Re: What is the quintessential Apple II?

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

mdj wrote:
> Michael J. Mahon wrote:
>
>
> > Matt, if you want to re-enable your game port on a late mainboard II,
> > just snip one lead on C94, C95, and C96, just in front of the cassette
> > input and output jacks.  (If you feel strongly about it, snip *both*
> > leads.  ;-)
>
>
> Done :-)

Great!

> > It's too bad that they didn't provide the VBL interrupt in the //e, like
> > they did in the //c--but that's just the arrow of time.
>
>
> If that meant having the //c's oddball gameport hack to support the
> mouse and the expensive interrupt overhead, I'm happier this way :-)
> But yes, just the softswitch to enable interrupts on VBL would have
> been nice, and would save me a slot.

I coudn't agree more.  I was amazed at the //c joystick/mouse interface.
About the only thing that //c pushbutton inputs are compatible with is
pushbuttons!  ;-)  (Of course, it also has some more exotic modes, but
you can't get compatible pushbuttons.)

> > > But it's all subjective. Whichever you prefer probably depends on which
> > > Apple II 'era' you had the most exposure to, which for me was the
> > > 128k(+) enhanced IIe/IIc. I do however think it's difficult to argue
> > > that the enhanced firmware isn't a substantial improvement over what we
> > > had with the II+
> >
> > I'm especially pleased that interrupts became so much more usable.
> >
> > In the early days of the Apple ][, I think it's safe to say that Woz
> > hadn't contemplated much practical use for the IRQ.
>
>
> Yeah, that's the main one - although once you add RamWorks style memory
> you've got additional complications there.

Yes--that's what a good standard bank-switching protocol would have
fixed, but Apple never did it.  In several other cases, they "anointed"
an existing player as the "standard" and supported it in system code.
(Taxan RGB adapter and ThunderClock come to mind.)

> I really like the fact that the mini-assembler came back - it's very
> handy. The only 'missing' in the IIe firmware that the IIc had is that
> the monitor L command disassembles 65C02, but I guess given how much
> smaller the IIe ROM space is, they did a fine job squeezing in
> everything they did :-)

True, space is a real constraint.  The disassembly list function of
the Monitor is alread crammed in pretty tightly, even using data
compression.

What the List command does is intimately related to the function and
capability of the mini-assembler.  The mini-assembler is another fine
hack, in which the opcode byte is incremented successively, with the
result of dissassembling it being compared to the input line.  When
the disassembly matches the input, the correct opcode is found!

-michael

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