I've seen on a few router pages that 64MB RAM mods are the maximum as 64Mbit x16 DDR1 chips aren't available.... well it seems they are, albeit rare. All I can find is Micron MT46V64M16 - TSOP16 64Mbit x16 DDR1 which seems to fit the bill quite well. I've found them for sale at http://www.aliexpress.com/item/disassem … 33354.html and tempted to try them. Anybody have any reasons why they might not work?
And for a much more radical idea... What about getting a pair of 32Mbit x8 chips, solder the first on the board as usual, but leave the appropriate set of data pins corresponding to one half of the x16 data pins disconnected. Then sit the second chip directly on the first and solder all the wires to the first except for the data pins. For this chip, you'll need to make a tiny bridge between the 8 data pins on this chip to the remaining unconnected 8 data lines on the PCB. If you look at the pinouts comparing x8 to x16 then you'll see that each extra pin for x16 sits one or two pins away from the 'twin' x8 pin, so in reality it might not be so hard to achieve. Thoughts?