Technical Specifications for the BeBox

I/O Devices

GeekPort

The "GeekPort" is a new feature connector unique to the BeBox. It provides digital and analog I/O and D.C. power through a 37-pin connector at the back of the chassis. This port is aimed at experimenters and small entrepreneurs so that they may bring unique functions to the BeBox. The GeekPort is located on the ISA bus and can be accessed by the CPU, a PCI busmaster card, or an ISA busmaster card.

The GeekPort has the following features:

• 2 Bidirectional Data Ports Each 8-bit port may be independently configured as input only, or output with readback. This allows the user to configure the GeekPort as 16 inputs, 8 inputs and 8 outputs, or 16 outputs. The data ports are protected against shorts to power or ground.
  
  
• 4 A/D Pins Each of the 4 pins can be routed to a high-quality 12-bit A/D converter. An analog signal ground reference pin is provided. The data A/D pins are protected against shorts to power or ground.
  
  
• 4 D/A Pins Each D/A pin is connected to an independent 8-bit D/A converter. An analog signal ground reference pin is provided. The data D/A pins are protected against shorts to power or ground.
  
  
• 11 Power and Grounds 2 pins at +5 V, and 1 pin each of +12 V and -12 V are provided. The power pins are protected by fuses on the main processor board. 7 ground pins are provided. The shell of the connector is connected to chassis ground for shielding.
  
  
• GeekPort Connector A 37-pin female D-shell connector was selected to best meet the requirements of experimenters, due to the following features:
  
  
  • High Pin Count 37 Pins allows for plenty of signal pins and adequate power and grounds.
    
    
  • Readily Available The connector is listed in most electronics catalogs, and is available in most shops that cater to the experimenter.
    
    
  • Mechanically Robust The shell of the connector is rugged, and the pin spacing is large enough for inexperienced assemblers to solder connections to the pins. The large size of the connector will allow many types of devices to be built onto the connector itself or onto a small PCB directly connected to the connector, or within a standard backshell.
    
    
  • Not Standard on PCs This connector is not commonly used on PCs so the risk of plugging an incompatible device into the connector is greatly reduced. Even if a user accidentally attempts to connect a smaller connector, the large size of the GeekPort connector prevents more than a few pins near the end from making contact. The power connections have specifically been grouped to the center of the connector to help prevent the accidental shorting between the power pins of the GeekPort to external cables and devices.

Technical Documentation for the GeekPort

• GeekPort Pin Description.
• The DAC component manual.
• The ADC component manual.
• Pin signal info from the BeBox manual.

In order to assist with the porting of Linux to the BeBox, Be Inc made available (to Will Sowerbutt) some proprietry documentation about the GeekPort. That information is now available here:

The first document is marked "Be Inc. Confidential", and is hand annotated in parts. The document is titled "GeekPort", revision 0.4. Higher resolution copies of this documentation are available on request.

[Page 1], [Page 2], [Page 3], [Page 4], [Page 5], [Page 6], [Page 7], [Page 8], [Page 9], [Page 10], [Page 11], [Page 12], [Page 13]

Further documentation about the GeekPort Analogue-Digital Converter was also released. This also is marked "Be Inc. Confidential", and is hand annotated in parts. This document is titled "GeekPort A-D Converter", initial revision 0, dated 13/12/1994. Higher resolution copies of this documentation are available on request.

[Page 1], [Page 2], [Page 3], [Page 4]

Kasumi provides a programmable interface and low-level state machine for programming and controlling the MAX186, making the interface for the software driver simple and efficient. Internal Be Inc documentation titled "Kasumi Address Decodes and registers" (undated) is also available below. Again, higher resolution copies of this document are available on request.

[Page 1]

GeekPort Source Code

Below are some selected source files from the BeOS Kernel that relate to the GeekPort:

• Analogue to Digital and Joystick drivers
• Digital to Analogue driver
• Driver for the digital i/o portion of the GeekPort
• Definitions for using the GeekPort

Further GeekPort Information

• Joseph Palmer explains about GeekPort Data Rates
• Information about Projects using the GeekPort

 Questions? Comments? Contact Andrew Lampert (webmaster at bebox dot nu).

© 1998-2009 Andrew Lampert