Direct writing on Hard disk

[pogge55]

I need to write on HD a data stream of about 120 Mbytes/sec (coming from a Digital camera), I find that this amount of data can be written on a HD type "Barracuda" but I don't know how to do this, can anyone help me?

Wishes

 

[gabby]

Hi

First how much data you are going to store???
Second i think you have a samll mistake in calculation of the transfer-rate
120Mbytes/second ???? 8O or 120Mbit per second?(write the hd type)
you don't have (i think)any hd that can store 120Mbyte per second... :?
(is a diferrence in the tharnfer rate of the cables and the internal
transfer for store , on the cables they have more high transfers
for give you the power to transfers to some hd in the same time)

So give us some more info???
Interface of hd scsi/ide , hd part no , kind of the pc (if you chose) or non pc-system your video card interface (pci 33m- 66m) etc..


Best regards. 8)

 

[echo47]

I assume your data is continuous, such as digital video.

Look in the Barracuda data sheet at "Average Formatted Transfer Rate", and you will see approximately 35 MB/sec. I don't think any existing drive can sustain 120 MB/sec. You need multiple drives, a good RAID controller, and a computer bus faster than ordinary 32-bit 33 MHz PCI.

 

[rainbow]

Digital Camera

I guess a couple of more questions might be:

What brand of Camera?
Still or Video?

Most Stilll cameras have a removable memory device which can be read on a regular PC with the appropriate adapter...Several Still cameras also have a jack..which when used with the appropriate software and cable..allow the information on the camera to be treated like another Hard Drive on the computer.
With either transfering data is as easy as cut and paste.

I am not positive about Video...but it seems reasonable that they would also have such a port....or at least a video or S-Video port which can be used with a "Dazzle" card to transfer the video to your computer..


Hope this helps a little..
Rainbow

 

[pogge55]

Digital camera

Hi Sirs, I didn't replay to your questions because I was not at work.

I'm sorry beacause I realize that I was too criptic in my post.

The digital camera that I use is a : DALSA 1M-60 that has a CCD sensor
1024x1024 pixels and is capable to output 60 frame per second.
The output is converted (inside the camera) in a word 12 bits wide (this means that on the bus I need two bytes per sample).

As you can see the recording speed that I need is 120 MBytes per sec.
The lenght of the recording is about 20 minutes.

I don't think that this rec. speed can be managed on a normal PC (this i due to the limitation of the OpSys), I tried on a dual Pentium with to coreco frame grabber units but the maximum speed was about 12 frames per second (under win2000). There is one PC solution that I know: (see https://www.conduant.com/) but its very expensive above 10K$.

I know that there are some military HD recording units that replaces the HDDT tapes for the recording of radar images, they use an array (8 units 75 Mbytes each) of seagate barracudas with fiber channel interface and it can reach about 140 MBytes per second. I have no other info on such units.

There is also military application for this camera for aerial reconoissance, that use barracudas and a VME? based computer.

I think that the hardware to perform this task exists.

My idea is to build a simple electrical interface from the LVDS output of the camera and the disk but I don't know how to perform a direct write on the HD.

Best wishes.

 

[BGA]

Check www.t13.org for IDE specs.
I'm trying to do something similar but with the help of DSPs!
Let me know.