Re: Apple2 USB Stick interface with Vinculum chip

["RedskullDC" <RDC@oz.org>]

Hi Jorge and Glenn,

"Glenn Jones" <glenn.jones@a2central.com.remove-tkb-this> wrote in message 
46310F91.6529.usenet_csa2@a2central.com">news:46310F91.6529.usenet_csa2@a2central.com...
> bieling wrote:
>> I would do this:
>>
>> 1.- Use FAT -of course- in the pendrive, because a FAT-formatted
>> pendrive can be used too in almost any other computer/OS in the world.
>
> It would also allows direct use from emulators which would be nice.

With an 8K eprom/flash for the firmware on the card there will be plenty of
room to implement both modes.

Virtual harddisk files under the FAT filesystem will probably be easier to 
implement,
so I'll do that one first.

>
>>
>> 2.- Put just the minimum bootstrapping code in the cN/c8 Apple II ROM,
>> just enough to access, load and execute a certain (name predefined, a2
>> code) file to be found in the root level of the FAT filesystem. That's
>> conceptually similar to what the Disk II does.
>>
>> This file can be a driver, a utility, a DOS loader or a menu driven
>> image selector. This way the bootcode, driver, and utilities can be
>> upgraded/updated or even completely rethinked easily later on and
>> won't require any further hardware modifications.
>
> I think a combination of your suggestion and regular $C800 support for a 
> ROM resident block driver (of some description ;-) would be the best bet.. 
> Kind of what Alex Freed did for the Pseudo Disk but with added $C800 
> support because your going to need the space :)

The CPLD will be able to provide all of the select signals, the $CFFF SR 
latch,
plus a few other things.
It could also select from several lots of firmware with an internal 
softswitch.


>
>>
>> If the thing is well documented, this will allow others to contribute
>> on the software side of things, long after the hardware is finished,
>> and the hardware can be completely finished long before the software
>> even gets to beta.
>>
>> I didn't even know about this Vinculum chip. Nice find, and great
>> idea. Seems to fit very well for this project. Good Luck !

Bought mine here in Oz from http://www.dontronics-shop.com/ but they appear
to be available online or in EUR/USA.

By the way Jorge, I like your idea for a Apple2 VGA card.
Have you done any more work on it lately?

Leslie