More RAM!

Just to add, you can check out the flash too (be careful though as if you use the wrong address you can kill the bootloader!).

// On RHS
var adr = 0x08000000 + (512*1024) - 4; 
var f = require("STM32F1Flash");

// On LHS
>f.read(adr)                           
=4294967295
>f.unlock()
=undefined
>f.write(adr,42) 
=undefined
>f.read(adr)   
=42

So the chip I have here has 512kb of flash - TWICE AS MUCH as it's supposed to!