The older bios as it is from the older units will not work in the newer GCT's, all I got was a blank screen and no boot. Putting the newer standard bios in a older unit caused the GCT to come up just like the normal GCT in which entry into setup couldn't be obtained.
Hopefully Programmer or WildPencil have the two bios images to see if there is something that might be done to created a third bios imiage that can work in all units. One thing to note, we aren't missing a whole lot, there weren't any earth shattering options; a lot of power management options, boot options (HD cdrom network) and a few memery/PCI bus tweakings. I had hoped that the 26 pin header was a floppy and enabling the floppy controller in bios would allow adding a floppy drive to the GCT but there was not mention of any floppy drive in bios at all (like the i-Opener) some of the PCI and memory options might allow a little speed increase.
I am going to contact Gateway support or try contacting the service center in Texas that I dug up many threads back and contact them directly (when I find spare time) to see if there is just a wierd key press that allows entry into setup. Since Gateway has discontinued these units, you would think that they might be more open about it!
FYI - The easy way to tell if a GCT has the older "friendly" bios is that when booting up the older unit displyed the boot logo with Gateway & AOL logo, the newer one only shows the bigger Gateway only logo. After the Instant AOL starts then you see the dual logo on both units.