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Re: Are there any 65816 card schematics?

Tristan Mumford wrote:

Sean Fahey wrote:



 To: Tristan Mumford
There are two kinds of 65816 options (generally speaking).

The first type is the slotted variety - which can either work
cooperatively with the rest of the system or it completely takes over the
system when active. These options tend to be software driven and therefore
not very compatible with
other applications except those that are written/patched to support it.
These
kinds of cards are generally intended for cross-platform development,
scientific analysis or some other "high-end" computing task.



I seem to recall hearing about a Z80 card that cooperatively used the
system. It needed complex software. Sort of like the C64 CPM cart. It was
up to the 6510 to handle interrupts still (I think).


Most coprocessors ran cooperatively with the 6502 so that the 6502
could do I/O, particularly Disk ][ I/O.

Many coprocessors used the DMA line to hold off the 6502 to access
main Apple memory (for buffers or graphics), even if they had plenty
of program and data memory "on board".


Are the complete system takeover style cards still a slave to needing custom
patched software while the '816 is running in 6502 compatibility mode?


The one's I know of (like AE) ran 6502 software, but that's up to the
designer...


The other 816 option is the processor replacement - and here we have a
couple of sub-options.... some accelerators for the 8 bit II took an 816
no problem - and while you could execute those extra ops, strange things
may happen, plus you could only address the usual RAM locations.

Then there are the socket boards - like the Applied Engineering 816, which
is a board that mounts over, and replaces the 6502. It has strap cables
that can be hooked up to a RamWorks card and... if I read correctly, a
Ramfactor board... which would give it 2-8MB accessible RAM.

I have one of those AE cards, and it may get cloned eventually.



They sound pretty good.
Memory addressability is the main issue though. Like I said in another post
I could just make a banked memory card, but... well, I just don't want to
do it that way :)


Accessibility of additional memory is one reason for putting the '816
on an Auxiliary Memory card.  That could give the '816 a linear view of
the memory and the 65(C)02 the conventional banked view (though seeing
chunks of the memory as "stack" is probably not very handy ;-).


Apart from when I'm just messing around on it, it'd be running a custom
build of Contiki. There would be a fairly noninteractive (to the local
user) server app. Either the multiplayer 'vaguely roguelike' game I started
writing for this purpose at the beginning of the year, or something else as
yet undecided. 

Actually, there was a very nice integration of a 65816 with an Apple II
compatibility mode--I think it was called the IIgs.  ;-)

Seriously, why not run your large-memory apps on a IIgs and save
a lot of non-standard trouble?

-michael

NadaNet networking for Apple II computers!
Home page:  http://members.aol.com/MJMahon/

"The wastebasket is our most important design
tool--and it's seriously underused."