[Coco] WiFi modem.

[Gene Heskett]

On Saturday 20 January 2018 15:40:30 RETRO Innovations wrote:

> On 1/20/2018 2:35 PM, Gene Heskett wrote:
> >  From the tone of the last message in that thread, it agrees with
> > mine. Sounds like the NXP SC28L92 might be a far better deal. But
> > again I've no clue how much support glue other than cs decoding it
> > might need. If the crosslink is followed, there are pdf's available
> > there for these chips. QFP44. 10mm sq. looks like a good package
> > choice. Theres also some sync logic glue samples in one of those
> > messages.
>
> The main problem is that the 28L92 is not register compatible, so
> you'd be leaving all existing SW out of luck.  As a general rule, I'm
> not a big fan of breaking compatibility.
>
All this time I've been aware of that, but then I've always assumed a new 
driver would present a compatible interface to the user, at least under 
os9. I am obviously not a fan of rsbasic, which IIRC runs on basic, 
quite likely with its own serial port code, so that has colored my 
thinking. A new driver for os9/nitros9 is a relatively minor problem, 
but that won't make ultimaterm run.

So you are correct in that you'll have to make an fpga interface that 
fixes the bug, and is invisible to the likes of ultimaterm. But my 
experience with fpga's is limited to programming them on the interface 
cards used between the computer, and the motors that run my machinery, 
using ready prepared files that I've never had in an editor. In my case 
I have several choices of interface protocols, using 42 megabaud writes 
and 25 megabaud reads, 32 bit packets, over an SPI buss fabricated from 
the gpio pins on the pi's and their ilk. So I can use the same card with 
an EPP parport interface, (but somewhat slower since even the EPP is 
limited to about 5 mhz or as an SPI on the same 26 pin header.  So I can 
program the fpga, but I haven't a clue how to write the program thats 
written.  So you are several legs up on me.  But I'll sure buy the card 
if you make it.

> > I've no clue if NXP is making a 6551 clone thats not broken, but the
> > fifo's in this chip would certainly be an advantage.
>
> I did not find one.
>
> Jim


Cheers, Gene Heskett
The above content, added by Maurice E. Heskett, is Copyright 2018 by 
Maurice E. Heskett.
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