Re: Apple][+ RAM Card - How figure out total RAM ?

["Michael J. Mahon" <mjmahon@aol.com>]

myoldmac.net wrote:
> On Mar 12, 5:01 am, "William Garber" <willy4...@garberstreet.com>
> wrote:
>
> > "Michael J. Mahon" <mjma...@aol.com> wrote in message9f2dnRW1JJFFM2nYnZ2dnUVZ_u2mnZ2d@comcast.com...:">news:9f2dnRW1JJFFM2nYnZ2dnUVZ_u2mnZ2d@comcast.com...: myoldmac.net wrote:
> >
> > : > Hello,
> > : >
> > : > I have a language card installed into my Apple ][ Europlus.
> > : > There are no notes about any RAM on it,
> > : > but I can use a test program that finds RAM on the card to test.
> > : > The program did not tell me any size of RAM.
> > : >
> > : > Because I have also a language Card with 16 Kbyte extra RAM in the
> > : > shed I like to know:
> > : >
> > : > How many RAM is actually present on my Apple ][ Europlus ?
> > : > Is there a way to get this information?
> > :
> > : If it has a 16-wire ribbon cable jumper
> > : to the main board RAM area, you can be
> > : almost certain that it is 16KB.
> >
> > If it has this cable, then more than likely
> > it also has an extra 4116 to dispell the one
> > on the motherboard that is removed to install
> > the cable into.
> >
> > William Garber
> > Email Address - willy4...@garberstreet.com
> > Alt. Email - willy4...@comcast.net
> > Web address -http://www.garberstreet.com
>
>
>
> Dear Michael,
>
> thank you, I have this cable on the card and counted the modules on
> the card - it seems that I have a 16Kbyte RAM Card.
>
> Dear William,
>
> right - there is an extra 4116 on the card.
>
> But let me ask in general - for what is this language card used?
> Is it a special version of RAM ?

The 16KB card was designed by Apple to allow bank-switching RAM
to overlay the built-in ROM space, which increases the amount of
directly addressable to 60KB, with an additional 4KB of sub-bank-
switched RAM (the 4KB from $C000..$CFFF is reserved for I/O).

This creates what is referred to as a 64KB Apple II that can run
ProDOS, Pascal, and many applications that can utilize the additional
RAM space.  There are DOS versions that relocate themselves into the
space of the 16K card, leaving additional memory under $C000 for BASIC
to use.

Look up the documentation for the card on the web for additional
information on how to control the bank switching and write enabling
if you want to use it from your own machine language programs.

Although the 16K card (originally called the Language Card, since it
was sold with Pascal and allowed the machine to more easily support
languages other than BASIC) was developed for the Apple ][ and ][+,
it became a _de facto_ standard, so when the //e and subsequent
Apple II's were designed, the native 64KB was mapped in exactly the
same way as the 16K card.

-michael

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