sun4 memory board in sun3 ?

[beaver.cs.washington.edu!wuarchive!uwm!aplcen!ginosko!cg-atla!weber at cs.utexas.edu]

The board for a 3/200 series machine is not compatible with a 3/100 based
machine.  No jumpers or other variables will make it so.  As far as I know
your 3/200 memory board will only work in 3/200's and will not work in
3/400 or 4/300 either.