QUOTE(shambles1980 @ Apr 28 2012, 02:11 PM)
but some of the x2 bioses work ok, and the x3
Nearly...
You can't run X3 BIOSes on a TSOP, or an any chip that isn't an X3. If you flash an X3 BIOS to a TSOP you need to fit a chip, or use a 29-wire mod, or remove the TSOP and flash it externally.
QUOTE(shambles1980 @ Apr 28 2012, 02:11 PM)
its also possible to just leave the wires connected and simply run from the 1st 256k.
...
have you tried to unground a19?
could let you boot to a situation where you can flash. or to a point where you can Soft mod then flash..
all depends on the flash configuration on the chip though
The 3-wire trick doesn't quite work like that. All wires floating (i.e. disconnected) means that all banks on the TSOP have to contain the same BIOS, because the boot code checks that, so disconnecting A19 doesn't work if the TSOP contains different BIOSes.
You have to have A18 and A19 either grounded or connected to +3.3V in order to select a specific 256k or 512k bank:
- If A19 is connected to ground then the xbox only sees half of the 1MB tsop chip which is 512kB in size
- If A19 is connected to 3.3v then the xbox only sees the other half of the 1MB chip which is 512kB in size
The example above will get you going if 2 banks is enough and would require only one switch. If you want to have 4 banks then while you have A19 connected to either ground or 3.3v and it only sees one half of the chip you have to also connect A18:
- If you connect A18 to ground the xbox will only see half of that 512kB bank which is 256kB in size
- If you connect A18 to 3.3v the xbox will only see the other half of that 512kB bank which is 256kB in size
So:
CODE
A18 Float A18 Gnd A18 3.3v
A19 Gnd 0-512 0-256 256-512
A19 3.3V 512-1024 512-768 768-1024