Re: 1) CD-ROMs

[Rodrigo Caballero Augi <rca@xxxxxxxxxxxxx>]

On Fri, 5 Sep 1997, Steve Hankin wrote:

> Hi Rodrigo,
> 
> 1) Regarding the difficulties that you reported reading of CD-ROM files on
> Linux: We have seen a similar problem reading CD-ROM files on DEC Unix
> machines. In that case we tracked it as far as to determine that there was a
> bug in DEC FORTRAN -- the FORTRAN OPEN statement didn't recognize the CD-ROM
> file.
> 
> If you can work around the problem by mounting the CD-ROM in RW mode (whatever
> that implies on a read-only device??), that sounds like an easy fix, no?
> 
> 2) Regarding the labels on polar stereographic plots: The next version of
> Ferret (already running in our shop) has a vastly simplified approach to map
> projections that will handle labling correctly. Meantime, Mark Verschell's
> suggestion of customizing the polar plotting script is the best route to take.
> 
> 	Happy Ferreting - steve

Dear Steve,

1) I can't mount the cd-rom as RW, because the following
happens:

~# mount -o rw /dev/scd0 /mnt/cdrom
mount: block device /dev/scd0 is write-protected, mounting read-only
 
so the system forcefully mounts it as RO.  What I can do (as a test) is to
mount the _floppy disk_ drive (ie. /dev/fd0) first as RW and then as RO.
Ferret can only access files on the floppy when it is mounted as RW - it
can't see the files when the floppy is mounted as RO. So it seems there is
some Linux-specific problem that does not allow Ferret to access devices
mounted as RO. 

The FORTRAN I'm using (which is GNU's g77) has no problems in accessing
files on the cd-rom. But what actually happens when Ferret meets a "file" 
or "use" command?  Does it trigger a FORTRAN "OPEN" statement? Because if
Ferret is written in Fortran, then maybe compiling it with g77 could solve
the problem ...

As Mark Verschell suggested, I've also tried making a local link pointing
to a file on the cd-rom, but it didn't work.

2) As for the labels, I'm working on a customisation - I'll let you know
how it goes.

Thank you and Mark Verschell for your suggestions.

Regards,
Rodrigo


---

 Rodrigo Caballero Augi |Geophysics Department    |phone: +45 35 32 05 64
		        |NBIfAFG		  |fax:       35 36 53 57
 		        |University of Copenhagen |home:      31 23 05 80
		        |Juliane Maries Vej 30    |e-mail:  rca@gfy.ku.dk
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