Image on CRT's in Fast mode?

General Chit Chat about Sinclair Computers and their Clones
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RetroTechie
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Re: Image on CRT's in Fast mode?

Post by RetroTechie »

Thx everyone for your answers! :)

So TV screen simply turns blank - sometimes black, gray(ish) or even white. And with the TV losing sync, prompting some TV's to go for a blue screen or display a message. Fwiw: that actually matches what I'm seeing with -my- composite modded ZX81's: a blank, white screen as if the "K" cursor had been erased.

Seems my memory is failing me... :lol: I do remember the "no signal" snow being kind of hypnotizing at times. Meditative / relaxing in a way, especially if you focussed on a few individual pixels. Sometimes a lot of VHF / UHF searching was needed to set up a TV (also for use with machines like Zeddy or Spectrum). Probably that "no signal" snow image got mixed in with ZX81 memories... :mrgreen:
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PokeMon
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Re: Image on CRT's in Fast mode?

Post by PokeMon »

Yes - I would say if you switch off just the ZX81 connected via RF to your TV, older TVs must have displayed it's snow for missing signal. Unless a chip included detecting missing signal and show a message instead.
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gammaray
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Re: Image on CRT's in Fast mode?

Post by gammaray »

RetroTechie wrote: Thu Apr 20, 2017 2:15 am Thx everyone for your answers! :)
...
Seems my memory is failing me... :lol: I do remember the "no signal" snow being kind of hypnotizing at times. Meditative / relaxing in a way, especially if you focussed on a few individual pixels. .... Probably that "no signal" snow image got mixed in with ZX81 memories... :mrgreen:
When trying to get channel 2 or 3 in the States (this worse channels for reception. hence the ones available for universal use on US Zeddy and gaming systems) there was a mixing of the signal and white noise trying to fine tune into ZX output. Sometimes the screen looked like an ice-rink just before using the Zamboni.
5-TS1000,UK ZX81<-Sheelagh, US ZX81, 2-TS1500/KDLX , 3-TS2040 printer, 2-TS2020 cassette decks, ZXPAND+AY, ZeddyNET, ZXBlast, UDG, ZX8CCB, AERCO, BUILDS/REPAIRS ZX Spectrum, ZX80 Minstrel, ZXMAX48 v1 v2, 2-TS-2068, ROM, 16kRAM
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