apple2freak{at}gmail.com wrote:
> On Mar 3, 3:37 pm, "Michael J. Mahon"  wrote:
>> apple2fr...{at}gmail.com wrote:
>>> On Mar 2, 9:26 am, mwillegal  wrote:
>>>> On Mar 1, 8:57 pm, adric22  wrote:
>> 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.
>>
> I see how this could go either way.
> 
> Most of the "enhanced capabilities" would relate to providing some of
> the same conveniences that you can presently obtain by running an
> emulator.  Namely, the ability to use a modern display, modern disk
> drives (disguised so as to appear as some older well-supported piece
> of hardware like the omnidisk), and of course the ability to run at
> considerably higher processor speeds.  These enhancements need not
> require any changes to the operating system.

True.  I would characterize these as "implementation enhancements"
rather than "architectural enhancements", and they are of the same
character as adding peripheral cards or accelerators.

> Supporting additional (higher-resolution) graphics modes is an example
> of an enhancement that would require significant software support.
> Exactly how much is not really clear to me right now.

If the Second Sight card is any indication, the effort is considerable.

>> 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.
>>
> I would say that the ability to use a modern flat panel display would
> be mighty convenient over an old-fashioned TV or monitor -- especially
> a color variant with lousy dot-pitch alignment.  Similarly, it would
> be awfully convenient to be able to use a compact flash card or a SATA
> hard drive and have it show up as (a SCSI drive in the case of the GS,
> or a bank of omnidisks in the case of the II).  I realize the latter
> enhancement is already available as a card for existing Apple II
> hardware.
> 
> Beyond these sorts of convenience enhancements, I agree with you that
> any further enhancements would be for the amusement of the
> implementer.

Not only is the CFFA card a new "standard" for Apple II's, there
are a couple of *fully compatible* VGA video cards becoming available.

I agree with you that these are very desirable cards, and I prefer
to plug them into a real Apple II (along with numerous other cards).

>> 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!  ;-)
>>
> I agree.  The same statement can be made about an Apple II-series
> machine implemented on an FPGA.

True, provided that it is a gate-for-gate implementation, but I doubt
that would be the case.  The minimal level of integration of an Apple II
contributes to being able to tap or probe almost every significant
signal, and though this capability decreases as you move from the ][+ to
the IIgs, I still find it quite useful.

One of the greatest barriers to understanding and experimentation with
modern electronics is that it has shrunk to a single epoxy-blobbed
die, rendering it completely "closed".

I suppose that one could make an FPGA-based system-on-chip
implementation that would be supported by great user-accessible
tools (necessarily hosted on a modern machine) which, in total,
could be as friendly and inviting to experimentation as the
original TTL Apple II, but that interface and tool chain would
itself be a major part of the project.

>> 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.
>>
> Well, here's what I'd like -- maybe you know of a better way for me to
> get it:
> 
> A replica Apple II-series machine (preferably either a IIe or a IIGS)
> with the following features:
> 
> +  VGA output (even better digital video)
> +  Built in floppy emulation using compact flash cards or USB memory
> sticks
> +  Built in hard disk (omnidisk or SCSI) emulation using compact flash
> cards or USB memory sticks
> +  Cycle-exact emulation of the original hardware
> +  Capability to run the CPU at higher-than-original speeds
> +  Emulates popular/useful plug-in cards such as the Mockingboard,
> SCSI cards, Uthernet, etc.

I agree that this would be an interesting system for many.

But what on your list is not satisfied by an emulator?  Cycle-exact
emulation is easily simulated as regards timing and video subsystem,
but is not directly observable without real-time devices to interact
with, like a Disk ][, A/D peripheral card, or annunciator outputs and
pushbutton inputs.

If peripheral cards cannot be plugged in, then you may as well adapt
an Apple II keyboard (for the physical experience) to a PC or Mac and
feed it to an emulator!

To the extent that any new implementation is a "black box" from the
point of view of an interested user, and does not implement all the
standard electrical interfaces to the outside world, it cannot be
distinguished from an emulator.

> The ability to use existing cards is not important if they can  be
> easily emulated.

That will be difficult if you have to reverse-engineer each one.

History suggests that only a few of the most popular cards will ever
be emulated, and there were hundreds of them--some quite interesting,
like 68008 coprocessors.

> Some emulators provide nearly all of these features, except for the
> fact that they require a modern PC or Mac running a disgustingly
> bloated operating system which requires constant maintenance and which
> invariably leads the user to run a plethora of applications in
> parallel which leads inevitably to attention deficit disorder!

The latter sounds like a discipline problem, for which other solutions
are much more appropriate (and valuable in the real world).  ;-)

Similarly, your distaste with modern systems and their endemic bloat
is something that I can appreciate--when I choose to.  But we must all
learn to cope with modernity when necessity or convenience dictates.
That is an attitudinal adjustment that is necessary if a respect for
parsimony and craft is to live alongside Windows (or MacOS) and cars
with 173 microprocessors!

But surely you must see that an FPGA represents the triumph of
*hardware* bloatware--using LUTs in place of simple gates, and with
a gate-level complexity fully a factor of ten greater than any system
you are hoping to emulate!

The fact that Moore's "Law" has made the prodigious waste of hardware
economical does not alter the fact that it uses hugely more transistors
to accomplish *anything* than an implementation based on simple gates.

I suggest that if you can ignore the mind-boggling waste of an FPGA
implementation, ignoring the hundreds of DLLs required just to display
an "x" on the screen of a modern computer is a similar perceptual feat.

>> 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.
>>
> True -- if you want to be able to use old peripheral cards -- I don't
> see the point if they can be easily emulated.

Just because it's conceptually easy doesn't make it actually easy, nor
does it make it happen...  And what about that rare card I just bought
on eBay last week?  ;-)

These are the reasons that I prefer (mostly) to use a real Apple //e
with a CFFA and accelerator.  I use an emulator when I need to generate
lots of (virtually) printed output or when I'm away from my real system.

>> 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.
>>
> I certainly don't imagine it would become a useful platform to anyone
> other than the sorts of people who spend their time reading csa2.  And
> then useful only in the context of entertainment although perhaps, for
> those who may enjoy working with reconfigurable hardware, there would
> be an educational aspect as well.
 >
> I gather from your home page that you enjoy tinkering with the
> hardware as well!

Yes, I do!  I particularly like pushing the limits of what the original
hardware can do, with the right software and, occasionally, a little
hardware assist.  (Adding a full peer-to-peer network function like
NadaNet required adding two transistors, for example.  ;-)

In my book, the spirit of Woz was always doing something astonishing
with practically nothing but cleverness.  ;-)

> I myself like what Alex & Steve have done over at www.applelogic.org
> and look forward to tinkering with their IIe system as soon as I
> assemble the necessary hardware to put it together.

I find the CarteBlanche idea very appealing.  The ability to design
a new card, move the output file to an Apple II, and then use it to
dynamically reconfigure a card to become whatever card you like is
a very interesting prospect.

If an "Apple II peripheral card" toolkit and user interface could
be made so that creating a new card was as easy as putting together
Tinkertoys, that would be outstanding!

-michael

******** Note new website URL ********

NadaNet and AppleCrate II for Apple II parallel computing!
Home page:  http://home.comcast.net/~mjmahon/

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