aiiadict{at}gmail.com wrote:
> On Nov 18, 11:05 am, a2avia...{at}gmail.com wrote:
>> On Nov 18, 7:23 am, a2...{at}hotmail.com wrote:
>>
>>> Don't make a JACPMC - just another CP/M card - make something awesome.
>> Let the Feature-Creep begin!
> 
> ok...  have a port to plug in the Uther ethernet module.
> Z80 drivers for the module, TCP/IP in Z80, ?make? some sort of
> protocol for communication between the Apple's 6502 and the
> z80...
> 
> It would free up RAM for Contiki, and CPU time as well.
> 
> Contiki could say "Z80 in Slot5, I request this data: 123.123.123.123/
> file.ext, put it at $4000 in apple memory"
> 
> Z80 downloads the file and ?DMA?'s it to apple II RAM, and sets a flag
> (SUCCESS) which will have a value of 1 for true, 0 for false (data get
> failed)

Neither the Applicard nor CardZ180 used DMA for transfer between host and 
guest processor.  They both relied on programmatic transfer.  For example, the 
Z80 writes a byte to a port and polls a status bit to see when it can write 
the next one.  6502 checks a status bit on its side and reads the byte from a 
memory address when it's ready.
--- SBBSecho 2.12-Win32