Re: Pictures from the Netherlands

To: linux-connectix@crynwr.com
Subject: Re: Pictures from the Netherlands
From: Jani Mattsson <jmattsso@niksula.hut.fi>
Date: Tue, 9 Jan 1996 00:13:30 +0200 (EET)
From niksula.hut.fi!jmattsso Mon Jan 8 17: 23:26 1996
In-Reply-To: <199601082144.AA05922@ixs.nl>

> BTW, it's night here, so the picture isn't too sharp/clear.

	This hasn't actually to do with the linux-development for the Quickcam,
	but I understood that the CCD cameras are sensitive also in the infrared
	wavelengths, so I was wondering, would it be possible to 'see in the 
	dark' by having a source of invisible IR-light around? At least 
	when pointing a remote control to the quickcam you can see the 
	IR-led flash...

	About Thomas Davis's bi-directional quickcam code, I couldn't quite
	get what is actually being done when reading data from the cam:

        word1 = inw(port);

        while ((word1 & 0x01) != 0x01) {
                word1 = inw(port);
        }

        word1 = ((word1 & 0xff00) >> 3) | (word1 & 0x00ff);
        word1 = word1 << 1;
        word1 = ((word1 & 0x00ff) >> 2) | (word1 & 0xff00);

	So for example in case we have the quickcam in port 0x378, we first
	read a byte from port 0x378 to the low-order byte of word1 and after
	that, a byte from port 0x379 to the high-order byte of word1, right?

	Then we handshake with the lowest-order bit from the data register
	input.. is it really so or did I get something wrong? Would be more
	logical if we still used bit 3 of the status register for handshaking
	as in the uni-directional mode, but...? And this code supposedly only
	works in either 4bpp or 6bpp mode?

// Jani Mattsson <jpm@iki.fi>

Follow-Ups:

Re: Pictures from the Netherlands

From: Thomas Davis <Thomas.Davis@mnscorp.com>

References:

Pictures from the Netherlands

From: Paul Rensel <paul@ixs.nl>