This section describes ways of attaching various standard and non-standard add-ons to the GeoBook to expand its capabilities.

Connecting a ZIP or JAZ drive

To reduce manufacturing cost and the number of moving parts in the device, the GeoBook comes without a built-in hard disk. For this reason, a lot of people have discussed the possibility of attaching a mass-storage device to the parallel port, which is the fastest external interface that is readily accessible.

It is possible to use an Iomega ZIP drive with the Geobook, even though it requires a little tinkering at first. A brief test I made seems to indicate that the modified drivers also work with the external parallel version of the Iomega JAZ drive, resulting in up to 1GB (!) of mass storage.

In principle, the GeoBook hardware is compatible with the Nibble Mode driver of the parallel port ZIP drive. The only thing that does not work with the standard driver provided by Iomega is the automatic detection of the parallel port, so a little patch for the ZIP floppy is needed. The GEOBZIP.ZIP package (8k) contains the necessary instructions and tools to make this modification.

You can now start the GUEST.EXE program from the patched ZIP driver floppy by double-clicking on its icon in the File Manager. Geos will now shut down and restart after loading the driver. You should now have a new drive named G, which corresponds to your ZIP drive.

Remember that GUEST will not be loaded automatically after you turn on the GeoBook, so you have to start it again yourself whenever you want to use your ZIP drive. To avoid having to carry around the driver floppy with you all the time, you can of course copy the files GUEST.EXE, GUEST.INI, ASPIPPM1.SYS and NIBBLE.ILM to your F drive and start Guest from there.

Anther thing to remember is that installing the ZIP driver will take away almost 30k of precious "Conventional Memory" from Geos, which may have an adverse impact on the system's performance. If possible, you shold remove the ZIP driver before running memory intensive applications like the Web browser, by turning the device off and on again.

I noticed that the GeoBook occasionally fails to "wake up" a ZIP drive that has gone to sleep (the motor stopped spinning, and the drive is all quiet) and reacts as if there was no medium inserted. In theses cases, it helped to eject and re-insert the medium the make the drive spin up again.

Flash Memory Cards

[Thanks to Kelly Bergen for some info on this.]

Even though Brother recommends against it, it seems technically possible to run at least some other flash cards with the GeoBook. For the following brands I have either seen them work myself or received reports of them being compatible:

Don't take my word for it - if you want to be on the safe side, Brother's own cards are probably the best bet, but if you have access to other card types, it may be worth giving them a try.

[Brian Walz provided the following information:]

"Unable to find the Brother memory cards, I was looking into other options. When I bought my digital camera, it came with a 4mb Compact Flash card. I very soon upgraded to a 32mb card and so had the 4mb card lying around. One day I was at Best Buy and noticed they had an adapter for $12 that you could slide a compact flash card into it and use it as a type 2 memory card. So, I bought it and plugged the HP 4mb compact flash card into it, plugged that into my Geobook, and it worked just fine. Then, feeling adventurous, I plugged the 32mb card into the adapter, plugged that into my Geobook, and that also worked fine.

"I have a Compact Flash reader on my PC, so I now can transfer files back and forth between my Geobook and my PC very easily. And, I never have to worry about storage space ever again.

"The adapter is a Sandisk Compact Flash adapter. Got mine at BestBuy for $12.

"The 4MB memory card is an HP card that came with my digital camera.

"The 32MB card is a PNY card, once again bought at BestBuy."

Modifying the CONFIG.SYS and AUTOEXEC.BAT files [NB-80C only]

While the CONFIG.SYS and AUTOEXEC.BAT files on the SPN-9000GR and the NB-60 cannot be modified because they are in ROM (i.e. the whole startup sequence up to the point where Geos starts interpreting the GEOS.INI cannot be changed by any means), the NB-80C allows adding commands to Flash-based versions of these files.

You will usually want to do this if you have a special device driver (e.g. for a ZIP drive, a parallel port network adapter or some other "exotic" add-on) which you want to be loaded into memory whenever you turn on your GeoBook.

To check if this feature is available on your unit, go to DOS mode and enter the following commands to list the contents of the ROM-based files:

        type c:\config.sys
        type c:\autoexec.bat
If you find the line
in your CONFIG.SYS file, you can use a text editor to add new commands (e.g. device drivers) to a file named CONFIG.SYS in the root directory of the F drive. Its contents are interpreted in addition to the contents of the copy on drive C. By default, it is empty except for a REM line.

A line similar to

in AUTOEXEC.BAT indicates the capability of executing commands in a file by the name on drive F. These commands are exectued immediately before Geos is launched. If you create such a file, you can decide whether the unit automatically "falls through" to Geos after executing the startup sequence by setting the value of the DOS_ONLY environment variable in the command file:

By adding the line

        SET DOS_ONLY=''
you keep the default behavior which is loading Geos on startup. Note the two quotation marks, which are required by an... err... somewhat unusualy batch file coding style on the side of Brother. It is possible that this is fixed on later versions of the ROM, which would lead to not touching DOS_ONLY at all being the right way to get the desired effect.

On the other hand, settings DOS_ONLY to something else, like

would keep Geos from running after the startup files have been executed.

In my own AUTOEXEC.BAT I call the modeco80 utility to make sure Geos returns to text mode when exiting, and I load the guest driver for the ZIP drive. After that, I let the unit go to Geos from where I can call COMMAND.COM when I need a DOS prompt. Of course, any drivers have to be installed on the F drive in order for them to be available at startup.