Hello all,

I'm trying to find a way to get 128KB in my Sony HB F1XV. The idea is to put an extra 64KB parallel to the main memory already available, disconnect the the pin 16 of the new IC's and connect it to /CS2 on the MSX Engine (pin 45). Sort of the same mod as on the NMS8220 as described here:

www.msxarchive.nl/pub/msx/mirrors/msx2.com/hansoranje/64kxtranms8220.pdf

But this would seem too easy hm? ... Also, I don't have a datasheet of the machine and there is another IC which seems to handle memory too, it's the 'Sony MB670836' (a square block resembling the MSX engine) Googling displays no results on this IC, any ideas what this thing does?

Thanks,
Gerrit

if your Sony have a mapper inside you can upgrade memory else buy a expand memory cartridge