Re: Arrrrrrrgggg!

[Chris Albertson <chrisalbertson90278@yahoo.com>]

Tom Droege wrote:
> 

> Meanwhile, I will hope that the memory cards that are now working will keep
> working until we can get a new system in place.
> 
> The PCI card would have a limited FIFO and some control program that would
> write what it receives directly to memory.  Bill has already done a similar
> project at 1000 times the bandwidth we need so it should be possible.
> 
> Software writers might consider how such a card affects their designs.

Tom,

Please _don't build_ a new card.  There are plenty of standard interfaces
that meet your needs.  You just need to pick one that can handle your pixel
rate at 16 bits per pixel. 

I'd pick an older standard that has been around for years. I think the best
thing to use is bit synchronous serial over a differential cable.
For example RS-422 or RS-530.  Data rates can go up to 10Mbps with very
long cables.  Also there is software to drive these cards for most OSes.
I have even seen RS-422 PC cards that fit in notebook computers.  (Using
a notebook to control a Mark IV camera would be great.) 

On the Mark IV you'd need to add a high speed synchronous chip. 
You could look at using the 16850 UART which has a 128 byte FIFO
built in.  There are also PCI cards with 16850 chips in them.
These will do 1.5 Mbps.

Zilog makes some nicer parts like the Z16C32 which will do
up to 20Mbps and take care of CRC codes in the hardware.
http://www.zilog.com/products/partdetails.asp?id=Z16C32

Here is a serial PCI that uses this Zilog chip.  
http://www.ieci.com.au/products/comm/pci_route56.shtml
I thhink this is exactly what is needed but 16850 based
products will cost less.  For example
http://www.avlab.com.tw/product/p001.htm

There are also multi-port rs-422 cards with 2, 4 or more
serial ports per card.  This would allow one PC to control
multiple Mark IV cameras

THe other way to go would be to put a small computer between the 
Mark IV and the PC.  By small I mean a PC104 sized or even one
built on a SIMM form factor.  This small computer would have both
a fast parallel port and some standard link such as Ethernet.
The control PC would then see Ethernet.

As for the effect of any of this on the PC's control software
I don't see a problem.  If the software runs on Linux or Windows,
either way the I/O is done by operating system level device drivers
which "hide" the hardware from the control software.

--
   Chris Albertson             
   chrisalbertson90278@yahoo.com
   Redondo Beach, California
   home: 310-376-1029
   cell: 310-990-7550