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

[Bill Degnan]

I 100% promise you'll have better luck with a real black and white tv
from the late 70's early 80's than a modern tv with a cable jack.
There are TV technical reasons for this that I don't remember with the
sync.  Go to a farmer's market and get the correct display. You'll be
much happier.   Some newer TV's don't work.

Then get the manual.

The K is "ok now what?" in Sinclair language.  The user's guide will
tell you what's next. They're online, but if you want a free one, I
will give you one if you come to Kennett Classic to pick it up.  I
have at least one here.

b

On Mon, May 23, 2022 at 7:24 PM Dave McGuire via vcf-midatlantic
<vcf-midatlantic at lists.vcfed.org> wrote:
>
>
>    Yes, but this is NTSC-modulated VHF RF.  Can current TVs receive
> that?  I was under the impression that they don't.  (I don't have one,
> no free time to waste)
>
>             -Dave
>
> On 5/23/22 19:06, Dean Notarnicola via vcf-midatlantic wrote:
> > 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> 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> 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> 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> 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
> >>>>
> >>
>
>
> --
> Dave McGuire, AK4HZ
> New Kensington, PA