What is flashing and taping and why is it needed?

[poiihy]

I hear a lot about "flashing" and "taping" of graphics cards in the forum.
I think I know what flashing is, it's when you replace the firmware of a PC graphics card with the Mac version so you can use in Mac, but I'd like some more info of this. And why is there a different card for Mac or PC? Is it because Mac uses OpenFirmware and PC uses BIOS?
Taping is when you put a piece of tape on a pin(s) of the graphics card so it doesn't make contact, but why do you need to tape it?
Also, can someone make a list of all the graphics cards that can be used in PPC Macs?

 

[MagicBoy]

Flashing - correct. They make different Mac and PC versions for a couple of reasons, 1) to save end users from flashing their own cards 2) PowerMacs used proprietary ADC ports for cinema displays for a while. The manufacturers would usually prefer the firmware and tools don't go public.

Taping - Apple used AGP pins 3 and 11 for ADC signals. Wintel PC makers later used then for a different purpose - faster AGP 8x. The two are not compatible, taping them up insulates the connectors and runs the card in AGP 4x mode.

 

[poiihy]

What cards work in PPC Macs and what cards do and don't need to be taped? All cards that are not 8x don't need to be taped?