@Kazuma
The TC514258AP are 256Kx4 bit - so with 8 of them its 1MB
The D424402V is a little troublesome but I havepinned them down to 4Mx1 thus with 8 of them you have 4MB - now there is a little more info for the the D424402V -
NEC JAPAN
D424402V-70
9130FU004
These particular chips are Static Column enabled - which means in a device that can utilize this feature - like an A3000 then it will improve memory efficenty (transfers / refresh) by about 10%
However if the A3000 is equipped with an 040 - I dont think you can take advantage of the SC enabled memory - but I am not 100% sure - Andy would be able to tell you more on that