ard at p850ug1.demon.co.uk
Mon Dec 4 17:54:08 CST 2006
> Tony Duell wrote:
> >> Gordon JC Pearce wrote:
> >>> I still have my (almost) fully-loaded Atom
> >> I was hoping that by 'fully loaded' you meant that it had the BBC BASIC,
> >> Econet and Colour boards :-) (I've never seen a real example of the latter,
> >> although I know that there's at least one in the UK)
> > What does the colour board look like, and where does it fit?
> I can't recall what it looks like now - I've never seen the real board, and
> the only photo I knew of was on the 8bs website (which has been down for many
> many months now, although it will be coming back one day we're promised!)
> However, from memory, the board intercepted the signals to/from the video IC
> socket, and then the Atom's displaced video IC (umm, a 6847 I think) plugged
Oh, right (and yes, the video chip is a 6847)
> into the colour board itself. I think that the 6847 chip was colour-ready
> anyway; it's just that the standard Atom doesn't include the necessary
>From what I rememwebr of the 6847 datasheet, it generates the YUV signals
for _NTSC_ colour. I guess the colour board converted those to PAL.
> circuitry to make use of it (I think the floating point ROM actually contains
> the code to make use of the board). I also have a funny feeling that the
> colour board didn't provide component RGB - it'd only allow colour via the
> modulator and displayed on a TV.
That is not suprising. Getting RGB froma a 6847 is a little more complicated.
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