Re: DOS 1 & 2

["Michael J. Mahon" <mjmahon@aol.com>]

Paul Schlyter wrote:
> In article <rNKdnSo0wpiBRbbbnZ2dnUVZ_ompnZ2d@comcast.com>,
> Michael J. Mahon <mjmahon@aol.com> wrote:
>
>
> > Bryan Parkoff wrote:
> >
> > >    Steve Woz and his contractor developed DOS 1 and DOS 2 for Apple II. 
> > > DOS 1 and DOS 2 were used for beta testing, but they were never released to 
> > > the public until DOS 3.1 became available.  Correct?  Do you have idea what 
> > > DOS 1 and DOS 2 look like unfinished RWTS routines?
> >
> > AFAIK, DOS 3.1 was the first publicly available version.
> >
> > Since Woz wrote RWTS in the process of developing the Disk ][ drive and
> > controller, it's safe to say that RWTS preceded any DOS version.
> >
> > The very first RWTS may have been 4+4 coding, but Woz quickly progressed
> > to 5+3, then later to 6+2.  The final iteration was the ProDOS-style
> > RWTS that decodes nibbles to data on the fly.
>
>
> Actually, already Apple Pascal did that.  And it dind't just decode
> nibbles on the fly while reading, it also encoded nibbles on the
> fly while writing.  The latter I believe is more difficult to
> implmenent, due to the code writing to disk being so time critical.

I certainly agree, writing is much more demanding.

My reference to "ProDOS-style" was not meant to imply that it
first shipped in ProDOS, but that the most common encounter most
Apple II users will have with this "RWTS" is in ProDOS.

-michael

NadaNet networking for Apple II computers!
Home page:  http://members.aol.com/MJMahon/

"The wastebasket is our most important design
tool--and it's seriously underused."