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From: cssu@cdfb.utoronto (Tak Ariga)
Newsgroups: comp.sys.apple
Subject: Re:  APPLE ][+ MEMORY
Message-ID: <8705211153.AA25400@cdfb.toronto.edu>
Date: Thu, 21-May-87 07:53:23 EDT
Article-I.D.: cdfb.8705211153.AA25400
Posted: Thu May 21 07:53:23 1987
Date-Received: Sat, 23-May-87 13:49:05 EDT
Sender: daemon@ucbvax.BERKELEY.EDU
Distribution: world
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Lines: 48

> From: Henry_Chiavaroli.WBST129UL@xerox.com
>
> I HAVE AN ][+ WHICH I WOULD LIKE TO EXPAND TO 128K.
>
> FIRST, IS THIS POSSIBLE?

Well, it is possible to add more memory to a //+, but it will NOT allow
you to run programs designed for the //e or //c with 128K.  The reason
for this is that the memory is managed in totally different ways.

In a //+, you would be adding a RAM card, which usually is 128K, and it
works on the bank-switching principle.  It switches the memory in
banks of 16K, which resides in the top 16K above your 48K on your mother
board.  So, you would have 172K, but "really" only using 64K of it any
given instance...

In a //e and //c, 128K is managed by having a "mirror image" of the 64K
in another bank.  So, again, switching is involved, but it switches
in 2 banks of 64K each.

Anyway, I hope you can see that they manage memory in vastly different
ways.

Another reason you can't run 128K //e or //c software on a //+, is
because of a lot of other hardware differences, like the way 80 col.
is handled, double hi-res graphics, the CPU, and a few other things,
so it's not just the amount of memory.

You won't be able to run //e or //c software, but adding memory to a //+
comes in handy as a RAM disk, or expands your Appleworks desktop, or
something else...  So, it's fairly worthwhile if you can get a RAM card
cheaply.

> AND SECOND, HOW?

Just buy a RAM card, and drop it in an empty slot...  Fairly straightforward.

If you have any futher questions or anything, feel free to contact me.

--Tak

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