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
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@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
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@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@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
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@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@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@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
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@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@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@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@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
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@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@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@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@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
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@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@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@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@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@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
Yes. I have a very recent 4K 70” set and it does ATSC and old school NTSC just fine with a top loader NES with RF only. On Mon, May 23, 2022 at 7:24 PM Dave McGuire via vcf-midatlantic < vcf-midatlantic@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@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@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@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@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
My belief is that the new ATSC compatible TVs have a disadvantage in that they try to auto fine-tune RF signals fed to them. I'm sure they are all capable of displaying the signals from old sources, but the tuning logic, most likely digitizer based direct sampling, will lock onto the strongest signal, even if it potentially overdrives the RF decoder's input. Older TVs generally had analog fine-tuning, even automatic (AFT) style. This probably allowed the ability of the TV to attenuate stronger than normal signals to some degree to get them to display. Just a theory... until it is disproved. :) Jeff Salzman On Mon, May 23, 2022 at 8:04 PM Dean Notarnicola via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
Yes. I have a very recent 4K 70” set and it does ATSC and old school NTSC just fine with a top loader NES with RF only.
On Mon, May 23, 2022 at 7:24 PM Dave McGuire via vcf-midatlantic < vcf-midatlantic@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@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@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@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@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
I agree Besides, Nearly any yard sale or estate sale has a TV for sale. I just picked up a nice little Sony TV with video inputs for $15. Sent from: My extremely complicated, hand held electronic device.
On May 23, 2022, at 7:06 PM, Dean Notarnicola via vcf-midatlantic <vcf-midatlantic@lists.vcfed.org> 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@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@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@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@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
Ah, ok. I stand corrected. Apologies. Tx. From: Dean Notarnicola <dnotarnicola@gmail.com> Sent: Monday, May 23, 2022 7:06 PM To: vcf-midatlantic <vcf-midatlantic@lists.vcfed.org> Cc: Glenn Roberts <glenn.f.roberts@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@lists.vcfed.org <mailto:vcf-midatlantic@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@lists.vcfed.org <mailto:vcf-midatlantic@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@lists.vcfed.org <mailto:vcf-midatlantic@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@lists.vcfed.org <mailto:vcf-midatlantic@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
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@lists.vcfed.org> wrote:
Ah, ok. I stand corrected. Apologies. Tx.
From: Dean Notarnicola <dnotarnicola@gmail.com> Sent: Monday, May 23, 2022 7:06 PM To: vcf-midatlantic <vcf-midatlantic@lists.vcfed.org> Cc: Glenn Roberts <glenn.f.roberts@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@lists.vcfed.org <mailto:vcf-midatlantic@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@lists.vcfed.org <mailto:vcf-midatlantic@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@lists.vcfed.org <mailto:vcf-midatlantic@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@lists.vcfed.org <mailto:vcf-midatlantic@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
Possible fixes for a potential buyer: https://retrorepairsandrefurbs.com/2021/07/05/sinclair-zx81-restoration/#:~:... . On Mon, May 23, 2022 at 9:12 PM Bill Degnan via vcf-midatlantic < vcf-midatlantic@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@lists.vcfed.org> wrote:
Ah, ok. I stand corrected. Apologies. Tx.
From: Dean Notarnicola <dnotarnicola@gmail.com> Sent: Monday, May 23, 2022 7:06 PM To: vcf-midatlantic <vcf-midatlantic@lists.vcfed.org> Cc: Glenn Roberts <glenn.f.roberts@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@lists.vcfed.org <mailto:vcf-midatlantic@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@lists.vcfed.org <mailto:vcf-midatlantic@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@lists.vcfed.org <mailto: vcf-midatlantic@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@lists.vcfed.org <mailto: vcf-midatlantic@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
I am 99% sure that the ZX 81 or the TS 1000 has a standard RF modulator. And yes it does I’ll put a black and white signal Sent from: My extremely complicated, hand held electronic device.
On May 23, 2022, at 9:11 PM, Bill Degnan via vcf-midatlantic <vcf-midatlantic@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@lists.vcfed.org> wrote:
Ah, ok. I stand corrected. Apologies. Tx.
From: Dean Notarnicola <dnotarnicola@gmail.com> Sent: Monday, May 23, 2022 7:06 PM To: vcf-midatlantic <vcf-midatlantic@lists.vcfed.org> Cc: Glenn Roberts <glenn.f.roberts@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@lists.vcfed.org <mailto:vcf-midatlantic@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@lists.vcfed.org <mailto:vcf-midatlantic@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@lists.vcfed.org <mailto:vcf-midatlantic@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@lists.vcfed.org <mailto:vcf-midatlantic@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
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…
I plug Ataris and C64s into my ~3 year old Sony HD flat panel via RF. There is some noise, but I was kind of amazeballs at the fact that it worked. Later tonight when I am not being lazy I will dig out the ZX81 and plug it up and see what it does. I think it's in the TI-99/4A and Atari 800 bin. - Ethan
THe Sinclair is much simpler/more primitive. On Mon, May 23, 2022 at 7:57 PM Ethan O'Toole via vcf-midatlantic <vcf-midatlantic@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…
I plug Ataris and C64s into my ~3 year old Sony HD flat panel via RF. There is some noise, but I was kind of amazeballs at the fact that it worked.
Later tonight when I am not being lazy I will dig out the ZX81 and plug it up and see what it does.
I think it's in the TI-99/4A and Atari 800 bin.
- Ethan
It certainly is, but it's still NTSC over VHF (ch3/ch4) RF. -Dave On 5/23/22 19:58, Bill Degnan via vcf-midatlantic wrote:
THe Sinclair is much simpler/more primitive.
On Mon, May 23, 2022 at 7:57 PM Ethan O'Toole via vcf-midatlantic <vcf-midatlantic@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…
I plug Ataris and C64s into my ~3 year old Sony HD flat panel via RF. There is some noise, but I was kind of amazeballs at the fact that it worked.
Later tonight when I am not being lazy I will dig out the ZX81 and plug it up and see what it does.
I think it's in the TI-99/4A and Atari 800 bin.
- Ethan
-- Dave McGuire, AK4HZ New Kensington, PA
Correct, the tuner demodulates it just dandy. On Mon, May 23, 2022 at 8:23 PM Dave McGuire via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
It certainly is, but it's still NTSC over VHF (ch3/ch4) RF.
-Dave
On 5/23/22 19:58, Bill Degnan via vcf-midatlantic wrote:
THe Sinclair is much simpler/more primitive.
On Mon, May 23, 2022 at 7:57 PM Ethan O'Toole via vcf-midatlantic <vcf-midatlantic@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…
I plug Ataris and C64s into my ~3 year old Sony HD flat panel via RF. There is some noise, but I was kind of amazeballs at the fact that it worked.
Later tonight when I am not being lazy I will dig out the ZX81 and plug it up and see what it does.
I think it's in the TI-99/4A and Atari 800 bin.
- Ethan
-- Dave McGuire, AK4HZ New Kensington, PA
participants (8)
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Bill Degnan -
Bob Shuster -
Dave McGuire -
Dean Notarnicola -
Ethan O'Toole -
Glenn Roberts -
Jeff S -
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