X1900 XT wouldnt flash bios, now theres no video signal

And you flashed it the first time... why?

Ok, the system is most likely still booting. I hope you have your system to boot from the floppy first. What you need to do is get the original BIOS file, put it on a bootable floppy (on another PC of course because you can't see what you are doing on the one you are referring to) with ATIFlash and all the necessary files that go along with that.

Next, create a file called autoexec.txt and put the following line in it:

atiflash.exe -f -p 0 bios.rom -scansii

Make sure you replace bios.rom with whatever the BIOS file is called. Next rename the file to autoexec.bat and if it asks to replace, do it. Then stick the floppy in the PC with the x1900xt and turn it on. Wait for a minute or two to make sure it's done then reboot. It should work now.

Wow!!! Sounds like you've done that before?

I wrote a guide on how to do it, both editing and flashing for nvidia and ATI cards.

EDIT: Oh, and yes I've done it before  

Ah **** it didnt work this is what I have in my autoexec.bat file.
atiflash.exe -f -p 0 Sapphire.X1900XT.512.Samsung11_051221.bin -scansii

is your PC booting from the floppy first? If not, then it won't work. You could pull the power on every other drive in the system so it can only boot from the floppy, that should work.