GeoBook Cheat Page: Fundamental techniques

This section describes a number of basic tricks which are required to apply some of the more specific modifications listed in the rest of the text.

Entering DOS mode

Like all other current Geos-based devices, the GeoBook contains a DOS compatible operating system which handles the bootstrap process and parts of the file system. Even though the GeoBook has not been specifically designed to run DOS applications, it can sometimes be useful to disable the Geos UI and access the underlying file system directly.

To get a DOS prompt, follow these steps:

From the Main Menu, go to the File Manager.
Type Ctrl-U twice (or use the F drive icon) to go the root of the F: drive.
Double-click on COMMAND.COM.

Now you should see the ROM-DOS command prompt. While in DOS mode, C: is a small ROM-based boot partition, D: a 512k RAM drive, which is mostly used for temporary storage, E: represents a PC memory card (if any), while F: refers to the built-in 1MB flash disk.

There are a few things to keep in mind while in DOS mode:

To return to Geos, enter the EXIT command.
When you first enter the DOS mode, the video system is still in graphics mode (a good indication for this is usually the lack of a flashing cursor). Some DOS applications (e.g. QEdit, my favorite text editor) do not like like this too much, so it may be necessary to install a utility to switch video modes from the command line if you want to experiment with using DOS programs. This here is a small one I wrote just for this purpose.
Pressing Ctrl-Alt-Del hangs the system. Don't know why.
Accessing drive E: when there is no PC card inserted gives you a "write protected" error message which is sometimes quite hard to get rid of. Try avoiding this drive entirely unless you are using a memory card.

[Brian Walz wrote:] And, if you are into it, the Geobook makes a great Infocom platform. Downloaded a DOS Infocom interpreter, transfered my games to the flash disk, and I play those games when I have some free time to burn.

Recovering from failed experiments

Another way to get to DOS mode (shows just how compatible ROM-DOS tries to be) is to press F8 a few seconds after the device first beeps at power-up. This allows you to step through the startup files line by line. You can confirm ("Y") any line until you come to "geos". A "no" reply there takes you to DOS mode even before Geos starts. If you screwed up your system real badly, you can use this to get back in and, for example, restore a backup copy of the GEOS.INI file (see below).

Editing the GEOS.INI file

Again, a lesson to learn from other Geos devices: the key to "serious customization" as well as to grave unhappiness lies in the GEOS.INI configuration file, which holds most of the settings made under Preferences, as well as a lot of options not accessible from there.

The configuration information is stored as an ASCII text file named GEOS.INI which is located in the \GEOWORKS directory on drive F (built-in Flash). The format of the file is fairly straightforward and very similar to INI on other platforms (namely the big "W" thing):

        [section name]
        key1 = value1
        key2 = value2
         :

The section name usually specifies the application or system module which is affected by the options listed below it. The order of the various sections in the file as well as that of the various keys within a section does not matter. Any line starting with a ";" is considered a comment (that is, ignored).

To edit the GEOS.INI file, you can either install a DOS mode text editor on the device itself, or you can copy the file to a disk using the File Manager, edit it on a PC and then copy it back to its original location. Anyway, you should use the DOS mode command COPY to load the modified version back onto the device. This makes sure that the settings are all re-read when Geos starts up after copying and avoids problems that can result from Geos keeping the file open while it is running.

A few things to keep in mind when experimenting with the GEOS.INI file:

Remember that the GEOS.INI file on the GeoBook is not intended for end-user modifications, so you will find purely cosmetical settings there right next to options which may even prevent the device from starting up at all.
Section headings or keys which are not understood by the system or one of its applications do not cause any error messages. Instead, they are simply ignored, so if your changes have no effect, it may simply be a typo.
If a certain key is not present in the GEOS.INI file on drive F, the system also looks for it in the ROM-based copy on drive C which contains the factory defaults.
As long as you keep a backup of a working version with your personal settings (or you are ready to copy the ROM version from C:\GEOWORKS reverting everything to factory defaults), you can use a recovery procedure to get back to DOS mode and restore the GEOS.INI file even if you have locked yourself out of Geos.

Personalizing your GeoBook

If you want to add a "personal touch" to your GeoBook, you can do so by specifying your own string for the title of the Main Menu screen. This string is specified by the title key in the [MAIN MENU] section of the GEOS.INI file.

Invoking the self-running demo

All the machines of the GeoBook series contain a self-running demo which is intended for presentation in the shops, usually with a colorful display stand attached to the case.

To start the demo, go to the Main Menu, press Ctrl-D, and sit back.
The demo can be terminated at any time by pressing F3.