Re: Improve Video Counter???

["John Van Winkle" <appleiieman@charter.net>]

I think that was well said Michael.  An original Apple IIe to me
means.......
Original.



"Michael J. Mahon" <mjmahon@aol.com> wrote in message
20041015031446.26518.00002283@mb-m03.aol.com">news:20041015031446.26518.00002283@mb-m03.aol.com...
> aiiadict@gmail.com  (Rich J.) replied:
>
> >mjmahon@aol.com (Michael J. Mahon) wrote in message
> >news:<20041014173425.25357.00001280@mb-m22.aol.com>...
> >>> This is beginning to sound like a very non-Apple II machine...
> >
> >How about a card:
> >
> >monitor acces to video RAM area, put data
> >to a VGA monitor.  Watch the address bus and
> >look for writes/ reads to $2000-$6000 for HGR
> >and modify a VGA cards RAM buffer to reflect
> >on screen what pixel has been modified.
> >
> >To make any new graphics system backwards compatible
> >with 40/80/HGR/DHGR modes you are going to have
> >to include hardware or software to provide these modes.
>
> This is almost exactly what the SecondSight card did,
> or attempted to do.
>
> To emulate all those modes, which sort of "fell out" of the
> clever Apple II design, required a microprocessor and a
> fair amount of firmware, which seems never to have been
> completely debugged.  ;-(
>
> >VGA seems like a good option because it has a TEXT
> >mode and cards are CHEAP.  Software written in CC65
> >could be made to used to use the higher resolution,
> >but I don't think anyone would be updating currently
> >available software to use higher resolutions.
>
> The VGA controller is cheap, but making it emulate the
> standard Apple video modes requires a microcontroller
> and firmware, complicating things immensely.
>
> >Would it be possible to cut up an Apple IIe motherboard
> >and eliminate ROMS, Video circuitry?  I think so.  You
> >could use the address bus/ data bus/ peripheral bus
> >as a BARE 6502 computer, run it at any speed up to the
> >EMF and part limits, and make cards to emulate old hardware
> >features/ROMS.  I've seen many 6502 manuals and books.
> >It looks like this would be the quickest and cheapest
> >way to get a fast upgraded Apple II into development.
>
> Carving up an Apple is a poor way to get a fast, semi-modern
> 6502 system.  There are lots of much more compact and
> faster ways to go.
>
> Of course, it's a bit trickier to get a fast, semi-modern
> _Apple II_ system, since the Apple II is much more than
> another 6502 single-board computer.
>
> >With a bare 6502 BUS and slots, It seems like it would
> >be easy to watch the address lines and update a VGA
> >buffer.  1 card with all ROMS, OLD video mode, paddle,
> >disk II?, a slow 6502 for disk access, cassette etc.
>
> All the required address and data lines are available
> buffered and brought out to a connector on the peripheral
> bus.  Anyone who wants to design such a card has
> always been free to do so.
>
> Perhaps it's not as easy or attractive as you think.
>
> >new cards or maybe PCI adaptors to new hardware.
>
> Shucks, why not just a new _computer_ while we're
> at it.  ;-)
>
> I continue to press my opinion that a classic computer
> is interesting _because it's classic_, not because you
> can use it as a base for a nuclear powered time machine. ;-)
>
> Or, more to the point, if you want to design your own
> computer, feel free to do so without calling it an Apple II.
> I think that Woz did a _great_ job, including making it
> the most _natively extensible_ machine that had ever
> existed up until that time.
>
> I love my 8MHz Zip Chip (which is unobtrusive both to
> software and to the eye), my SCSI disk, and numerous
> software extensions, but I draw the line at ripping out
> large chunks of Apple II logic, emulating it in firmware,
> and then calling it an "Apple II".
>
> The wonder of the Apple II is that Woz used only a standard
> 6502 and a very small amount of simple hardware, and created
> a machine of such power and versatility that it is still quite
> interesting from both a user and an engineering perspective.
>
> A VGA card is interesting from neither point of view.  There
> is no application software to exploit it (as other than an
> emulation of standard Apple II video), so a user is unsatisfied;
> and the logical design of a VGA adapter is so over-wrought
> and expansive that there is nothing to delight an engineer.
>
> The only possible utility of such a thing would be simply
> to adapt Apple II video to a VGA display, for which it is
> monstrous overkill, and of dubious necessity in any case,
> since NTSC monitors are ubiquitous.
>
> For me, the proposition is exceedingly simple:  the only
> video modes with software support are Apple II modes,
> and that will never change.  So a VGA display will never
> look better than a "fat pixel" version of standard Apple II
> video (which I think looks worse than the real thing).
>
> If someone thinks that they can change that--realistically--
> then I'm all ears.
>
> -michael
>
> Check out parallel computing for 8-bit Apples on my
> Home page:  http://members.aol.com/MJMahon/