Backlighting FAQ of 26-Oct-1999

Q. What is the backlight called?

The current project name for the 200LX backlight is the SCB-01.

Q. So this is a sure thing, then?

We believe so, but this should be considered a pre-announcement. Until beta testing has been completed, it is still possible that the SCB-01 will not be produced or sold. The decision to begin making and selling the SCB-01 is contingent upon successful completion of the beta testing phase; if the product is determined to be reliable and a good investment, we will begin production.

Q. When will the SCB-01 be available?

It's too soon to say, but now that we know the process works and have produced working prototypes, beta testing should commence. It is estimated that beta testing will take 2-4 weeks, so by the end of November 1999, we should be done with testing. Then SCB-01 packages can be sold. The availability of the components also affects how soon we can begin mass-producing the SCB-01 and installing it in palmtops.

Q. Can I be a beta tester?

Sorry, the beta testers have already been chosen. We will notify you if you're a beta tester.

Q. How much power will the SCB-01 use?

Depends on how much you keep it on. When operating all the time, the SCB-01 decreases battery life by about 30%. Most people won't leave it on all the time, so 10% seems like a reasonable estimate for how much it will decrease your battery life.

And, of course, the backlight has no noticeable effect on battery life unless you turn it on.

Q. Does the SCB-01 change the 200LX size or weight any?

The SCB-01 is a completely internal modification. Unless you look at the screen, you should not be able to tell the unit has been changed. The SCB-01 components will add some weight, but very little, since the lighting panel is almost paper-thin and the power circuit is very small as well.

Q. How do I turn the backlight on and off?

The SCB-01 is software-controlled. Stefan Peichl as written a custom TSR called BACKLITE.COM to control it. The program defaults to a hotkey of Fn-B to toggle the light on and off, but you can change this by following instructions in the documentation.

Mack Baggette is also adding backlight control to his doule-speed software driver SPD31, which will allow owners of speed-upgraded backlit machines to control the SCB-01 with no extra software.

Q. What if BACKLITE.COM or SPD31 gets erased?

The electrical control pin used for the SCB-01 defaults to ON when the palmtop is rebooted, so if your palmtop reboots and you don't have BACKLITE in your autoexec.bat, the light will be on and you won't be able to turn it off. There will be instructions for writing and executing a short debug session that will allow you to turn it off (and back on if desired) should this occur, but you should re-install BACKLITE or SPD31 as soon as possible. (And even more so in the case of SPD31, since without it, some double-speed palmtops have illegible screens.)

Q. How does the palmtop look without the backlight on?

Great! As good as a stock palmtop, in my opinion. The screen has a bit of a colored tint to it; somewhat pink or gold, depending on the lighting. To me, contrast is just as good as a normal palmtop, although some people prefer the original look. Whichever you prefer, the new look is perfectly usable. Some versions may have a more limited angle-of-view than the origial screen.

Q. Will the SCB-01 work with upgraded palmtops?

All known palmtop upgrades are compatible with the SCB-01. This includes the 4MB upgrade, the 8MB upgrade, the 32MB upgrade, the 64MB upgrade, the 96MB upgrade, and the speed upgrade.

Q. How bright is the light?

Decently bright. It's not bright enough to illuminate the keyboard, but works well for viewing the screen.

Q. What color is the light?

Currently we use a blue EL panel, which, when filtered through the screen and the polarizers, looks pretty similar to an Indiglo wristwatch's green-blue light. We are experimenting with other colors, especially white, but these take more power.

Q. Does the SCB-01 help out in dim light?

Depends on how dim it is. In light that is adequate for seeing the screen normally, the backlight can hardly be seen. If the ambient light is too bright and you turn on the backlight, the screen will seem to invert. The reason:

The reflective aluminum sticker on a stock palmtop has been replaced with a transflective polarizer that allows the backlight to shine through, but also reflects light so you can see the screen when the palmtop is off. Unfortunately, when the light shining through the back of the film is brighter than ambient light (which occurs pretty much any time when it's dark and you turn on the backlight) the screen appears to invert; black pixels become white and white pixels become black. (Well, since the light is blue, the black pixels actually become blue. But you get the idea.)

To compensate for this and make the screen look normal, BACKLITE automatically inverts the screen when the backlight is on. 1 But if the ambient light is stronger than the backlight, the screen will not appear to have inverted in the first place, and so, to the user, it will appear that the screen is inverted and the backlight is off.

The point being, if you use the SCB-01 when the surrounding light is too bright, it won't work, and the screen will look inverted to boot.

Q. Is the process of installing the SCB-01 in my palmtop dangerous?

Everything is dangerous, but with proper training and precautions we are confident that failure rates will be very low. The SCB-01 and future models are probably the most complicated palmtop upgrades in existence, however, so obviously they involves a certain amount of risk. Fortunately for palmtop users, we have done the testing for you, and have destroyed all the palmtops necessary, learning from our mistakes and working out a virtually foolproof process for installing backlights. Our palmtops have not died in vain. :)

Q. What will the SCB-01 cost?

It's too early to tell for certain, but end-user cost is expected to be under $200.

Q. If I don't like the SCB-01, can my palmtop be restored to its original condition?

No. Once a screen is upgraded, it cannot be restored to factory condition. You can, however, have your backlit screen swapped out for an original screen, for a nominal fee (yet to be determined).

Q. Will the backlight element used by the SCB-01 eventually burn out?

The EL panel used is expected to last for 5,000+ hours of running time before fading and wearing out. Using the backlight three hours a day, which is probably more than most people will use, this translates to over 4.5 years of use. When it does fade, your palmtop can be sent back for replacing the EL panel for a fee (yet to be determined).

Q. Are there any restrictions to using PCMCIA cards or other high-drain devices while the backlight is on?

The SCB-01 draws power from the PCMCIA port, to a maximum of about 18ma. This should pose no problems for PCMCIA cards that draw up to 150ma. Some higher-drain PCMCIA cards that shouldn't work in your LX, but you use them anyway, may pose a problem. Future versions of the SCB-01 may use a different power source.

Q. Who will sell and install the SCB-01?

Thaddeus Computing will sell and install the SCB-01.

Q. Are any other features planned for future versions?

Future versions of the SCB-01 may include installation of a power jack and the ability to plug in an external inverter, which would significantly increase backlight brightness. Future versions may also include a hardware on/off switch, different colors, and lower power usage.

Q. Who can I contact if I have any other questions?

Send e-mail to if you have any other questions.

Thaddeus Computing has begun taking names and e-mail addresses of people interested in purchasing a backlight when it becomes available. To be added to the list, send a message to Please don't send technical questions to this address; Thaddeus has no more information than is posted in this FAQ. Also, please do not call Thaddeus regarding the SCB-01 until the product is actually announced.


1. A future version of BACKLITE will include the option to disable automatic screen inversion, as some people may prefer the blue-letters-on-black-background look.

Copyright 1999, Palmtop Information Central.
Last Updated 26-Oct-1999