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80. Can the hp 39g+ be 'overclocked'?

Thanks to Al Borowski for the reply below:

Sure. It's kind of tied in with the emulation...

Basically, the chip inside the HP39g+ is an ARM9 processor made by Samsung, which is very powerful for a calculator. It is also used in
some other devices, like iPaqs.

The old HP39G ran a "Saturn" processor at 4MHz, while the new 39g+ runs an "ARM" at 75MHz. However the 39g+ isn't 20 times faster, because it has to pretend to be a Saturn chip so older programs will run. This is called emulation, and it wastes much of the power of the new chip. This means the 39g+ is only 2-4 times faster than the 39g. If you want to make your calculator run faster, you have 2 options:

1) Run software specifically written for the new chip. Some programs bypass this emulation layer and run directly on the ARM. Programs written like this will be many times (up to 100 times) faster then programs written for the Saturn processor. They can also do more things, like have greyscale graphics and good sound effects, or even save batteries compared to normal programs. However not many of these programs are available yet.

2) Overclock the calculator. While the ARM chip used in the HP39g+ runs at 75MHz, its can actually run much faster (up to 203MHz). It doesn't run at full speed to increase battery life. By running a special program it should be possible to increase the speed of the CPU, to make things go faster. I have written such a program for the 49g+, and it works well, but I haven't tried making one for the 39g+.

For those who are technically minded, some information may be found at the following links:

The processor in the 39g+:

Some information on ARM programmg (shameless plug)

The HP-GCC progrect, aiming to create a C compiler for the new HP calculators:

See also (thanks Tim Wessman):

and (thanks VPN): ClockSpeed Adjustment Tools - Overclock your 49G+ 2.00
Note that this one is for the 49g+ (which shares the same chip).

See also my comments about programming in HPG-CC on my Help page in the section on Programming.

81. (39G/40G only) Why have rows and columns of keys have stopped working on my HP39G or HP40G?

This is quite a common fault in the 39G and 40G. The keyboard had design issues. At our school we had a return rate of 10-20% on our 39Gs. Sometimes you can get temporary relief by gently twisting the calc longitudinally. ie around the axis running along the line [d/dx], [TAN] [8][5] etc. Don't overdo this for obvious reasons. Also obviously, you do this at your own risk!! You can also press down down (hard!) on the HP label below the middle of the screen. While you're pressing down the keys will probably work but often only while you press down. Usually once it starts occurring it will continue to recur and will infect the whole row and then possibly others. Sorry. No point in false hopes.

Is the calc still in warrantee? If so, take it back. Because this is a known issue HP are sometimes willing to replace it even outside warrantee period. They were quite good with our school. You may want to try. Don't take any crap - they know about this and you should push them to play ball. But being a big company.... :-(

Alternatively, get a 39gs or 40gs. These have great keyboards!


82. I've installed the Comms software, so why is my PC not recognising the calculator when I plug it in?

There seems to be some sort of bug in the installation routine for the Communications software. This is the software that allows you to send/receive programs, notes and aplets from the PC to the calculator or vice versa.  All peripherals (hardware devices plugged into the computer) such as printers or scanners require a driver to allow them to communicate with the computer. Think of the driver as an interpreter that allows the computer to speak to its connected devices (peripherals). On quite a few computers this driver doesn't install properly.

The symptoms of this failure to install the driver are that when you plug in your calculator the software doesn't acknowledge it - the "searching torch" image continues to be displayed, indicating that no calculator is present.  You may also find that the Windows "Found new hardware" wizard pops up as soon as you plug in the calculator.

If the "Found new hardware" wizard is showing then do the following:

bulletunselect the box in the options on the wizard's screen that tell it to look on the web, or the floppy drive or the CD/DVD drive. Instead, select the option that lets you specify a folder in which the wizard is to look for the driver.
bulletclick on the "Browse" button next to this option and direct it to look in the Drivers folder where the comms software was installed. If you've installed the software in the default location, this will be in C:\Program Files\Hewlett-Packard\USBDriver folder.
bulletClick on OK and wait while it (hopefully) does its thing. It will probably tell you that this driver is from a source that Windows doesn't recognise as being safe. Tell it to proceed anyway.

After the wizard finishes you should find that the "searching torch" will now give way to the normal image displayed when the calculator is connected correctly, which is a folder view. The comms software is now waiting for you to select a folder containing the aplets/programs/notes that you want to download, or to specify a folder into which you want to upload material from the calculator.  You can find instructions on this on my help page here.

If you're still having trouble, or if you have cancelled the wizard before reading this then try the following:

bullettry restarting Windows just in case it hasn't registered the new driver's presence.
bulletif this doesn't work, you can often get the wizard to re-appear if you unplug the calculator and then plug it in again.
bulletyou can also often provoke the wizard by using the "Add Hardware" command in the Control Panel and telling it to search for new hardware with the calculator plugged in and switched on.
bulletIf you can't get the wizard to appear, or if it didn't work then try the following:
bulletOpen the folder C:\Program Files\Hewlett-Packard\USBDriver.  You should find that it contains a file called HPx9G.inf.  This is the one you want.
bulletClick once with your right mouse button on this file. A menu should pop up with one of the options being "Install".
bulletUse your left mouse button to select this option.  Nothing will appear to happen but doing this should force the installation of the required driver. Try the comms software again. You may need to restart Windows but generally this isn't required.

If you've done all of this and you're still seeing the "searching torch" image when you run the software with the calculator plugged in then try a different USB port. The USB ports on the front of the computer are notorious for not working properly and most modern computers have multiple USB ports. Try them all.

If none of this works... Sorry.  Over the past five or six years I have run into just four computers, all laptops, that just would not work with the calculator no matter what I did. You may have one of these. If so, I can't help.

Last modified: 19 Dec 2007                                             Sitemap        Home        Contact Me