The HP39DIR files
You may notice separate download icons for the 38G and for the 39G, 40G and 39g+ with no mention of
the new hp 39gs and hp 40gs. This will change as the sites update the contents to reflect the new models.
In general, any aplet which is suitable for the older HP39G, HP40G or hp 39g+ will also work on the new
hp 39gs and hp 40gs. Some games may not be for two reasons. Firstly the earlier models used a slower
chip and this means the older games sometimes run so fast that they are unplayable. Secondly, some of them
directly access the calculator’s chip. If the address on the chip they reference has changed from the old
model to the newer one then running the aplet may cause the calculator to lock up or spontaneously reset.
The worst result will be loss of user memory. None of the aplets designed for the earliest model, the HP38G,
will work on older models.
If you own a calculator then you will already have the required cable with which to download from the
internet. If you bought yours second hand without a cable then you’ll need to purchase a cable from an
electronics store. The mini-USB cable required is the same as that used by many digital cameras.
Downloading an aplet from the web is very simple. Any site will present you with a page which may be
similar to the one on the previous page. It may contain either programs or aplets or both. Generally you will
be able to click on a link that lets you download that aplet as a compressed ZIP file.
A ZIP file is a special type of file which contains one or more files in compressed. The reason for the
compression is simply to allow you to download them from the Internet as one single file instead of having to
download each one of the collection separately. The ability to expand these ZIP files is built into Windows XP
and you should de-compress them as soon as you have them on your PC. Just double click on the file and it
will open as if it is a folder. You should then move or copy them into a normal folder (one that isn’t a
compressed file).
The software that sends the files to the calculator can’t work on them if they are inside a compressed file so
you
must
expand them before using them.
Calculator Tip
It is
critical
l not be harmed
l
aplet.
that you decompress each aplet into a separate directory.
Each aplet has two special files called HP39DIR.000 & HP39DIR.CUR
which always have this same name. Decompressing two aplets into the
same directory will cause these two special files from the first one to be
overwritten by those of the second. The aplet itself wil
by this but the effect is to render it invisible to the calculator, since these
two special fi es contain information telling the calculator about the
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