[Coco] RS DOS RS232 application?

Brian Blake random.rodder at gmail.com
Fri Apr 15 07:28:17 EDT 2016


Both CoConet and Drivewire 4 had versions that supported 230k. Not sure
that what you're looking for, tho.
On Apr 15, 2016 1:44 AM, "Gene Heskett" <gheskett at wdtv.com> wrote:

> On Thursday 14 April 2016 22:42:10 Dave Philipsen wrote:
>
> > Have you compared the pshs/u puls/u instructions for moving data
> > quickly?
>
> No I haven't Dave. I did look at the cycle counts a long time ago, and
> ldq/stq were a fewer cycles less on the 6309 as it skipped the 2nd
> instruction fetch on the 6309.  And moved 4 bytes at a time, so I just
> used the 6809 equ that moved 2 bytes at a time if that is what its
> running on. For incoming or outgoing data thru a 6551, if a 4 byte fifo
> in hardware could be built that only its driver knew about, that would
> handily demolish the timeing requirement of clearing the 6551 read
> register before the next byte was clocked in.  Frameing errors would
> melt away till at least 2x the speed on a 6809.
>
> This is also a major roadblock to the use of rzsz at higher speeds
> because the current implementation is a one byte at a time monster.  And
> it cannot deal at all with a data window bigger than 256 bytes.  I
> should have been working on Tim K.'s code, which I think could handle
> the bigger block sizes.  Putting the table lookup cnc method into that
> should have resulted in at least a 2x speed improvement like it did for
> rzsz.  But we have better phone lines today, so its extreme error
> correction ability that results in the speed limit, is IMO wasted.
>
> > Dave
> >
> > On 4/14/2016 7:14 PM, Gene Heskett wrote:
> > > On Thursday 14 April 2016 19:58:35 RETRO Innovations wrote:
> > >> I would like to test out a mod to my RS232 pak to bring it up to
> > >> 230kbps.  Is there a simple app around that has source so I can
> > >> modify it to do 230kbps on my rs232 pak and test?  Or,
> > >> alternatively, is there a simple terminal that I can run to test
> > >> out the various existing bps rates?
> > >>
> > >>
> > >> Jim
> > >
> > > Unless you have huge buffers, big enough to contain the whole
> > > transmission, the coco cannot move more than about 90k a second.
> > > That corresponds to the megaread times I was able to get from myram,
> > > of 11 seconds for a megabyte on a 6309, and just over 13 seconds on
> > > a 6809, each using the fastest way to move data that exists on those
> > > 2 processors. For the 6809, thats (after the transfer is setup)
> > > ldd,x++; std, y++, or for the 6309, ldq ,x++;stq ,y++ (IIRC).
> > >
> > >> --
> > >> RETRO Innovations, Contemporary Gear for Classic Systems
> > >> www.go4retro.com
> > >> store.go4retro.com
> > >
> > > Cheers, Gene Heskett
>
>
> Cheers, Gene Heskett
> --
> "There are four boxes to be used in defense of liberty:
>  soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> Genes Web page <http://geneslinuxbox.net:6309/gene>
>
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