[Coco] Another speed question

[Phill Harvey-Smith]

Quoting "Becker, Gary" <Gary.Becker at amd.com>:

>
> I am using a UART compatible with the 6850, not the bit bang port. The
> 6850 has interrupt generation capabilities, but I have never tested my
> implementation. My driver does not enable the interrupt capability and I
> intentionally disable CPU interrupts.

Another way tou could do this, if you didn't mind using a bit of extra  
hardware, would be to use something like the FTDI245, which does  
USB->Virtual com port at the PC (or Mac) end and appears like an LS245  
at the coco end. This chip has an internal transmit and recieve queue,  
so you could run with inturrupts enabled, and still achive a  
reasonable speed.

In the tests that I did with a patched DragonDos rom and a Nitros  
drive, together with a self written drivewire compatible server, I was  
able to get perhaps 10x the speed of floppies, I cirtainly remember  
thinking that's bloody fast :)

I would imageine with a CoCo3 at 1.7MHz or your FPGA CoCo then you'd  
be able to go faster still.

Cheers.

Phill.


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