Not true, I expanded a Wavy70 to 128kB long time ago -putting 64kB into the free socket- and you have to solder two memory pins between the two RAM chips and change a jumper.
I did the 512K upgrade on Wavy 35J. I don't think 70FD is a lot different. I had to remove 2x4464 dram chips and wire four 44256 chips on a small separate pcb, then use wires from IDE cable to connect all signals from original 4464 sockets and two more signals from MSX engine chip. Alexandro, MSX user from Brazil, made similar upgrade a year after me and he even documented all the process. If I'll find the link to his instruction, I'll post it here.
hi, im a spanish user.
in a two wheeks i have a wavy msx 2+, and i like upgrade to 512k.
when the msx are in my hands i'm try make a little pcb for the esasy upgrade,
but im not read portugues, are more info in english??
