The BRAILLEX EL 40 S is the first USB based display in the BRAILLEX series from F. A. Papenmeier. Contrary to other USB displays like the HandyTech Braille Star, the BRAILLEX EL 40 S is USB powered, so no extra power supply is needed anymore. However, it has no internal battery and no notetaker functionalities, so you have to combine it with at least a laptop to be able to use it. Consequently, the laptop needs to have at least one USB 1.1 port for you to be able to connect the display.
The s in EL40S stands for slimline, and that is definitely true. Dimensions are 310 x 115 x 22 mm (WxHxD) and weight is about one kilogram. There is only one USB client port on the right hand side of the display which can be used to connect it to your PC or laptop, no serial port or power adapter jacks are present. As the product label implied, 40 piezoelectric braille cells are present, each with one cursor routing key. On the left and right hand side of the routing key row, you can find one key which can be pressed either on the rear or front side, giving you four additional possible keypresses (8 if you combine them) altogether. On the front side you find the patented access bar, a simple control which can be used to generate another 8 different keypresses. You can move the access bar with your thumb(s) to the left, right, up and down. Each direction allows for two steps. For a thumb key fan like me, this concept needs a little time getting used to, but it seems quite efficient after some practice time.
The feel of the dots is very sharp. I personally do very much like that. They do however seem to be a little slow on updating compared to other displays I've used so far. Scrolling along some long text file does feel a little weird, since the display seems to manage an update only just about 3 times per second or so. This is all very subjective, since I did not really measure the time, but in direct comparison to my very old TSI PowerBraille 40, it feels as if the BRAILLEX EL 40 S is much slower. I haven't really much used any Papenmeier displays so far, and I have been told that other display do show the same effect. SO this might be very well known and perhaps not even noticeable to users of former Papenmeier displays. However, I do notice this, and I am not sure yet if I really like this. I personally would perfer if it would update just a little faster.
The driver for BRLTTY has just been implemented mostly by Dave Mielke in the BRLTTY subbversion repository. It should be included in the next stable release (most probably 3.6). It was tested on Linux and OpenBSD. THis display is in fact the first USB display we've got working on the OpenBSD platform.
The fact that no extra power supply is required is a real relief since it doesn't add one more of those nearly indistinguishable AC adapters to your collection. Additionally, you don't have to carry such a thing around with you whenever you take your display on a ride.
However, the slim in slimline is only going to help you really if you plan to carry the EL40S between two or more stationary computers. If you want to use it in combination with a laptop you will need some extra stuff to make the laptop actually fit on top of the display. Remember that its dimentions are only 110 mm from front to back, so you have only about 5 cm space to actually place something on top of it which is obvious far too small for anything like a laptop or even a small keyboard. Note that This "thing" is apparently included with the product if you buy it, but as I only got the display for a relatively short test period, the necessary stuff to combine it with a laptop wasn't given to me so I can not really describe this in more detail. What it all means in the end however is that you have to artifically enlarge the display to be able to really nicely combine it with a laptop.