Experiences with a composite video mod for a Sinclair ZX81
drlegendre at gmail.com
Sat Jan 2 20:22:47 CST 2016
"It's interesting that none of my present TVs would tune properly to the RF
of the ZX81 but they will with some of the other RF only computers like the
Coco 1 and Atari 400? More circuitry in the latter perhaps..."
I'd have no idea about that one, other than I can verify that there was a
lot of variability in the video quality of early game & home computer
My first machine was a (NTSC) VIC-20 which I ran on a 12" B&W RCA TV set
from the late 1970s. It was not all that bad, really - quite legible with
those massive characters, but not so great for games or anything requiring
color recognition. I was very happy to receive a "proper" S-Video monitor
with my C-64, which arrived some two years later.
On Sat, Jan 2, 2016 at 8:06 PM, Terry Stewart <terry.stewart296a at gmail.com>
> On 3/01/2016 2:50 pm, "drlegendre ." <drlegendre at gmail.com> wrote:
> > Thanks Terry, fair enough. =)
> > Has it been done with the ubiquitous 2N2222A? That one is probably in
> > everybody's kit.. it might be even more common than the 3904
> > Wondering.. is there a way to re-purpose that Chan. 3/4 switch as an RF /
> > Composite switch? That way you'd still have a correct (local) RF output,
> > well as the Composite video.
> Actually you probably could if you wanted to keep RF. You'd have to make
> sure it's hardwired to the right RF channel of course but yea..
> It's interesting that none of my present TVs would tune properly to the RF
> of the ZX81 but they will with some of the other RF only computers like the
> Coco 1 and Atari 400? More circuitry in the latter perhaps...
> Terry ( Tez )
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