What is max IIe RAM? 24meg possible? ;-)
perl...@cnsvax.uwec.edu
Apple II (not IIgs) system..
The Applied Engineering memory boards can hold 4 or more megs of RAM
(RamFactor III or similar?) and fit on one slot...
What if we put, oh, SIX 4-meg memory boards into the Apple II? Could the system
handle having 24megs of memory in it? What exactly is the maximum RAM the
system can handle? *wild grin*
Just vaguely curious..
Hey, using 24,576K of RAM might allow some pretty interesting things to be
done using that system.. the "multi-media Apple IIe" ;-)
==Record and play a 30-minute soundtrack using those cassette port digitizers..
==Watch extremely LOW Quicktime movies using the 80x48 double-low res mode,
using four levels of gray.. 40 minutes worth of space at 10fps..
==Put all your old games in a RAM disk; never use your floppies (or Hard drive
for that matter) again!
Any other possiblities? ;-)
-Kris
Soenke Behrens
<perl...@cnsvax.uwec.edu> wrote:
>Just a minor question for those hardware gurus out there who know the normal
>Apple II (not IIgs) system..
>The Applied Engineering memory boards can hold 4 or more megs of RAM
>(RamFactor III or similar?) and fit on one slot...
>What if we put, oh, SIX 4-meg memory boards into the Apple II? Could the system
>handle having 24megs of memory in it? What exactly is the maximum RAM the
>system can handle? *wild grin*
If you designed it that way, it could. The maximum physical memory range of
a 65C02 is 64k. Everything beyond that is accessed by "bank-switching" in
relatively small amounts of memory (<= 64k). Actually <, since you need some
code to stay where it is (like OS, parts of the current program, I/O switches,
etc.). So, yes, you could build a 24MB card. And it would be near useless:
Slow, and too much mem for such a small machine, anyway.
Soenke
Eric Veum
greg berigan
considering adding more memory on it. I remember the documentation
claiming up to 16 MB of memory with piggyback boards, but I fear that
that is no longer possible. Currently it is populated with 64K on the
card (and 64K on the motherboard of course) and is not accelerated.
Any help out there?
--
gber...@cse.unl.edu (Greg Berigan)
Be articulate! Your new patience will not show up immediately.
Randy Shackelford
greg berigan <gber...@cse.unl.edu> wrote:
>I have a RamWorks II (yes, two, not three) in my Apple //e and am
>considering adding more memory on it. I remember the documentation
>claiming up to 16 MB of memory with piggyback boards, but I fear that
>that is no longer possible. Currently it is populated with 64K on the
>card (and 64K on the motherboard of course) and is not accelerated.
AE used to say 16 mb since the design of the hardware could support that much
but I don't think they ever sold addon cards bigger than 2 mb for a maximum
of 3 mb. If the hype about AE's imminent demise that I've read over in the
comp.sys.mac groups is true, none of this stuff will be available much longer.
That's humorous when you recall ads in the old Apple II mags saying stuff like
"don't buy memory today from a company that may be a memory tomorrow." I have
a RAMworks II in my //e with three sets of 256K chips and a set of 64K for a
total of 832K, so the machine has 896K overall. Plus a 1 mb RAMfactor for
RAM disk action.
--
Randy Shackelford "That's right, keep dancing
sh...@crash.cts.com on the minefield"
-Al Bundy
Jonathan Pratt
> Just a minor question for those hardware gurus out there who know the normal
> Apple II (not IIgs) system..
>
> The Applied Engineering memory boards can hold 4 or more megs of RAM
> (RamFactor III or similar?) and fit on one slot...
Never actually used one myself but most s/w (including ProDOS) only
actually looks for one RAM card, beginning with slot 3, then from 7 to 1.
You may have to actually write your own software for multiple cards.
(dunno what comes with RamFactor)
Theoretically, there's no real limit on the amount of memory you have in a
][ system, but you need to be able to address it. For a non //e (aux
slot) memory card, the info is usualy addressed by bank switching blocks
of 16 K in the same way as the language card use to do. (Titan cards were
like this - they had multiple banks of 16k to give 32k, 64k or 128k of
total expansion RAM)
The //e (aux slot) cards were a little bit easier to use since they
actually switched blocks of 64k which can be addressed using the built in
soft switches. (you can address various parts of the auxillary RAM with
the soft switches). For cards larger than 64k, you merely have another
location (and there were two that were most popular) which switches
between banks of 64k. If the location held 00, then the bottom 64 k
(though it doesn't matter) was addressed, an 01 was the next bank, and so
on until the whole card was accessed (1meg = 16 {$00-$0F} banks).
relatively simple...
If you want to build your own card, get a couple of 16meg SIMMS and attach
them to a card. All you need now is some memory refresh, address decoding
and bank select (buffer) circuitry. Stick your card in the aux slot of
the //e and you've got as much RAM as you can afford. Just gotta write
the software for it. Not unless you have many other cards, or an aweful
lot of RAM will power consumption or heat dissipation become a major
consideration.
cheers
ntt@cleese
David E A Wilson
>Never actually used one myself but most s/w (including ProDOS) only
>actually looks for one RAM card, beginning with slot 3, then from 7 to 1.
>You may have to actually write your own software for multiple cards.
>(dunno what comes with RamFactor)
ProDOS would have no problem with 6 standard slot RAMcards (Apple 1MB, Cirtech
or RamFactor) as they are just Smartport devices. ProDOS only uses the first
bank in an Aux slot card (you need a custom driver to access the rest).
Appleworks can use some Aux slot cards itself.
>If you want to build your own card, get a couple of 16meg SIMMS and attach
>them to a card. All you need now is some memory refresh, address decoding
>and bank select (buffer) circuitry. Stick your card in the aux slot of
>the //e and you've got as much RAM as you can afford. Just gotta write
>the software for it. Not unless you have many other cards, or an aweful
>lot of RAM will power consumption or heat dissipation become a major
>consideration.
Don't forget to add circuitry so that video only comes from the 1st bank
of aux memory otherwise your 80 col and double hires displays will look
awful each time you access another bank.
Randy Shackelford
Jonathan Pratt <n...@cleese.apana.org.au> wrote:
>Theoretically, there's no real limit on the amount of memory you have in a
>][ system, but you need to be able to address it. For a non //e (aux
>slot) memory card, the info is usualy addressed by bank switching blocks
>of 16 K in the same way as the language card use to do. (Titan cards were
>like this - they had multiple banks of 16k to give 32k, 64k or 128k of
>total expansion RAM)
Slinky cards like RAMFactor and the Apple II Memory Exp. Card give you access
to one byte at a time. You set a three byte address in the card's workspace
and call a firmware routine and you get back the contents of the byte at the
address and the address gets incremented for the next call. You write to memory
in a similar way. So these cards have a theoretical limit of 16 mb.
>The //e (aux slot) cards were a little bit easier to use since they
>actually switched blocks of 64k which can be addressed using the built in
>soft switches. (you can address various parts of the auxillary RAM with
>the soft switches). For cards larger than 64k, you merely have another
>location (and there were two that were most popular) which switches
>between banks of 64k. If the location held 00, then the bottom 64 k
>(though it doesn't matter) was addressed, an 01 was the next bank, and so
>on until the whole card was accessed (1meg = 16 {$00-$0F} banks).
>relatively simple...
These cards have a bank select switch generally located at $C073 which selects
a 64K bank. The selected bank is accessed and behaves in exactly the same way
as the only aux bank in a 128K machine. This scheme also gives a maximum of 16
mb.