"Just what is an Add-on Board?"

Well, it is a board that is installed inside the Zipit and gives us several improvements over a stock unit:
  • Adds RS232 Serial Port.
  • Adds an MMC card for storage / bootup.
  • Adds an EL Backlight power supply.
  • Allows easy updating of the Flash memory contents.

  • TopRS232 Serial Port

    First benefit, the serial port. With it you can now use either the 802.11b WiFi or RS232 to pass data in & out of the Zipit. This is not the type of serial port that you would use to connect to an external modem. There are only three signals on this serial port: TXD (transmit data), RXD (receive data), and Ground (common). However, this is not a TTL or CMOS voltage levels that are used here, but good old RS232. You can connect the Zipit directly to your computer by plugging it into the computer serial port.

    This serial port is how we update the Flash memory (see below).

    TopMMC card for storage

    Once we get "our" linux inside the Zipit, we quickly find out that there isn't much room at all inside that 2 Megabytes of Flash Memory. So, the MMC socket allows us to use these cheap camera NAND Flash memories to greatly boost the file space. Having a removeable "hard drive" in the Zipit, you can easily move data in or out of the Zipit.

    Just a note to allay your fears and confusions, I did say "MMC" and not "SD", didn't I? Well, let me explain: Yes, you can use either the miniature MMC or SD card in this socket. No, you may not encrypt the data on the SD card, this socket is not capable of allowing that type of special electrical wiring and use. However, you can use an SD card as a plain old MMC card and it works just fine!

    TopEL Backlight power supply

    This probably generates me more email than anything else, people want someone to install the EL Backlight itself. Well, I decline to offer to do this for them with the explanation that it takes several hours to add the actual backlight. Labor costs and for the price of that labor, you can buy a cheap Zaurus PDA on ebay!

    Having that said, the Add-on Board does have the necessary EL power supply on it, and it will be tested to ensure that it works. YOU will have to be the one to do any addition of an EL Backlight. I do give you a tested supply on the Add-on board.

    TopUpdating of the Flash memory

    In my opinion, this is one of the most exciting, and empowering, aspects of choosing the Add-on Board! You may now safely replace the contents of the Flash memory without fear of bricking the unit. If you mess something up; you can simply do it over again!

    The miniUSB (Type B) connector has the necessary RS232 signals for uploading a new kernel image and filesystem. This connector also has the DEBUG signal there so that you can ground that wire and place the Zipit CPU into a download (external programming) mode.

    With the serial port + DEBUG signal, you can now build and customize your own linux kernel and filesystem (use the buildroot to do this). Or, you can take someone else's images and put those into your Zipit.