The tech screen can be found on the central command ( HQ ) screen.
Tech levels do not represent research. Your race already knows what all the
various parts are and how to use them. Buying tech represents the buying of an
infrastructure that will allow you to manufacture the part. If you are able to
capture a part from another race that is beyond your tech level you can still
mount the part on a ship and use it. If you capture an enemy ship plan you must
have a hull tech level that is high enough before you can build it.
Tech is universal. If you buy a new tech level all your bases can manufacture
items of that tech at once.
The cost of each tech level varies wildly from device type to device type and
from level to level. As a general rule of thumb; the cost of going to a higher
tech level that just gives you a small improvement on an existing technology is
much cheaper than a big leap to a completely different style of technology.
The weapon information pad will display the upgrade tech costs of weapons and ship parts.
If the persistent upgrades switch is on the orders to upgrade does not reset
after a successful upgrade. Next turn you will continue to see all the
currently selected upgrade requests still selected.