31 Dec
2008
31 Dec
'08
10:31 a.m.
On Dec 31, 2008, at 1:26 PM, bfranchuk at jetnet.ab.ca wrote:
Just don't use "PC motherboard SRAMs" as someone suggested
earlier. They're nowhere near as easy to find as some people think
they are, at least for some of us...I trashed all of my 486 boards a
decade ago. Standard, currently-available SRAMs are cheap and easy
to work with, and are just as fast. I have a few 512KB SRAMs in
SOJ-36 packages sitting on the bench right now; I think they were
about $7/ea in small quantities from a distributor.
-Dave
--
Dave McGuire
Port Charlotte, FL
As far as
pricing goes, a 4 layer board (you *really* want at
least 4 layers here) + components + assembly & test should be <
$1000. How much less I don't know. The target for my unibus
memory board is ~$500 (fully assembled & tested + some profit).
Given that this wouldn't need unibus transceivers (hideously
expensive when you can find them) I would expect this to be in the
same ball park especially if it can be contained on a quad board.
The other issue with not replacing the cache, is
that the verilog
to implement this would *much* simpler (ie it can probably be
completed faster).
TTL ... and a few gals... I trust hardware more than software is my
view point.
Real cache memory 32k*8 is about 15ns access time in a skinny 28
pin package.
I am just not sure how much memory you can get on a card
however ... Sigh.