Using this tutorial can i have my 512k tsop split + a cheapmod. And also i dont have a computer to flash the chip (i put the processor in backwards and burned a bit of it) so can it be flashed under evox from scratch. This is a bit stupid but is there any limitation to the flashrom or eprom used.

BUMP

eproms are not flashable at all in the xbox, or PC for that matter.
given that your tsop is already flashed and you install a switch and hook up the write enable points on the flashrom afterwards, yes, you can flash it in the xbox. make sure the flashrom is 90ns or faster.