Well... you need to do 2 more things apart from the installing of the ram chips. You need to find JP2 close to the top of the ROM chip and cut the trace between the middle and the lower of the 3 pads and instead jumper the middle with the top pad. Next you need to find JP7a next to the internal mem/clock port and cut the trace between the middle and the lower of the 3 pads... that's it. If you prefer you can use a 2pol switch to change back to 512K ram in case a game refuse to work.
As someone else said you don't need to install the ramchips if you don't want to, instead you can just use a standard 501 mem upgrade card or alike and the same "hack" above will change the slowram of these cards into chipram (no the ram on these cards are NOT fastram contrary to what someone here said but chipram that's been given a different adress witch turns it into slowram. The hack will not slowdown you machine, just turn the extra mem into chipmem). :-D
