🚀 go-pugleaf

I have installed 4 MB of SIMMS in my 386DX-33 Mhz computer.
Now I get during start up sometimes a parity error and often
while I am running a program. I just saw in the documentation
that I shouldn't use NMBS DRAM. And offcourse (Murphy's Law) the
SIMMS are NMBS SIMMS. Could this be the problem? And what are
NMBS DRAM and what should I use else (the documentation only talks
about 256KB/1MB RAM modules with 70ns or 80ns propagation delay time)?

Any help would be very appreciated,

Richard