[Coco] COCO FPGA

[Joel Ewy]

On 12/24/2011 02:17 PM, Mark McDougall wrote:
> On 24/12/2011 7:33 PM, Aaron Wolfe wrote:
>> On Sat, Dec 24, 2011 at 3:17 AM, Mark 
>> McDougall<msmcdoug at iinet.net.au>  wrote:
>>
>> On the CoCo3FPGA, DriveWire *does* work with software that accesses
>> the hardware directly, because the CoCo doesn't know it's using
>> DriveWire.  The stock DECB rom is running and talking to what it
>> believes is a stock FDC.
>
> Oh, I stand corrected then. I'm getting confused then, maybe with the 
> DW ROM in Coco3FPGA? I know there's some incompatability there, 
> somewhere?!?
>

If you're using a DW ROM on a 'real' CoCo then programs that hit the 
hardware will miss the DriveWire.  But Gary implemented the DriveWire 
protocol in Verilog (Or is it VHDL?  I know that the CPU09 is in one and 
the rest of the system is in the other, but don't remember which is 
which) on CoCo3FPGA, and it emulates the FDC registers.

JCE

>> Funny enough, any storage option that did use the SD card would
>> probably not be so compatible, just as any of the hard drive/flash
>> storage options available to a real coco are not so compatible.
>
> The idea behind SD is to hang it off the back end of a WD17XX 
> emulation, so it would be 100% compatible. Otherwise, yes, IDE isn't 
> exactly stock either, but given the long-ago availability of those 
> options (like SuperIDE) I personally consider it 'real'. Feel free to 
> differ in opinion though.
>
> Regards,
>