[Coco] Preserving old CoCo diskettes...

Roger Taylor operator at coco3.com
Tue May 18 17:22:56 EDT 2010


At 03:49 PM 5/18/2010, you wrote:
>On Tuesday 18 May 2010, Roger Taylor wrote:
> >At 02:04 PM 5/18/2010, you wrote:
> >>Roger, why not contribute that code to the nitros9 project?
> >
> >I didn't write an rz/sz protocol that could work at 115200 or 230400
> >bps.  My point was that if you can't get those old programs to work,
> >move on to a new idea using the least number of chip signals as
> >possible.  Hence, a software solution.
>
>rzsz is a separate problem, which is why I mentioned other protocols as being
>faster, much faster.
>
>Since I compiled the rzsz you are, or have played with, I can't argue that
>its architecturally wrong, it is, and that means you are limited to a hair
>over 700 cps on a 6309 machine, and the middle 500's on a 6809 machine.
>It is, in the face of poor line quality, absolutely bulletproof though.  It
>just keeps on hammering until the checksums do match.  The problem is that it
>builds the checksum one &^% char at a time, so that whole loop has to execute
>for every incoming byte.  Grrr.

Exactly.  Always build from a stable program to a faster program, 
with stability coming first.




> >I've found it a much better experience to just mount remote .dsk
> >images and have the files sitting right there in native DOS or OS-9
> >format already good to run or copy.
>
>That sounds like a better idea, but I'm not sure I know how.

But then I admit it could take the fun out of watching rz/sz do it's 
thing, or actually writing the protocol and proving you're still the 
mean coder you used to be.  ;)


-- 
~ Roger Taylor




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