I have a couple of old Samsung 30 pins. I have a feeling that they're 4Mb ones (I recall I was running 16Mb at the time and I did have 4 of them (the other two are probably sitting at the bottom of our many, many packing boxes in the mess at home)) however no idea if they even work cause they've been chucked about in boxes, dumped in drawers, carried in pockets, etc, etc. so not kept safely stored... I was thinking they may be better as keyrings after all this time...
I dunno if they'd suit a Mac. They're from an old 486DLC I bought back in 1993 (and never threw away). Samsung KMM581000A-8 - I found a
piccy of these (not mine, but the same model) on eBay in case you wanted to visually see...
The only difference it has is that it says 038 SM underneath the "KMM..." text, and the details on the squared-end says 94 V-O underneath the bell symbol.
I'm no electronics person. I figure people here would have a better idea what all that means.