Re: What do I do next?

[dempson@actrix.gen.nz (David Empson)]

Byron Desnoyers Winmill <wbdesnoy@acs5.acs.ucalgary.ca> wrote:

> David Empson (dempson@actrix.gen.nz) wrote:
> : The "standard" 80 column card has 1 KB of RAM, 
> : The "extended" 80 column card has 64 KB of RAM.
> 
> So which was the most popular of the two, and by what margin?

When the IIe was first released, you could buy the bare machine (64 KB),
and either type of 80-column card was optional.  The extended one was
considerably more expensive.  (As I didn't buy my first Apple II until
the IIgs was released, I don't know the exact figures.)

In the early days, I expect that a lot of schools would have purchased
bare machines, or machines with the standard 80-column card, but would
have forgone the extended 80-column card.

At a later stage, I'd expect the extended 80-column cards to have been
purchased with the machine, because of an increasing amount of software
which required 128 KB, or was impractical to use without it: AppleWorks
would have been a major influencing factor here.

I suspect that a lot of 64 KB or 65 KB machines would also have been
upgraded to 128 KB over time, so I'd expect the majority of IIes to have
at least 128 KB by now.  (Don't forget the RamWorks and similar
multi-bank auxiliary slot RAM cards; these are a functional superset of
the extended 80-column card.)

> Also, why wasn't 128kB standard by the time of the Platinum IIe?

I think it was - the miniaturised 64 KB RAM card was installed in the
auxiliary slot as standard on all machines that I saw, giving a total of
128 KB.

> Sure there were 128kB cards, but they didn't seem well supported.

Oh - you mean 128 KB auxiliary slot cards?  They weren't very common,
and weren't widely supported (compared to the larger cards like the
RamWorks).

A 128 KB (or larger) auxiliary slot card requires an additional
bank-switching mechanism, which is proprietary to the card.  (Most of
them used a bank select register at $C071 or $C073.)  The extra banks
were not supported by the firmware or operating systems without
third-party patches.

I doubt that Apple would have considered it worthwhile to include a 128
KB auxiliary slot RAM card, because if they supplied it with the
machine, they would have to support it, which would have meant releasing
a major update to ProDOS as well as firmware changes.

The firmware in the platinum IIe was identical to the enhanced IIe, and
I expect that one of the design goals was to minimise redevelopment
costs, at the same time allowing for a machine which was cheaper to
produce.  Having to redevelop the firmware and operating system (with
subsequent bug fixes) would have gone against this trend.

The multi-bank auxiliary slot mechanism also goes against Apple's other
memory expansion options for the 8-bit machines, which were designed
around a standard slot with a narrow memory interface and address
register in the I/O space, i.e. the Apple II Memory Expansion Card and
the corresponding card for the IIc.

The standard slot RAM cards had technical advantages over the auxiliary
slot mechanism, the primary ones being that you can boot from them, and
the card has a firmware ROM which provides a ProDOS driver, allowing it
to work with ProDOS-8 and Pascal 1.3.

The multi-bank cards are generally harder to work with for data storage,
because of the added complexity of the IIe memory map being replicated
in each bank (with a "language card" in the $D000-$FFFF area).  By
comparison, the standard slot cards have a linear address space (up to
16 MB, but the RamFactor was probably the only card which approached
this limit).

The most significant advantage of the multi-bank auxiliary slot cards is
that you can execute code directly from them (not possible with the
standard slot cards).

-- 
David Empson
dempson@actrix.gen.nz