[vcf-midatlantic] ZX81/TS1000 with a modern TV

[Dean Notarnicola]

Possible fixes for a potential buyer:
https://retrorepairsandrefurbs.com/2021/07/05/sinclair-zx81-restoration/#:~:text=The%20Sinclair%20ZX81%E2%80%99s%20only%20video%20output%20is%20modulated,the%20degradation%20caused%20by%20modulation%20and%20subsequent%20demodulation
.


On Mon, May 23, 2022 at 9:12 PM Bill Degnan via vcf-midatlantic <
vcf-midatlantic at lists.vcfed.org> wrote:

> Just to reiterate, get an original analog black and white TV.  The
> Timex Sinclair TS100/ZX81 is not compatible with modern TVs.   These
> computers do not generate a broadcast TV synch signal so even
> kinda-old TVs will have issues with the Sinclair.  There is someone
> who made an adapter for the ZX 81 in England, but then you have poss.
> PAL/NTSC issues to deal with.
>
> This was a topic of discussion a few times over the years in these
> here vintage computer lists....you can search for these online.
>
> Bill
>
> On Mon, May 23, 2022 at 8:39 PM Glenn Roberts via vcf-midatlantic
> <vcf-midatlantic at lists.vcfed.org> wrote:
> >
> > Ah, ok. I stand corrected. Apologies. Tx.
> >
> >
> >
> >
> >
> > From: Dean Notarnicola <dnotarnicola at gmail.com>
> > Sent: Monday, May 23, 2022 7:06 PM
> > To: vcf-midatlantic <vcf-midatlantic at lists.vcfed.org>
> > Cc: Glenn Roberts <glenn.f.roberts at gmail.com>
> > Subject: Re: [vcf-midatlantic] ZX81/TS1000 with a modern TV
> >
> >
> >
> > I’ve yet to find a TV that can’t do ATSC and NTSC.
> >
> >
> >
> > On Mon, May 23, 2022 at 6:26 PM Glenn Roberts via vcf-midatlantic <
> vcf-midatlantic at lists.vcfed.org <mailto:vcf-midatlantic at lists.vcfed.org>
> > wrote:
> >
> > I have no experience with Sinclair but didn’t they have a built-in RF
> modulator? That would put out an old style UHF or VHF signal that a modern
> digital TV can’t decode. I believe you’d need an older TV to test these…
> >
> > Sent from my iPad
> >
> > > On May 23, 2022, at 5:54 PM, Dean Notarnicola via vcf-midatlantic <
> vcf-midatlantic at lists.vcfed.org <mailto:vcf-midatlantic at lists.vcfed.org>
> > wrote:
> > >
> > > I’ve read that the ULA on some older TS and ZX units do not put out a
> 100%
> > > proper NTSC signal, something do with the contrast. It may be that
> modern
> > > TVs have issues, but CRT tuners can deal with it. Considering they are
> all
> > > demonstrating the same behavior, these units may be fine.
> > >
> > >
> > >> On Mon, May 23, 2022 at 4:32 PM Jeff S via vcf-midatlantic <
> > >> vcf-midatlantic at lists.vcfed.org <mailto:
> vcf-midatlantic at lists.vcfed.org> > wrote:
> > >>
> > >> The K cursor is normal, and standard. The ZX81 does not have any kind
> of
> > >> intro or status boot screen. If you're seeing the K, then unless
> there's
> > >> something wrong with the keyboard, you should be able to see any
> numbers
> > >> you type.
> > >>
> > >> On Mon, May 23, 2022, 4:21 PM Bob Shuster via vcf-midatlantic <
> > >> vcf-midatlantic at lists.vcfed.org <mailto:
> vcf-midatlantic at lists.vcfed.org> > wrote:
> > >>
> > >>> So I have two (2) Sinclair ZX81s (US version - one is still an
> unbuilt
> > >>> kit), and three (3) Timex-Sinclair 1000s.  I’ve connected them to a
> TV
> > >>> using an RCA-coax adapter and tuned to the correct channel, but I
> get a
> > >>> grey screen with the “K” cursor visible.  I’m unable to get past
> this.
> > >>> This is for all four units.  They seem to tune in white momentarily
> then
> > >>> switch to fuzzy grey - with the “K” still visible.  This was both on
> a
> > >>> large 4K OLED set and a small HD LED TV, and I suspect they are just
> too
> > >>> new to deal with the monochrome signal.  I don’t have a CRT TV to
> test
> > >>> with, just old monitors (which of course don’t have antenna
> connections.)
> > >>>
> > >>> Any advice?  I’m selling these, so I’m not getting into modding them,
> > >> just
> > >>> want to confirm they’re working properly.
> > >>>
> > >>> Bob Shuster
> > >>
> >
>