Re: A little more information

[Tom Droege <tdroege@veriomail.com>]

Chris and all,

Chris, you are the prime candidate to test this.  You have a complete set 
up that is a "source of parallel data".  All we have to do is to make of 
the jumper cable that I have described in the reply to Shawn Dvorak.  I 
have the parts to make such a jumper cable if you do not.

OK, the simple solution may not work.  But we should try it.  If this 
fails, then I can make up a little more complicated kludge board that does 
the right hand shaking.   But I repeat, the PC has to be able to accept the 
data at the rate the Mark IV sends it.  There is no practical way to change 
the scan rate of the CCD and I would not change it if it were possible.

The way to make a low noise system is to always clock it exactly the same 
way.  Once there are pauses (caused by interrupts and the like) in the scan 
rate, this will be reflected as analog offsets that will be different for 
each image.  This is noise that a dark field does not remove.  So there is 
a strong reason for the way I designed the Mark IV with the buffer 
memory.  I do not want to change that design.

Tom Droege


At 02:41 AM 8/15/01 -0700, you wrote:
>Tom Droege wrote:
> >
> > The reason I did not want to try this before is that it requires system
> > level code.  I think we should consider it now.
>
>I don't think it does require "system level code"  unless you define
>all not BASIC code to be that. I'm pretty sure I can copy data from
>a parallel port to a disk file by just typing in one command at the
>command line prompt.
>
>I am thinking somthing like this would read in a 16MB block and store
>it to a file:
>
>         dd if=/dev/lp0 of=myimage.raw bs=16M
>
>I think "dd" has been ported to DOS.  To test I'd need a source of
>parallel data.  Maybe I could use two computers but "dd" should
>work.
>
>--
>    Chris Albertson
>    chrisalbertson90278@yahoo.com
>    Redondo Beach, California
>    home: 310-376-1029
>    cell: 310-990-7550