[Coco] RS DOS RS232 application?

[Gene Heskett]

On Friday 15 April 2016 07:28:17 Brian Blake wrote:

> Both CoConet and Drivewire 4 had versions that supported 230k. Not
> sure that what you're looking for, tho.
>
Apples v oranges. Bitbanger v 6551, and the 6551 needs more housekeeping.

> 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>
> >
> > --
> > Coco mailing list
> > Coco at maltedmedia.com
> > https://pairlist5.pair.net/mailman/listinfo/coco


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>