Re: RAM cards for IIe

["Bill Garber" <willy46pa@comcast DOT net>]

"Wayne Stewart" <waynes@telus.dotnet> wrote in message
news:HepLc.104990$eO.50024@edtnps89...
: Moll wrote:
:
: > I think the docs said something about a maximum of 48 banks?
That's
: > where I got the value of 3 MB.
: >
: > Moll.
:
: Maybe because the RamWorks with daughterboard topped out at
3mb?
: When Tony Diaz was showing Prototypes at Kfest 3 or 4 years
back,
:   didn't he show a 8mb Auxiliary slot card?
:
: Wayne

I know I might say 64K when I mean 64 in some places
but this should explain it for the most part. Sorry
if my mind can see it, but my fingers can't type it.
This is the gist of it though.  :o)

First, let us recognize that 16 bits tops out at 64K, so
therefore 64K of 64K banks would allow us to go to 4MB,
and each bit that we logic out doubles our possible number
of banks we can add, so one bit above 4MB gives us 8MB,
and another bit gives us 16MB, however, this latching of
bits also increases the amount of time needed to access
these additional banks. A 1MHz system would be considerably
slower the more time needed to latch these extra bits. Of
course, an accellerated system would access them faster,
the faster we can get it to run. Theoretically, we could
have 64K of 64K of 64K banks if we so choose to, which
would allow 256MB of bank-switched ram. Good Luck. You
would be waiting forever for it to logic out which bank
you would be accessing, not to mention the cache needed
to store which bank of banks of banks had the byte you
wanted to read/write. Where would we put all the needed
hardware?, outside the machine in a separate box? Ok!

Bill @ GarberStreet Enterprizez };-)
Web Site - http://garberstreet.netfirms.com
Email - willy46pa @ comcast DOT net
Change DOT to a dot to contact me



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