As far as memory goes (both ROM and RAM), they're nearly always following some JEDEC standard thus pinout and operation will be same as most other memories.
For other types of chips there's no such kind of standardisation besides 74 and 4000 series logic chips.

Hmm, I think i'm missing something right now.

Let's take this: http://pdf.datasheetcatalog.com/datasheet/All … tor/mXrqqxt.pdf (Found it in previously described way, going to be upgrades for CL5446 gfx)

It doesn't say anything specific about JEDEC standard except packaging... which is 40pin SOJ.

What am i missing?

That's a standard 16bit wide 256Kbit sized DRAM, other DRAMs with such arrangement have same pinout and work same way and are direct substitutes.

Tiido wrote:

That's a standard 16bit wide 256Kbit sized DRAM, other DRAMs with such arrangement have same pinout and work same way and are direct substitutes.

I've used terms like "256k dram" (and then scanned through datasheets, to get the correct stuff) to find possible options. Is this the best way to do it, or is there maybe some kind of library, where i could maybe even input this example chip and it shows all the alternatives?

There are databooks with listings of part names from various manufacturers but I haven't actually taken any closer looks at them. I tend to exhaust my stash before even thinking of tring to buy new/compatible chips when I would need to know alternative part numbers.