RISC World

Explan/VideoSeven 17 inch LCD Monitor

Andrew Rawnsley throws his old CRT monitor in a skip.....

Flat panel LCD monitors have been around for a while now, but due to the high costs involved (just one particle of dust during manufacturing can render a whole panel unsaleable) it has been hard for many of us to justify purchasing one, when comparing with traditional CRT (cathode ray tube) monitors. In order to bring prices to the sub-£500 mark, manufacturers have concentrated on panels with 15" diagonal size, which are a little smaller than most 17" CRT monitors.

If you wanted a larger screen, most companies jumped to 18" panels usually costing £2000 or more, which is clearly beyond the depths of most people‘s pockets! The L17A, however, solves this problem rather elegantly by offering a high resolution, half-way-house with 17" diagonal (equivalent to a 19" CRT) and a price tag just creeping under the £1000 price point. It‘s still not cheap, but when you consider that an extra inch will cost you nearly twice as much, it puts things into perspective. Oh, and thanks to Explan, it just happens to be fully RISC OS compatible.

CRT monitors vs LCD panels

Since this is likely to be many people‘s first proper experience of LCD flat panel monitors (on desktop computers, anyway!), it is, I feel, worth digressing into a little background. LCD panels are quite unlike their CRT brethren - we have already seen that the diagonal sizes quoted are pretty accurate for a start! This in itself is an important concept. When you purchase a 17" CRT monitor, the diagonal distance of the viewable portion of the screen can be anything from 15.5" up to over 16" - for example, the old Acorn AKF85 (actually a Philips monitor rebadged) weighs in about 15.7" yet is sold as a 17" monitor! Contrary to this, the L17A really does have a 17" viewable diagonal distance, resulting in substantially more screen real-estate. For this reason, it is best to compare the L17A with a 19" CRT.

The VideoSeven LCD monitor

The big attraction of an LCD monitor (I must stop accidentally typing LSD!!!) (I mis read this as "taking" the first time and fell off my chair -ED) is its physical dimensions. All the table top surfaces here have just over a 2 foot depth to the wall making a 17" CRT monitor the largest traditional screen possible in the available space. Indeed, even with a 17" monitor, it was tricky to get a keyboard in as well! I believe this is a problem faced by many of us - balancing the need for more screen space with physical constraints and the amount of squinting needed as higher resolutions make things smaller and smaller. The L17A panel itself is certainly very thin front to back, just 3-4 inches, but it is hampered by an overly large base which is 9-10" front to back! Still it fits nicely in the space vacated by the old 17" with room for the keyboard in front and space for extraneous cabling behind - it‘s worth commenting that connections to the panel are made vertically (ie. from the bottom upwards) so cables don‘t protrude backwards. This is a nice touch, but rather offset by the large base!

However, the single biggest difference between a traditional monitor and an LCD panel is in the way the image is produced. LCD panels are constrained by the number of physical "pixels" on the screen. Most small 15" panels are limited to 1024x768 resolution for just this reason - an often overlooked deficiency! The L17A has a native resolution of 1280x1024 which is more than acceptable. Indeed, most people will find this an ideal resolution to work in, and it displays well under RISC OS. Explan actually provide another, higher resolution of 1360x1024, although I suspect the monitor is scaling this to suit! Screen resolutions below the native one are achieved by scaling the picture, and this is often one of the most telling tests for a panel - scaling needs to be smooth and without performance impact.

Since LCD panels are made up of a fixed number of pixels (rather than the moving ray of a CRT monitor), the concept of refresh rate is almost meaningless, as a pixel will either be on or off (well, on in any number of colours!) Since the screen isn‘t being continually "redrawn" as such by the monitor, flicker is non-existent, which takes some getting used to. Since your RISC OS computer generates an analogue signal, it will still be working on a "refresh rate" system, but like frames per second in a computer game, this simply determines how smooth motion is. Explan use a refresh rate of 60Hz at each resolution, which is very sensible, and also frees up some of you‘re computer‘s performance which would otherwise be taken up by redrawing the screen all the time. It is also worth saying that as a by-product, the 56Hz required for 800x600 in 16 million colours on a RiscPC is rock steady, making that a perfectly usable mode for checking out photographic images, without eyestrain. Since a RiscPC with 2Mb of VRAM can display all the modes available on the L17A, the only advantage of extra graphics capability (such as a ViewFinder card) is in the number of colours available.

One final comment to conclude our comparison of monitor types concerns brightness and contrast. These too, tend to be different from their CRT counterparts, and the usual methods of calibrating a screen tend not to work for LCD monitors. It took me much experimentation to find good settings, although the lighting in the office doesn‘t help!

The Review Proper

Finally, you may think to yourself! However, the background to LCD panels is absolutely critical to the review of such a beast. Having been used to CRT monitors for so many years, my initial experiences of the L17A were not entirely positive - indeed I must confess to feeling a little disappointed when I first used the unit just before Christmas. My opinion has now changed, but only after extensive trial and error. Fortunately, my recommended settings are included at the end!

The LCD panel is significantly lighter than it‘s CRT counterparts, but I would suggest slightly more fragile. It came in a sizeable box, although nothing compared with the huge 19"+ CRT boxes that grace the local computer store! As usual, there was the appropriate PC driver disc, wall mount fixtures and a surprisingly useful manual indicating how to set it up, and attach cables etc. Explan had thoughtfully added in some RISC OS instructions and a disc with an appropriate monitor file (more on this later). They also made rather a fuss over the cable used. I won‘t bore you with the rigmarole, but suffice to say that you will need to know which machine you intend to use the panel on before you order it from Explan, as the panel is very cable-sensitive (this is a problem which equally affects PC owners, I‘m told!). As far as my experiences were concerned, I simply attached the monitor using the supplied cable, followed Explan‘s instructions, and low and behold, it all worked first time.

Screen modes

LCD panels are capable of auto-adjusting to cope with the screen mode being used, and remembering this setup. Anyone who has struggled to make CRT monitors display the picture in the correct place on the screen will adore this feature. You need to pick it from the panel‘s simple menu, and the screen will judder into position. Once complete, the setting will be saved, and your desktop will fill the available area and no more. Very nice!

My default desktop resolution is now 1360x1024 which, whilst beyond the native pixel resolution of the panel, seems perfectly usable, and the extra screen area is most welcome. The scaling when moving between resolutions is excellent, coping well with potential problems such as text rendering. Whilst it isn‘t necessary to change screen resolution very often when working in the Desktop, it can be helpful when you need to check things in more colours. The big test for the resolution handling of the panel came when running games or a PC card, which often require unusual modes. This proved to be a major stumbling block initially, as Explan had clearly not considered the more diverse usage of machines when creating the Monitor Definition File, with 640x480 being the lowest supported resolution!

I have subsequently spent the time adding extra screen modes with !MakeModes, and now all the games I‘ve tested display correctly, although low resolutions appear letterboxed. Because LCD monitors are more sensitive to mode timings, it isn‘t possible to artificially pop them up to full screen, a trick used by GameOn and the like for CRT monitors. No matter - anyone with a DVD player will be more than familiar with the charms of letterboxing, as will most readers using the standard screen definitions supplied with RISC OS machines. I have submitted this updated Monitor Definition File to Explan, and I believe that new customers will receive a version of this as standard, solving the problem. Once suitably updated, the panel has been perfectly happy running Heroes of Might and Magic 2, Doom, Quake and some of the old Krisalis titles. (And one or two "in-development" bits and pieces...!).


One common problem with LCD panels is that of "ghosting" - a delay in reacting to changes on the screen. I have to say that the L17A does suffer from this when dragging windows around rapidly, although not in any way which affects usability. For example, if I now drag the window I‘m typing into around the screen at speed, it will suffer "motion blur" effects, a bit like "pointer trails" on certain other operating systems. However, one has to ask how often you suddenly start madly moving windows all of the place! The simple answer is "you don‘t very often" and since there is no screen corruption, this is a very minor thing. Indeed, I had to think long and hard as to whether I even mentioned it at all! With it‘s VRAM caching, I suspect RISC OS 4 may not help on this either, as dragging windows around on a CRT monitor can give a little trail! It is, perhaps, worth adding that when testing games on the panel, the expected ghosting didn‘t appear. I had anticipated the panel being almost unusable for most games, but in fact there are no complaints on that score.

Viewable Angles

One of the most hotly discussed features of LCD panels is that of viewing angle. With some panels, looking from oblique angles can radically distort colour perception, and even render the screen unreadable, either due to light reflection or contrast problems. The L17A doesn‘t appear to suffer at all in this regard, although it is advised that you be looking at the screen square on when adjusting brightness/contrast as there is some minor variation at extreme angles, but nothing which would affect use.

Solid Colour Areas

Whilst beginning to sound like a PC labs tester, another good test for any screen (or printer) is to display solid areas of colour, especially mid-greys, blues, reds etc. Whilst there‘s no problem with a plain white blank document window, for example, a large grey Draw rectangle does exhibit slight vertical banding. Similarly, if you remove the backdrop tile from the desktop, the resulting grey is similarly affected. It is by no means serious - having just removed the background now, I have to look for the effect to see it. Certainly, the L17A performs much better in this regard than other LCD panels that I have seen, but it isn‘t perfect, but what is? As a side note, this "sold colour" test is somewhat artificial, as it is very rare to have large blocks of the same colour. The moment you apply a texture (eg. Filer windows) then the problem is gone.


You may be thinking that sound is a rather odd category to asses a screen on, but the L17A includes a pair of stereo speakers just below the screen. Whilst these are not going to set hi-fi enthusiasts‘ ears alight, they are a major improvement over the rather poor inbuilt speaker found in most RISC OS machines. My initial inclination (having tried monitor speakers before) was to set the volume to maximum and do my best to ignore the distortion that this inevitably brings. You can imagine my surprise when I discovered that a setting of 20 (less than 2/3rds of maximum) was more than loud enough (many people will want 15 or less) resulting in much less distortion. Whilst no match for expensive speakers, the sound produced certainly beats the £15 "multimedia" speakers from PC World and the like! The 3W per channel rating once more proves how ridiculous such measures are for speakers - Mhz processor speeds, anyone?!!

Tweaking the Panel

As I said earlier, my initial experiences with the panel weren‘t 100% favourable, and it is thanks to a number of tweaks that my opinion has changed. It is worth saying that the lighting here is not at all suited to LCD panels, being provided by fluorescent strips a few foot above the computers. However, the first thing to note is that as supplied you will probably find the monitor excessively bright, a trick the manufacturers use to get round the fact that its contrast/brightness range isn‘t as broad as other models in the same range. By supplying it set similarly to other models, potential customers viewing the whole range won‘t notice differences, but when set up at home, you may well find yourself suffering the kind of eyestrain normally associated with flickery low refresh rates on CRT monitors!

My current contrast is 25, whilst my brightness setting is just 4! I find that this gives a balanced display which I can use for hours on end without much eyestrain. Additionally, some lower resolutions initially appeared jumpy, as if the monitor definition file was wrong. This was cured by adjusting either the Clock or Phase settings by + or -1. I do still get a rather odd streaking effect for the first 5 seconds when turning on in the morning, but this cures itself by the time the desktop is reached. I don‘t think this is a monitor type misconfiguration, but since it sorts itself out so quickly and then works fine all day long without a hiccup, I don‘t feel it is worth worrying about.


Having used the L17A for over a month now, I can confirm that I am very impressed. What is more, the areas I expected to be weak (non-native screen resolutions, fast game graphics etc.) turned out to be almost red herrings. The key to successful use of the panel is to sort out the brightness and contrast settings for the lighting conditions in the room. Explan were quite helpful in this regard, and it‘s probably a good plan to check everything you think you know about conventional monitors in at the door before starting out with LCD panels.

One warning - when going back to traditional CRT monitors, you will find them to be flickery fishbowls (most CRT monitors have slightly curved screens), and you‘ll wonder how you managed to live with them for so long. Will I be installing L17A‘s on all the machines here? No, because my pockets aren‘t that deep, and because it‘s helpful to test things on other monitors. But with money no object..... I‘ll take two!

Product details

Product: 17" LCD Monitor
Supplier: Explan
Price: £999+VAT (£1173.82 inclusive)
Address: PO Box 32, Tavistock, Devon, Pl19 8YU
Tel: 01822 613868

Andrew Rawnsley