Hello, A few weeks ago I ordered a Sigma 400255 for my H11A LSI-11 computer with the hopes of getting a 8" floppy hooked up for VCFMW. For the most part, all the tests I ran from the ODT seemed to be AOK. The one this I couldn't do it boot RT-11 from my TU58 emulator, as it would crash every time. Every since I was able to boot RT-11 on my machine it has been unstable and prone to crashes, but i chalked that up to the TU58 emulator, and not the machine itself. Since I needed to boot from to TU58 in order to INIT and make a bootable RT-11 disk for my system, I looked for other causes for the crashes. I ran the VKAA XXDP test, which passed fine. I then ZKMA test, which lo and behold listed back there were numerous bad addresses all over memory. The only memory modules I have are 3 nearly identical 3rd party 32KW memory modules. The one that I have in the system right now came with it, and is the one with memory errors. The other two are ones I bought on eBay that are in rather poor condition and currently do not work at all. I was hoping to transfer some of the 4116 chips from my nonfunctional units over to my semi-functional unit, but I cannot find schematics for any of the boards because they don't have any marking identifying marking on them. If anyone knows where I can find schematics for these boards, that would be wonderful. I am including a picture of one of these boards below. https://i.ibb.co/sQwZw0j/32kwram.jpg Thank You, Gavin Tersteeg