What are these motherboard mods?

[Ral-Clan]

Hi,

I have two revision 5 motherboard Amiga 500s. When I got them, both were pretty much identical ECS modded boards, installed with KS2.04 and fatter Agnus, OCS Denise.

But each board had a different motherboard modification done to it.  Both mods were in the vicinity of the Denise chip. One was a wire running to a transistor(?), the other was the addition of a resistor.

Here are pictures (red highlights the mod) - click on them to enlarge.





What do these mods do - and why different mods for a motherboards of the same revision?

[CritAnime]

They look like factory mods for timing and such. It confused me first time I saw something similar in a 1200. Even though 2 machines have the same version number you can see quick fixes like these done.