The multi-monitor demo coding environment resurrected

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troed
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The multi-monitor demo coding environment resurrected

Postby troed » Sun Mar 02, 2014 4:07 pm

Most coders I knew did not have color monitors - they were too expensive. 14" TV sets were however everywhere, but the picture quality wasn't sharp enough for serious months of all nighter demo coding.

The setup I and others I remember from the Swedish demo scene used was a mono monitor for coding and a TV set for displaying. In the European world of FM-machines this was accomplished with the mono monitor (of course) connected to the monitor output, and the TV set to the antenna socket. It had the very attractive side effect of automatic switching between the screens depending on the video mode - you just had to start your demo (which replaced the VBL vector and thus the default reset on mode-switch) and the picture immediately switched to the TV when low res was set - and back to the SM124 when hi res was reapplied on exit.

Today, it's getting harder and harder to find TV sets with antenna inputs (and, it seems more machines than just mine have started to suffer from drifting or missing carrier on the RF output anyway) - but it's easy to get high res working (most VGA capable monitors can display hi res and an ST->mono VGA cable is cheap) and in Europe I'd assume ST -> RGB scart is the default option for low and medium res.

The point of this post is that I just got, almost, my old coding environment back* :P I have the ST->VGA cable, and the ST->RGB SCART cable. I also have both a 19" flat screen that accepts the ST hi resolution as well as an LCD TV for low/medium res. I could switch which cable is connected to the ST after I've started my code manually, but at the bottom of a box yesterday I found a monitor switch with a manual dip switch to select between them.

After having forgotten to make sure I was in the demo code (with the VBL rout replaced) a few times and seeing my machine reset upon me I looked for something I never had to figure out 25 years ago due to using the antenna output instead - whether it's possible to stop the ST from resetting when switching monitor altogether.

Of course there is :P And now I'm happy. Just make sure $46e points to an RTS instead of the TOS reset routine and you can switch whenever you want to ...

Most people probably knew this. For those of you who didn't, I've attached the smallest util I've ever written (the active part of the code is 2 bytes ;)) since I wrote it for my own usage anyway.

Update: It might be due to the specifics of my monitor switch, but I just realised that I don't even need to flick the dip switch after having turned off the $46e vector. Just as in the good old days as soon as I start my demo screen (which switches to lo res) the picture is output to the TV through the RGB SCART, and when I exit the screen (switching back to mono) the signal goes to the VGA monitor instead. I'm not only happy but VERY happy 8O

/Troed

*) Yes, I could code on my Mac in Hatari or with a cross compiler and move** code on an SD card between it and the HxC floppy emu - but it takes time. Maybe the CosmoSex with mapped network drives will make it quick enough though.

**) Yes, move to target hw. There's no emulator that understands my code ;)
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bullis1
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Re: The multi-monitor demo coding environment resurrected

Postby bullis1 » Wed Apr 02, 2014 5:00 pm

This is very useful and quite cool. Thanks troed :D

I used to use a monitor switchbox to flick between mono and colour on two displays but it reset the machine, leading me to mess with reset-proof RAMdisks. All in all, not entirely useful.

I achieved something pretty effective on my TT years ago when using a videocard. Code on high-res VGA monitor, graphics on standard colour Atari monitor.
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attle
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Re: The multi-monitor demo coding environment resurrected

Postby attle » Tue Jun 10, 2014 5:15 pm

Great tip, excuse my n00b question but where can you get such a switchbox? Are there any places you can buy them or DIY schematics floating around the interwebs? :cheers:

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troed
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Re: The multi-monitor demo coding environment resurrected

Postby troed » Sun Jul 20, 2014 10:18 pm

attle wrote:Great tip, excuse my n00b question but where can you get such a switchbox? Are there any places you can buy them or DIY schematics floating around the interwebs? :cheers:


Mine's factory made from back in the day - but the info here should at least be the same: http://info-coach.fr/atari/hardware/int ... ors_Switch

(Actually I need to open mine up and replace some parts - the RGB signals have gotten desynced, shifted, over the years)

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Re: The multi-monitor demo coding environment resurrected

Postby Dio » Mon Jul 21, 2014 5:00 pm

troed wrote:14" TV sets were however everywhere, but the picture quality wasn't sharp enough for serious months of all nighter demo coding.

Naaaah, it was easily put up with :) .

I coded the whole of Starball on a very, very cheap 14" portable. Even when I had a Falcon that portable TV was still my only output device. I had to borrow a VGA monitor from a mate's PC for testing.

Didn't even realise how easy it would have been to plug it in through the composite port either...


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