On  1 Nov 98 at 19:18, Tibor Mocsar wrote:

> I have a problem that I haven't been able to solve alone. Months
> ago I assembled a 486 PC utilising old secondhand parts. The
> mainboard is a UC 4915-C AIO and it has no L2 cache. So I took the
> cache chips and tagram from an old 386 mainboard and set them in.
> But they don't work! I doublechecked the jumpersettings on the
> mainboard, the chips themselves and BIOS settings. I noticed that
> Amibios looses (or deactivates) the setting upon booting. What did
> I wrong?

  There are a couple of possibilities:

1.  The 486 boards I remember anything about have only accomodated
cache sizes of 0, 128KB, or 256KB.  The only 386 with L2 cache I ever
got my hands on had 64KB, not one of the sizes the 486s could use.

2.  RAM chips are typically sized by the number of bits they contain,
but there are several common variations in how the bits are arranged.
  A chip that is 8 bits wide by 8K long is a "64K" chip; it provides
8KB of storage, and 8 of them can be combined to make 64KB.
  A chip that is 1 bit wide by 64K long is also a "64K" chip, and you
can also make 64KB by combining 8 of them.  But one by itself doesn't
give you 8K, and your memory controller has to be hooked up
appropriately.

  Odds are good that the maker of the 486 board recommends a specific
part number for cache chips, and anything else might not work.

David G

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