is that an inch is 2.54 cm or 25.4 mm.

Interestingly, on its English language web pages, Apple dutifully lists all the outward dimensions of the iPad Air both in inches/pounds and (tens of!) millimeters and grams. In other languages, only millimeters/grams are mentioned. Except for the screen. That's 9.7 inches, period. Even in French. The same thing for the iPad mini with its 7.9" screen.

Let's do some calculations:

	Screen diagonal
iPhone 4	3.5" x 2.54 =	8.89 cm
iPhone 5	4" x 2.54 =	10.16 cm
iPad Air	9.7" x 2.54 =	24.64 cm
iPad mini	7.9" x 2.54 =	20.07 cm
iPhone 6 small	4.7" x 2.54 =	11.94 cm
iPhone 6 big	5.5" x 2.54 =	13.97 cm

Not so round. However, if we also take into consideration the pixel resolution and pixels per inch numbers that Apple publishes, things look slightly different:

	Resolution	PPI	Screen in	D in	px/cm	Screen cm	D cm
iPhone 4	960x640	326	2.95x1.96	3.54	128	7.5x5	9
iPhone 5	1136x640	326	3.48x1.96	4	128	8.88x5	10.19
iPad Air	2048x1536	264	7.76x5.82	9.69	104	19.69x14.77	24.62
iPad mini	2048x1536	326	6.28x4.71	7.85	128	16 x 12	20

(Screen in / Screen cm: screen height x width in inches / cm. D = screen diagonal.)

Conclusion: the iPhone and iPad mini use a pixel density that makes for nice round numbers for the display size in the metric system, with the original iPad being the odd man out. So what about the rumored 4.7" and 5.5" sizes for the iPhone 6? That would be 11.938 and 13.97 cm, respectively. Which probably means it's going to be 12 and 14 cm, or 4.72" and 5.51".

John Gruber's conjecture lands at 750 x 1334 for the small one. If that one has a 12 cm screen at 326 PPI = 128 pixels/cm, that comes out to:

	Resolution	PPI	Screen in	D in	px/cm	Screen cm	D cm
iPhone 6 small	1336 x 752 *	326	4.11x2.31	4.72	128	10.46x5.88	12

Note that this is different from the 1366 x 768 result I got last week. I then used 10 cm for the iPhone 5 screen size, and assumed 4" → 4.7" actually meant 10 → 12 cm, a 20% increase. But the iPhone 5 screen is actually 10.2 cm, so a 20% increase in size would be 10.2 → 12.24 cm, which is 4.82" and not in the 4.65" - 4.74" range that would be rounded to 4.7". I think if Apple had wanted to stick with 326 PPI / 128 pixels/cm, they'd have gone for the extra 2.4 mm diagonal screen size, which only adds only 1.2 mm to the width of the screen but makes the pixel numbers work out much better.

I still think 1280 x 720 is the most likely resolution for a 12 cm iPhone 6, because it's a nice round number and allows for slightly bigger text for unupdated applications while still providing a reasonable number of extra pixels. Assuming the 14 cm version would use the same pixel density, that comes out to:

	Resolution	PPI	Screen in	D in	px/cm	Screen cm	D cm
iPhone 6 small	1280x720	311	4.11x2.31	4.72	122	10.46x5.88	12
iPhone 6 big	1488x840 *	311	4.8x2.7	5.51	122	12.2x6.86	14

But we'll know soon enough.

* Rounded a bit to a number divisible by a power of two.

Permalink - posted 2014-08-26