[Coco] WiFi modem.

Gene Heskett gheskett at shentel.net
Sat Jan 20 03:12:15 EST 2018


On Saturday 20 January 2018 01:30:46 RETRO Innovations wrote:

> On 1/19/2018 6:16 PM, Gene Heskett wrote:
>
> It looks like I have not implemented the auto RTS function as yet (the
> HW is set up for it, but I have not written the Verilog). Sockmaster
> used some RC delays and TTL logic to implement his version, but I'd
> like a less timing sensitive option.
>
I don't recall writing the above, Jim.

> I assume it's:
>
> If RXD line goes active, set RTS inactive
> When read of reg 0 occurs, set RTS active
>
> But, thoughts are appreciated.

Its been yonks since I last battled with it. When the serial stuff got 
split into hardware and driver modules, much of the code was thrown out, 
I assume because it wasn't understood, and flow control has not worked 
since. Even xon/xoff is dead because theres no recovery from an xoff in 
todays drivers IIRC. 7wire did work flawlessy circa 1994 or so but has 
never worked against a linux ttl port. Which side was at fault? Don't 
know, and was tired to trying to stay ahead of nitros9's changes so I 
gave up and made drivewire work.

My 6551's are all the 30 yo versions. I wasn't aware there were bugfixed 
versions available till yesterday, and I've not been advised what the 
differences are between the 65C51S and the 65C51N that I can get from 
the likes of Mouser. Obviously for new designs, one should use the 
smaller square version packaging, but does that lend itself to 
piggy-backing like the minidips for a poor man's dual port?  I again do 
not know if tsop legs can be straightened to stack them. It may be that 
with the modern packaging, just lay out a 2nd pattern so that a 2nd chip 
can be added later if a dual port is needed, the only diff is the chip 
selects, one is inverted so they are adjacent 4 byte wide blocks in the 
i/o space. Beyond that, back to the books I guess.  The mouse driver is 
of course functioning so it does not need a device descriptor as its all 
in the latest joydrv.sb, which IIRC I made it so various addresses for 
the hardware can be set with xmode.  Save the driver once thats done, 
and use the saved copy for new boot generation. I think. Its been a 
while since I wrote that, 5 or so years back.

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.

> Jim
>
>
> --
> RETRO Innovations, Contemporary Gear for Classic Systems
> www.go4retro.com
> store.go4retro.com


Cheers, Gene Heskett
The above content, added by Maurice E. Heskett, is Copyright 2018 by 
Maurice E. Heskett.
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Genes Web page <http://geneslinuxbox.net:6309/gene>


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