[Linux-decnet-user] Re: DAP , was Hello

[David M. <da...@mi...>]

On 4/2/2004 08:24 AM +0100, Patrick Caulfield wrote:
>On Thu, Apr 01, 2004 at 01:39:28PM -0500, David Mitton wrote:
> >
> > Hello there,
> >       I've just joined this list, and I don't know how much time I have to
> >       spend on the subject.  But I'd like to offer some help if 
> possible and a
> > few comments.
> >
> > - I see that you've rescued a set of DECnet specs from Matt Thomas.  They
> > are no longer visible on the HP website.
> >
> > I have a copy of DAP 7.3.1 dated 21-April-1995 (in text and .RNO) that I'd
> > be willing to contribute.  You only seem to have V5.6 (which is mostly 
> good
> > enough)
> > I was the DAP Architect for a number of years until Aug 1995
>
>I'd love to see a later DAP specification. There are bugs and missing features
>and some small incompatibilities in FAL that might be cleared up by that...

Yes, we tried to fix a number of problems post 5.6. Versions 6.0 and v7.0 
were major upgrades in the protocol.  However, many of changes were not 
implemented mostly due to interia and backwards compatibility.  VMS would 
have done the most work, as it was the most active in adding new 
features.   Though the PATHWORKS (and Ultrix) development did expose issues.

The latest spec would at least provide insight into the correct approach to 
problems or encodings not mentioned in v5.6.

Where do you want the files?

...
>
> > - I was also the designer/implementor of DECnet-DOS and it's
> > kernel.  Though the neurons are a bit rusty, I used to do a DECnet socket
> > programming tutorial at DECUS.  I don't know how well your sockets match
> > ours, but I may be able to dig up some old material.
>
>Actually, one of the DAP incompatibilities is with DECnet/DOS :-)

Nahh!  Not possible. ;^)
One of the best NFT implementations out there.
Seriously, if it's not a bug, maybe it's a mis-understood or undocumented 
feature.  DEC filesystems can be interesting creatures.

Another "feature" of DECnet-DOS was that we wrote a DOS block device (disk) 
driver (NVD) that did a DAP open to a FAL of a file for random access in 
Block mode or Fixed:512 and created a DOS virtual disk using DAP 
protocol.   Only drawback is that DOS block operations are not optimised at 
this level.  Performance could suck big time for disks with large directories.

But it worked for simple xfers if you didn't have an SMB server installed.

Dave.