apple2freak{at}gmail.com wrote:
> On Mar 2, 9:26 am, mwillegal  wrote:
>> On Mar 1, 8:57 pm, adric22  wrote:
>>
>>> I wouldn't bother to update the design much, if any.  The only good
>>> reason I can think of for building such a thing would either be for
>>> nostalgia or for classroom education.  When I say education, I mean
>>> for teaching the basics of how the internals of a computer work to
>>> engineering students since the 8-bit systems like the C64 or Apple II
>>> are so much easier to understand than a modern PC.  Now, the Apple II
>>> was never my area of expertise (I'm a Commodore fanboy) but if I'm not
>>> mistaken the Apple II was designed from all off-the-shelf parts,
>>> right?   So it should be possible to still build one today with off
>>> the shelf parts.  I'm surprised nobody has come up with a new board
>>> design.
>> The Apple II reproduction has been done, though some obsolete parts
>> are hard to come by.  You can buy a kit from me.
>>
>> http://www.willegal.net/appleii/appleii-recreation.htm
>>
>> Regards,
>> Mike Willegal
> 
> Mike -- very cool.  I take it your intent was to create an exact
> replicate of the Apple II and not enhance it in any way?

Right--it's a *tribute* to the Apple II, not an enhancement.

> Regarding an enhanced IIGS -- let's call it a IIEGS to save typing --
> I have no illusions that such a thing would have any appeal except
> perhaps to a few dozen hardcore Apple enthusiasts and hardware
> experimenters.  I know there are a few people like this out there as I
> have visited their web sites and seen their postings here.

I agree that there are interested folks, but I submit that most of
them are intrigued by the prospect of using modern technology to
reproduce the Apple II (in its several versions), with or without
enhancements.  Relatively few of them are programmers just waiting
for an "enhanced" Apple II to write new suites of programs for it.

> I suspect that if any significant enhancements were made (which I
> would like to do), that the software effort would be at least as great
> as the hardware effort as well.  The GS rom code and GS/OS would need
> to be reverse engineered (thankfully modern reverse engineering tools
> like IDA Pro have reduced the effort required here significantly) and
> then updated to support new display modes and whatever other
> enhancements were added to the system.  I happen to have a copy of the
> source code for System 7.1 which may help a bit in this effort as
> well.  In fact, maybe System 7.1 could be backported to the IIEGS --
> and this project could be started on existing IIGS systems and/or
> emulators.

Actually, if any actual use were to be made of the enhanced capabilities
(instead of just running existing Apple II software), the software
effort would be *much* greater than the hardware effort.

Unless you attract a "critical mass" of software, from system software
to application software, any enhancements are purely theoretical and
for the amusement of the implementor.

> Regarding adric22's comments about there not being much point to such
> a project other than for nostalgia and/or education -- perhaps you are
> right, especially if no effort was made to update the design.
> However, there would be no educational point to re-implementing the
> design with discrete logic since for all practical purposes, they are
> no longer used in modern designs.  Someone else has already
> implemented the entire Apple II on an FPGA (see link above) as well --
> in an educational context.  I think most of the point of a IIEGS
> project would be in the pleasure that came from creating it more-or-
> less from scratch and then using it as a platform on which one could
> run old software titles along with more modern software such as mpeg
> audio players, older graphical web browsers, etc.

The educational benefit of the Apple II (un-enhanced) is its simplicity,
understandability, and easy hardware and software expandability.

It is possible for a human being to understand *exactly* what an
Apple II is doing in each and every cycle in a way that is quite
impossible for any modern machine--even for its designer!  ;-)

It is also possible to turn on the power and write a "Hello, World!"
program in a single line.

If having a backward-compatibility mode is all that makes a machine
an Apple II, then any PC or Mac with an emulator already fills the bill.

If backward-compatibility includes the ability to use the many hundreds
of peripheral cards that exist, then a 1MHz bus must be implemented, as
well.

If you want to do it because you can, I fully understand that.  But to
imagine that it would become a useful platform for others is, I think,
unlikely.

-michael

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