Re: RFC : SOME IDEAS FOR THE APPLE II FPGA'ers

["mdj" <mdj.mdj@gmail.com>]

Michael J. Mahon wrote:

> And, though you've described some characteristics of a solution that
> you prefer, you haven't shared what your *objective* is--from which
> those requirements are derived.
>
>  From what you've said, I'm having a hard time understanding why
> you aren't satisfied with a real Apple II.  It would seem to satisfy
> all the characteristics you describe, is inexpensive, reliable, and
> generally easy to fix.  The only thing that doesn't get you is the
> fun of playing with FPGAs.  ;-)

Sorry, I thought my objective was implied. Essentially what I'm
interested in is preservation. I am, in essence, satisfied with my real
Apple II, however, several of it's components are now extremely
difficult to replace, should they bite the dust. Despite several years
of searching, I've not found an 8Mhz Zip Chip to replace my Transwarp,
and the RGB adapter module on the back of my RamWorks III isn't exactly
an easy to locate item. Ideally, I'd like to be able to put these items
away and not use them. The SCSI card too, is a hard to replace item,
although GSE-Reactive make take care of this soon. It's likely though,
that I'll switch to a more convenient form of mass storage. I'm also
rather attached to my Workstation card, which allows me to mount
fileshares from my main computer (A linux box which runs Netatalk, the
Apple IIe is connected to the household network via an Asante ethernet
adapter). Despite the modest speed, it is by far the most convenient
way to transport data back and forward from the IIe I've found, since
it's the only one AFAIK that integrates seamlessly into the ProDOS 8
environment. (with the exception that ProSEL utilities, which are among
my Apple II favorites, tend to utilise low level ProDOS calls which
aren't supported by the AppleShare protocol)

Being realistic, a lot of these devices are unlikely to still be in
operating order in 20 years. It's a credit to Apple and Applied
Engineering that they all work perfectly now. Over time, I've had RAM
chips go bad on the RamWorks, one on the Transwarp (that was tricky to
find let me tell you, it was in the bank that caches auxiliary ram
cards).

So at a minimum, what I'd *like* is a replacement motherboard for my
IIe that includes accelerator functionality, RamWorks style expansion
memory, and ability to drive more modern displays. It doesn't have to
clock at stupidly fast speeds. It should include more than 1mb of
auxiliary RAM (oh how I've longed for one of those 2mb expander
boards).

It should also include all 7 expansion slots, composite output that
does EXACTLY what the standard output does, game connector, cassette
I/O. The RGB output should be capable of driving either old-school NTSC
frequency monitors, or switched to VGA level frequencies. Since it's so
simple to do on the FPGA, it should provide a DVI-I output connector so
either analog VGA or a digital panel can easily be connected, now and
in a few years time when analog output becomes obsolete. The
implementation should conform to the AppleColor standard for RGB,
meaning I have access to colour text mode, plus double hires mono,
colour, and mixed. Since some older software manages to stuff this up,
an override switch to force mono or force colour would be sensible
(would let me reuse the now defunct character set switch)

I figure the auxiliary slot can be ditched, since the board supports
all the functionality this slot was used for. Users of the Microsoft
Premium CP/M card will have to find an alternative solution ;-)

> The problem will be that each quite different design is the product of
> a "quite different" designer, and the probability of any of the detailed
> designs of other "quite different" designers being acceptable to the
> first is almost negligible.

I think though, that the 'quite different' aspects are wholly contained
with the FPGA logic. The general goal is FPGA based design that can be
used like a real Apple II. Some want it to be the fasted Apple II
implementation possible, and that's fine, they can have that within the
general principle. Some want to have cycle accurate implementation so
they can use every peripheral card out there. I want that too -
although I'm prepared to forgo an AUX slot in favour of a bigger than
ever manufactured RamWorks + modern display support.

> If someone put a "plastic" platform with a very modular design out there
> for others to modify, that could create the environment you describe, so
> maybe someone thinks that *that* would be a great project.  (Sounds a
> little like the C-one, doesn't it?  And look how much follow-on work
> that fine project has generated... )

It does sound a little C-one like, and I've even considered using one
of those, but it has the limitation of not having an Apple-II bus, and
I'd like something that mimics the Apple IIe motherboard form factor.
I've always been disappointed by the lack of community development the
C-one inspired.

I know I've got a little 'dreamy' in some of these posts, and if I've
offended your sense of pragmatism, I do apologise ;-) Just pointing out
that if one goes as far as to build an FPGA based Apple II board, there
are many, many possibilities for clever extensions that can be achieved
with only some synthesis and a reprogram.