|Category||» XBOX / Mod Chips|
Beacause the DuoX 3 is pre-flashed, if you don't mind the bios, just boot one of the HeXen or Slayer 3.3 boot discs and install one of the dashes (eg. EvoX). They perform exactly as an Aladdin chips.
Those chips have a bios already loaded on each of the 256kb / 2Mbit sides (49LF002B). One is for 1.0-1.5 machines and the other is 1.6a and 1.6b. This is all written on the board beside the switch. Flashbios is not loaded on either side, just the two M8 bioses that are edited (it boots up with a colored duo x3 logo).
To flash new bios get a HeXen or Slayer 3.3 boot disc ISO and burn it at 4x speed, boot your box with it and select the "Modchip/Tsop" menus. Chose "flash bios" and select the one you want. Both discs have checks for the bios and you won't be able to flash the wrong one accidentally.
For memory chips of type 49LF002B (the chips used in some Duo 3X's I would like to reflash):
- Two chunks of memory can be independently write enabled/protected at the same time.
- In order to properly reprogram the devices both chunks must be write enabled.
- This is achieved by wiring WP# (Pin 7) and TBL# (Pin 8 ) to positive 3.3 volts (Vdd).
You can just bridge pins 7 and 8 to pin 25 or 32 (both Vdd) and the 49LF002B is then fully write enabled. Leaving things in this configuration shouldn't cause any problems during normal operation.
Xbox modchips can either be flashed by the Xbox on the LPC bus, or directly via programmer, how this is supported usually depends on the CPLD (or FPGA) code.
Tthe difference between the old 49LF020A and the newer 49LF002B is the addressing mode. When programming the 49LF020A it wraps around when high address is accessed with the address lines, so if you flash a 512kb (4Mbit) BIOS into 49LF020A it will effectively be flashed twice, while SST49LF002B just give error (no wraparound). The device CPLD has to take this into account to work as expected on the Xbox LPC bus. This is also the reason you need 49LF020A to do the old classic cheapmod which is just a socket with wiring. The CPLD emulate the 49LF020A address line behavior when 49LF002B is used for Xbox software/homebrew flashing compatibility.