The K-Zone: Sony PRS-500 e-book reader

It's about time somebody produced a gadget which combined the advantages of computer technology (high storage capacity, rapid searching) with the advantages of real paper books (easy on the eyes; straightforward user interface; low power consumption). Many manufacturers have promised us such a gadget, but none has yet really lived up to the promise. Sony claims to have something on offer which is not merely different from what has gone before, but fundamentally different.
      Like many book enthusiasts who have an interest in gadgets, I have from time to time read books on a PDA. In my opinion, the Sharp Zaurus was (and is) a good e-book machine: low (second-hand) cost, two memory slots, and a very clear, sharp screen. However, the screen is hard on the eyes after a relatively short time and, with the backlight on (and it needs to be on most of the time), only allows for a few hours reading to a battery charge. There is a good range of e-book software available, however, and much of it is open-source.
      What makes the Sony PRS-500 fundamentally different from a PDA is its screen. The screen is based on something Sony calls `E-Ink' technology, also known as `electronic paper'. The E-Ink display does not work on a continuous scan principle like most CRT and TFT displays. Instead, the reflectivity of the screen pixels is set on a semi-permanent basis by changing their electrical charge. This has two great advantages over a PDA screen: no flicker, and negligible power consumption. Sony claims a battery life of 7,500 page-turns. If you read, say, one page a minute, that suggests battery life not merely better than you'd get with a PDA, but orders of magnitude better.
      The PRS-500 is not the only E-Ink device on the market -- it's not even the first device from Sony. Sony's first excursion into this field was the Librié -- a miserable failure because of its absurd digital rights management (DRM) system. At the time of writing, the only serious competitor to the PRS-500 is the iRex iLiad which, quite frankly, is presently unaffordable by people of normal means.
      At its launch the PRS-500 received some terrible reviews -- many, it is now obvious, by people who had never actually used the product. Given Sony's history it was generally assumed that the PRS-500 would be burdened by the same execrable DRM limitations as the Librié; in fact, this is not the case. The PRS-500 reads unencrypted, non-DRM files in a number of formats and, what's more, can read them straight off an SD card.

The much-hyped screen

Is the E-Ink screen as good as Sony hypes it up to be? In my view it's not as good as printed paper, but it's far, far better than an LCD display, even of the same size. And you won't get one the same size -- not in a package as small and light as the PRS-500. If you imagine reading a printed book where the pages are grey rather than perfectly white, you'll get the idea.
      The E-Ink display works best in ordinary daylight -- if it's light enough to read an ordinary book without squinting, it's light enough to read the PRS-500. Unlike an ordinary book, you can adjust the font size of the PRS-500 display to make it easier to read in low light. With the largest font setting, I found it perfectly possible to read by candlelight.
      The PRS-500 does least well in conditions where LCD displays do best -- in the dark. The E-Ink display is not backlit (it can't be backlit -- the display material is opaque), and that means you'll need a lamp of some sort to read it in low light, as you would for a real book. Arguably the display could be front-lit; but it's a big screen, and I'm not sure the unit's battery would be up to it. Of course, you can attach a clip-on reading lamp to the PRS-500's case to help in low light.
      The E-Ink screen does suffer from an effect called `ghosting'. When the display changes, an after-image of the previous display lingers for a while. To reduce ghosting, when you turn a virtual page, the whole screen is drawn inverted before being drawn correctly. This process takes about a second. Some users have complained about this, but I don't find it objectionable, given the advantages of the E-Ink screen as a whole. The screen inversion process is not used for menus and navigation, presumably because it would be too slow. So you do see a bit of ghosting there. The impression I get from owner's comments is that either some units suffer more ghosting than others, or some owners are more fussy than others, or both.
      By its very nature the E-Ink display is monochromatic. This is not really a problem for reading novels -- most printed novels are black-on-white anyway. I understand that full-colour E-Ink is technically feasible, but currently too expensive for consumer gadgets.

Formats

The PRS-500 supports Sony's proprietary `BBeB' (`Broad Band Electronic Book') format (a.k.a. LRF format), with and without DRM. As far as I can tell, all the book titles available for download from Sony's `Connect Store' are in DRM-protected BBeB format. These titles can be viewed on up to six devices and, if you pay for a title and then lose it, you can download it again free of charge (provided it is to one of you six registered devices).
Personally I dislike DRM in all its forms -- not because I want to make bootleg copies, but because I can do without the hassle of DRM. The PRS-500 DRM scheme does seem more owner-friendly than the detestable system that killed the Librié, but the pros and cons of Sony's DRM schemes are acamedic outside the USA -- you can only use the Connect Store if you have a US postal address. I had a quick look at what was on offer, and there seemed to be a reasonable range at not-too-painful prices; but it's irrelevant outside the US.

But not to worry -- there is a world of content outside Sony's on-line store. The PRS-500 supports plain text, RTF, and PDF as well as BBeB. In my view, RTF is a pretty good format for e-books: it's simple, and supports most of the formatting and layout found in a printed novel. Most importantly, it's reflowable. That means that the file does not specify the exact positions of the characters on the page, merely the order they are to be presented, with hints about layout. This is of great importance when reading on a display which is smaller than print size: if a document was originally formatted for, say, an A4 page, it will only be readable on the PRS-500 screen (or any smaller-than-A4 screen) if the text can be reflowed to fit the screen.
      For this reason, PDF is a very bad format for e-books. PDF is a page description language, and is not reflowable at all, without losing a lot of formatting. The purpose of PDF is to specify the exact layout of characters on a printed page -- something it does very well. But if you take a PDF formatted for an A4 page, it won't fit onto the PRS screen and still be readable. A number of utilties are available which attempt to reflow PDF, including my own modest ebookconverter program; but the results are rarely very satisfactory. This is not a limitation of the PRS-500 -- it is a consequence of attempting to use PDF for something it was never designed for.
      Of course, if you're producing your own PDF files -- perhaps from other sources (Microsoft Word, LaTeX documents, etc) -- so long as you set the page size to match the PRS-500 screen dimensions, they will normally display reasonably well. Just don't expect any old PDF to be particularly readable, and A4-sized PDFs are a non-starter.
      The PRS-500 does not natively support HTML, but there are a number of utilities circulating that convert HTML to RTF, which is well supported.
      Plain text documents are reflowable to a degree, although not as easily as RTF or HTML. The problem is that reflowing usually loses what little formatting and layout information there is in a plain text document. Again, this is not really a limitation of the PRS-500: there is no standard way in a text document of distinguishing between an end-of-paragraph and an end-of-line (both are usually represented as ASCII carriage return and/or line-feed characters). So it's very easy to get the layout and the formatting mixed up. Reflowing tools are available for text files which make use of heuristics (educated guesses) to work out where the paragraph breaks and headers are, as distinct from line breaks. In principle the PRS-500 could make a better job of displaying plain text than it does. However, my experience is that by adjusting the font size and the screen orientation (landscape/portrait) most plain text files are readable, after a fashion.

Because I mostly use the PRS-500 for reading novels, I'm not particularly interested in its PDF support, to be honest. Most of the stuff I read is in plain text format or HTML, the latter which I convert to RTF using OpenOffice. If you're mostly interested in reading PDFs, particularly formatted for an A4 page or similar, the PRS-500 probably isn't for you.

Storage and document management

The PRS-500 has about 100Mb internal memory for documents (and other supported files), and a memory card slot. The slot takes SD cards up to 2GB, and Sony memory sticks. It's possible that 4GB memory sticks are supported with the latest firmware (reports vary), but 4GB SDs are probably not supported. For most purposes there is no advantage to using a memory card at all, regardless of capacity, for reasons that I'll explain in a moment. But if you don't want to use Microsoft Windows to install documents, you may not have an alternative.

There are essentially two ways to get documents onto the PRS-500: over a USB connection, and on a memory stick. The unit itself has no document management capabilities, which means that USB is the only way to get documents into the internal memory. Or out of the internal memory, for that matter.
Because the PRS-500 will operate directly from a memory stick, you don't necessarily need to store documents in the internal memory. But there are, in fact, good reasons to do so. First, rendering is quicker, so you get faster page turns. Second, the internal memory uses less battery power. Third -- and this may be crucial -- you can't organize memory card content into collections, only internal content.
Collections are simply named groups of books. Because content cannot be organized hierarchically (into directories and subdirectories), collections are the only built-in method of applying an organizational structure to a document collection. Other than this, documents can be listed sorted by author or by title (or filename, for documents which don't have a title). If you have a large number of documents, it can take a long, long time to find the one you want using either of these listing methods. Although collections are rudimentary, they do allow you to group books by genre, or format, or source, or whatever. Of course, if you define more than a few dozen collections, the problem of navigating collections becomes as acute as the problem of navigating titles themselves.

So most users find that although it is possible, in principle, to jam several thousand large books onto an SD card, there's absolutely no point in doing so -- you'll never be able to find what you want to read. This makes the SD card slot effectively useless, except perhaps for storing MP3 audio files (see below). The PRS-500 would be made radically more useable if it supported a hierarchical organization of documents, perhaps using simple directories and subdirectories.
So most users, in practice, find the internal memory more practical than memory cards. The capacity of 100Mb or so is more useful than it sounds, because data is automatically compressed. I currently have about 200 full-sized novels on my PRS-500, in RTF and plain text formats, and the internal memory is nowhere near full. Of course, if you want to read PDFs with embedded images, you may find the 100Mb capacity more limiting.

The internal memory, as I mentioned, is only accessible over USB and, very irritatingly, the PRS-500 uses a proprietary USB protocol. It doesn't appear as a USB hard drive, for example. This means that users of anything other than Microsoft Windows are going to be in for a hard time. The USB protocol has been reverse-engineered, and there are utilities which might allow access for Linux and Mac users. I haven't tried any of these, mostly because they seem to require installing versions of things that would break my Linux system. To be honest, given the speed I read, and given the 200+ novel capacity of the unit, I don't expect that the PRS-500 will compel me to use Windows very often -- probably only a few more times in this life, which I can cope with.
The supplied Windows software worked reasonably well for me, although there have been mixed reactions from other owners. The software allows document files to be copied to the unit, moved around and, if necessary, deleted. It also takes care of installing DRM-protected content, a feature I had no opportunity, or inclination, to test.

User interface and navigation

In my view, this is what lets the PRS-500 down. The unit is excellent for reading a book, one page at a time, from cover to cover. However, it is difficult to find a particular book -- particularly if you have a lot -- and, once you've found it, it's difficult to find a particular page. There are no search or index facilities, nor is there a global history facility. That is, there's no way to get a list of the most recent pages read in all books you're currently reading.
This whole situation is exacerbated by the fact that the PRS-500 displays reading location in terms of pages. Now, that makes sense for a paper book, where the pages are of a fixed size. But the PRS-500 allows you to change the font size, which changes the amount of text on the page, which changes the number of pages in the book. So, as you change the font size, you may find that you skip from page 100, to page 200, to page 400, all while looking at the same sentance. So, although you can bookmark particular pages, you can't tell at a glance whether one bookmark is nearer the end of the book than another, unless you never change the font size.
The rudimentary bookmark system does allow you to maintain a particular reading position in a number of different books (subject to the page numbering complication) but takes some self-discipline to use. Within a book you can skip forward and back one or ten pages at a time, or jump in 10% steps.

The user interface as a whole is, well, quirky and illogical. For example, you can't delete all the bookmarks in a document if you opened the document via a bookmark. You have to find it in the long list of documents to get to the menu that allows bookmarks to be deleted. The page forward/page back buttons are duplicated on the case of the unit, only an inch or so apart. The button that sets a bookmark lights up when you press it, but none of the other buttons do. To some extent, limitations of the hardware itself will impose restrictions on what the user interface can do. The screen is slow to redraw because of the way it works, so you wouldn't want too many pop-up thingies in the user interface. The processor is slow -- presumably to maximise battery life, so you wouldn't be able to do anything too fancy (full-text search might be a bit tricky). But other handheld gadgets manage a better UI with inferior hardware. My overall impression is of a user interface that has not been sufficiently tested by end users before being finalized.
For reading long novels none of this is a serious problem; but if you need to hop from book to book, or even from page to page, you could be out of luck.

The audio player

Yes, the PRS-500 has a built in audio player, which supports MP3 and AAC formats. The unit has the makings of a decent audio player -- it has a memory card slot, a screen, and an audio output -- but it is so poorly executed as almost to be useless. You could, in an emergency, play audio on the PRS-500. But you'd have to be pretty desparate.
The problem is the user interface, again. All the unit can do with audio is play files, starting with a particular item, in alphabetic order of title, until you tell it to stop. Because the PRS-500 has no way to organize content, if you have more than a few dozen audio items you won't be able to find the one you want to play anyway. You can read a book while playing audio but, if you do, it's very easy to forget that music is playing once you take the headphones off, and it won't stop playing until the battery is exhausted. For a few pounds on eBay you can buy an MP3 player the size of a matchbox that offers a better audio-playing experience than the PRS-500.
It's a shame, because the unit could be a good audio player -- all the hardware is there. Some of the problems that need to be solved to make it a good audio player also need to be solved to improve it as an e-book reader, particularly the lack of directory support. It's widely speculated the Sony has deliberately impoverished the audio player in order not to compete with the company's own dedicated audio products. This may be true but, in my view, it's more likely that the developers didn't have time to do a more extensive job.

Image viewer

The PRS-500 will display images in JPEG and other formats. I can't really think of any use for this feature, given that the screen is not merely monochromatic, but only has two shades of grey. Streetmaps, maybe? Anyhow, I don't use it, and can't comment on how well it works.

Battery

The battery life of the PRS-500 really does seem to be ask good as claimed, at least if the battery meter is reliable. I've only charged mine once since it arrived, and that was only because I left the audio player running. The battery meter is still showing full charge, after several weeks of intensive use.
I should point out that, although the unit will charge over the USB connection, it needs to be told to charge, and that can only be done by the supplied Windows software, or something reverse-engineered from it. Merely plugging the unit in to a USB socket won't charge it. However, the unit has a mains charger, so that isn't an insurmountable problem.

Conclusion

For reading novels, the PRS-500 offers an experience much nearer to reading a proper, printed book than anything else I've come across. But it has the advantage of a capacity of hundreds of books (maybe thousands, if Sony fix the user interface problems). There are plenty of free and out-of-copyright books that can be read on it, without resorting to paid-for DRM content. Battery life is very impressive (weeks or months), and the unit is tolerably portable.
On the negative side, the user interface is irritating and illogical when it comes to doing anything other than reading a particuar book. Developer effort that has been put into the pointless `bonus features' -- such as the MP3 player -- would have been better employed improving the operation of the major functions of the unit. The lack of support for environments other than Microsoft Windows is irksome, but not entirely unexpected. The unit is completely dependent on Windows, but Windows users certainly have a much easier time of things.