Hi all. Recently I purchased a sony HB-G900AP which I would like to upgrade to 1024kb.
Inside there are 4 chips TC514256P-12 and 4 empty 20pins sockets.
If I'm wright it's just a matter a filling those empty sockets to go from 512kb to 1024kb.
The only problem I have is finding the same chips.
I did find some V53C104FP70 chips which, according to the datasheet I've found, are quite similar.
But I'm not really a hardware expert, so if anyone can give me some advise it would be very welcome. Wouldn't like to blow up my nice msx finding out if they work or not

I also got a Panasonic WX which only has 64kb, so it would be nice to boost the memory of this one too. Maybe the V53C104FP70 chips are suitable for this other project too

is the same pinout but V53C104FP70 have many mode of refrech
sold socket on board and try !!

Is there no risk for damage ?

i don't think you have risk or damage just work or no work
try on WX with 2 memory and strap for 256k