[Coco] WiFi modem.

[RETRO Innovations]

On 1/20/2018 4:09 AM, Gene Heskett wrote:
> On Saturday 20 January 2018 04:12:37 David Ladd wrote:
>
>> On Sat, Jan 20, 2018 at 2:12 AM, Gene Heskett <gheskett at shentel.net>
> wrote:
>>> On Saturday 20 January 2018 01:30:46 RETRO Innovations wrote:
>>>
>>>
>>> ​<cut>
>>>
>>> So it boils down that I am not in a position to advise, just warn
>>> that all facets need to be checked. With the speed limits of the
>>> coco in handling an error correction protocol such as rzsz, flow
>>> controls are a must when the baud rate goes above 240. Even less if
>>> its multitasking heavily.
>> ​Gene, in this case Jim could more than likely easily make a version
>> of his board using two 6551's for compatibility and set one 6551 to
>> the standard Deluxe RS232 address space and then set the second 6551
>> to the Modem Pak's address space.  I myself would even love one of
>> these. :D (wink wink)
>
>
>
> I have fought with the limited i/o space in the coco's because of tandy's
> decision to use a $20 wide space for a pia that needed 4 bytes, not
> once, but twice! Properly decoded, that wastes 7 usable 4 byte wide i/o
> spaces per each pia.
>
> Thats room for 14 more i/o gismo's without any address clashes with
> existing stuff we all own.
>
> I have even gently begged the layout expert folks like Jim and Ed, even
> Roger, to make us a kit to fix that. But apparently with the number of
> different boards over the years, its not practical
The problem is not practicality, but of combination.  Removing the 
"mirrors" (repeated address ranges are termed "mirrors") only makes 
financial sense to implement when you have something to put in those 
mirrors.  No one wants to buy a "de-mirror" device that offers no new 
functionality.

So, if we can decide what needs to sit in those mirrored locations, the 
CPLD or FPGA can happily remove the mirrors and place the new 
functionality in that space.

Jim

-- 
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