In regards to maximum allowable ram on some systems- my Dell 166/66 has a 
max of 64 MB.
Here is a page from the on line specs:

>NOTES: After June 1996, systems with 256-KB cache have cache installed 
>directly on the system board and are not upgradable (no cache card 
>connector or cache upgrade sockets). Systems with 512-KB cache use a 
>512-KB cache card.

>When Intel Pentium chip sets (FX, VX, HX, TX) increase the system memory 
>size above 64 MB, the system slows down. The problem is the cache limits 
>of the chip set. The second-level (L2) cache can store (cache) memory only 
>for accesses made in the lower 64 MB of main memory due to the size of the 
>cache tag. If more than 64 MB is installed in the system, any memory 
>access to data above the 64 MB is not cached. The system runs cacheless 
>for memory accesses. The Microsoft® Windows® operating system uses pages 
>of memory throughout the entire memory space so some accesses fall above 
>the 64-MB region, which causes a decrease in performance. In effect, 
>instead of getting a performance gain for adding more memory to a base 
>64-MB system, in many instances the performance is slower.
>Additionally, many games that use MS-DOS® extenders are loaded at the top 
>of the memory space so all accesses to the code are cacheless.


Mary Zimlich

                Curious about the people moderating your
                   messages? Visit our staff web site:
                     http://nospin.com/pc/staff.html