Macintosh IIsi solder ram replacement

[zezba9000]

Hi, I have a couple IIsi systems (4 actually).
I'm trying to validate and source/buy some new modules for these systems but I'm hoping someone can help me confirm I'm getting the right thing.

I saw this post here that suggests the system can actually handle higher compacity (which is probably easier to source)

Upgrading IIsi onboard RAM to 4MB

The Mac IIsi motherboard is wired for a 1 MB onboard RAM array using eight 256kx4 DRAM chips or a 4 MB RAM array using eight 1Mx4 chips. After discovering this on my broken IIsi, I was able to simply replace the eight RAM chips with larger 1Mx4 RAMs (e.g. KM44C1000, M5M44400, MT4C4001) and get 4...

tinkerdifferent.com

I see some modules listed here: https://www.knjn.com/ShopMemories.html

But I normally have never sourced parts for custom solder jobs like this and want to make sure I'm getting the right thing. Any suggestions or known modules I can buy that work?

 

[ObeyDaleks]

Those look correct based on the article you linked, but personally I wouldn't buy from a site like this since there's a high likelihood of receiving fake ICs.

What I would do is to look on eBay for 72-pin RAM SIMMs (72-pin being the most economical since they are usually cheap) that have those specific ICs. The ICs are usually not described in the listing, so you might have to zoom in on pictures to see if those are correct.

Here's an example: Link

By the way, those last two letters don't matter (e.g. AJ, BJ, CJ) since those are revisions.