Atari ST Display Basics

All information relating to connecting your ST to a modern TV/monitor.
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Re: Atari ST Display Basics

Post by Bikerbob » Sun Nov 26, 2017 3:44 am

So when using the monitor output to the SC1224 it could be pal or ntsc does not matter correct?

What controls the saturation of colour on the ST. IF I have one that puts good colour to the monitor, but another computer same monitor, and the colour is not so good.. red is high, not as bright.. (only changed the computer, no settings on monitor)

Any help on that?

Thanks :)


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Re: Atari ST Display Basics

Post by exxos » Sun Nov 26, 2017 11:44 am

The shifter in the ST is driven from the 5v from the PSU. Also the caps around the RF box causes issues, its why I sell recap kits for PSU & video.
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Re: Atari ST Display Basics

Post by Bikerbob » Tue Nov 28, 2017 4:06 pm

Ok, i was planning on getting a PSU kit from you, I will ask you about the video when the time comes.


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Re: Atari ST Display Basics

Post by Petari » Sat Dec 30, 2017 8:41 pm

This discussion about lack of modulator - actually, lack of color encoder circuit reminded me about what I seen in my time of servicing old computers, around 1983-95 . Secam was in use in practically whole Eastern block, so in Hungary too. Not in Yugoslavia (PAL) . But I did some TV upgrades in that time - added Secam decoders in some TVs on demand.
Commodore 64 was interesting, because it had no extra PAL or NTSC encoder, it was built in it's video chip. Once one C-64 from France arrived. It had RGB output (actually solved with in TV-s used PAL decoder), unlike no other C-64 , Right because same reason why French Atari STs had no PAL encoder. So, that C-64 was usable only with TV or monitor with RGB input if user had Secam TV.
When Berlin Wall fell , Eastern block gradually turned to PAL system. What lasted not long - now we enjoy digital TV broadcasting and much cheaper and much better TVs than in those years. And of course. monitors too.
What is missing here is mentioning that Atari ST(E) have no real/proper PAL or NTSC interlaced video signal, but progressive one in fact. So, not 25 fps interlaced (PAL), but 50 fps progressive, with half of vertical resthan line count on TV is, in fact . That makes sync. problems on some TVs, monitors, TV cards.

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