I found a usb light (about the width of a pen, about an inch long) for $1 and couldn't pass it up. I got out my miniusb-usb adaptor and plugged it into my calc. Once you plug it in, it turns on and freezes the calc for 3 seconds. After the 3 seconds, the light goes out and you can use the calc again. In DCS, it stays on for about 8 seconds.

Is there any way to have it both light up and still be able to use the calc?

And why does it stay on longer in DCS?

I believe the reason it turns off is that the calc realizes the light is overdrawing from the usb port and disables it. No idea why it lasts longer under DCS though...

My guess is the same reason the I/O port locks up the calc when you plug in a pair of headphones. The OS tries to 'talk' to the USB device, and when it gets no response, disables it. But thats just my guess

Oh. I was hoping I had an easy alternative to backlighting.

Haha, thanks, guys.

Either way, regardless of whether it's Kllrnohj or me that's correct, you're screwed.

What a coincidence! My friend built a USB light last night for the calc

I ordered a new calc so I am going to test it once I get it.

Is a PS/2 light possible?

Absolutely! The PS/2 port gives quite dependable 5v, even on a calc.

Why not make one for the Ucalc? That+backlight would be totally pwnsome.

Wouldn't you Just need to make a driver for it?

I beleive ammount of power is the issue here.

This could be solved with a driver, but if power is the issue than calc modding is the only option.

my friend says that he uses msd8x to get his to work, try that!

I wonder, how about adding a USB port straight on to the batteries for power only (I don't know how much would be drawn though). This could be done on any calc also.

Meh, is that true? Back when I used Omnicalc, I remember a certain function (going along with Play()) that kept the calc from freezind checking I/O port.

Ah, but USB != I/O. I/O is handled by an interrupt, while USB is a hook (I think?).

you should be able to very easily write a simple driver using USB8x that just sends power to the port.

Definitely, but you need to make sure the port is capable of safely delivering the current the light needs (I can't imagine it's more than 100-200mA).

well they said it already powers it fine until it stops.....

yeah, it powers it fine. And as soon as it goes out, I can turn the calc off and back on real fast and it still lasts just as long. I did it several times in a row and it seemed to be powered fine.