K4S561632D-TL75 are the RAM chips on a MP900 motherboard. There are a pair of them. I've often thought about upgrading the RAM on my machine, but it was kind of cost prohibitive 5 or 6 years ago...
But now that the chips are plentiful and not used much any more, you can find them on eBay.
I'm thinking I could pick up a couple of chips, desolder the old ones and reinstall the new ones to double my memory from what it is now.
The K4S511632D-UC75 is available on eBay now for only $5.
While it might be a fun project, I'm not sure I would really be gaining anything...what'cha think?
Keep fingers crossed because whether the RAM will double depends on the kernel. If it is not programmed to use all available memory you are doomed. There are examples of both good and bad kernels among pocket pcs.
When I tried searching for 128 MB tsop54 chips for Sigmarion I did not find anything. I now realised that I have a spare Sig motherboard to modify.
You might want to examine available datasheets to find any inconsistency between these two parts.
