DWL-900AP+/800AP+/810+ firmware checksum calculator

Saturday January 26th, 2008 by Acinonyx

Firmware Modification Instructions

  • Unarj some_firmware.bin (is actually an arj archive)
  • Modify NML.MEM image
  • Arj NML.MEM back to some_firmware.bin
  • Pad zeros to end of some_firmware.bin until it reaches size 0xe0000
  • Copy hardware version string starting at address 0xdffe0
  • Compile dwl_checksum.c:
    • gcc -o dwl_checksum dwl_checksum.c
  • Calculate 32bit checksum:
    • dwl_checksum < some_firmware.bin
  • Copy 32bit checksum (lsbyte to msbyte) at address 0xdfffc




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GL2422MP modification for controling TX power

Tuesday September 5th, 2006 by Acinonyx

With this modification you will be able to control the power output of any device that uses GL2422MP miniPCI wireless card in a range from -13 to 17dbm on AP mode and -11 to 19dbm on the other modes. Some devices that use Global Sun’s GL2422MP miniPCI is D-link DWL-810+, DWL-800AP+ and DWL-900AP+.

Power output of GL2422MP is control by a TI (TNETW1100B) chipset. The chipset is driving various voltages on MAX2820 transceiver’s pin (TX_GC) which controls the amplitude of the transmited signal. By altering the TI’s Digital to Analog Converter operation range, we can change the range of the output power to fit our needs (see Datasheet MAX2820). In order to do this, we can simply modify the voltage divider connected to TI’s TX Gain Control output pin which converts the output current of the DAC into input voltage for MAX2820. Placing a potentiometer in parallel with the resistor between Vcc supply voltage and Vtx_gc we can control the power output of  GL2422MP without  having to remove any SMD components thus we don’t destroy the device. If we wish to rebuild the device to its original operation we can simply remove the potentiometer and it will work the same way as it did before the modification. Read the rest of this entry »

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