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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: A1200Dude on August 11, 2019, 05:17:32 PM
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Help please!
I currently have a mostly-stock A1200 (accelerator card, no flicker fixer) hooked up to a NEC AccuSync LCD 71V monitor via the Commodore 23-pin to 15pin adapter...great display for retro systems, displays standard 15KHz Amiga modes in addition to 31KHz and several in between. Love it, but wanted to add a CRT alongside for gaming and a more "authentic" graphics experience.
I found a guy on Facebook marketplace that sold me an Amiga 1080 CRT in good condition and it is currently in transit. What I'm looking for now is a set-it-and-forget-it way to get both displays connected to the A1200 at the same time, without having to swap cables at the 23-pin Amiga RGB port all the time. A dual-monitor, duplicate-display setup, if you will.
I found both a VGA splitter and a 15-pin VGA to 9-pin RGB cable on Amazon that at initial glance looked like they would do the job...connect the splitter to the existing 23-to-15 adapter, plug the VGA monitor into one split, and the 15-to-9 cable into the other split to then send to the 1080. But after talking it through with another user on Facebook, he pointed out that it wouldn't work because the CSYNC line from the Amiga would not pass through to the CRT from any of the splitters and cables in the chain.
I guess what I'm looking for is...are there existing solutions that I am overlooking? Or is this purely a create-your-own-custom-cables thing? If the latter, are there any users here that create cables/splitters that can help with this, or can point me in the right direction? I have zero DIY skills when it comes to cabling so any help getting both monitors connected and displaying simultaneously would be TREMENDOUSLY appreciated!
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If you plan to use the 1080 only for gaming you might want to check wether composite is good enough for you.
Back in the days I had a 2024 on RGB and a 1084S on composite as a similar setup.
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Sheesh, I hadn’t even thought about using composite but that would definitely be the simplest solution. ::) Is the quality decent enough for games compared to RGB or is there a considerable and noticeable drop off?
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Composite isn't really that bad at all. Try it, you might like it. When I first had my A1200, I used RF for quite a while... before I realised my tv had a Composite Video input on the back. I survived with RF so I'm sure you'll survive with Composite. :)
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Ok, I'll just go the composite route then. Now my next question(s)...will the composite output of the 1200 automatically "turn off" when a non-15KHz mode is displayed (e.g. my Workbench screen is Productivity mode)? Or will the 1080 show a scrambled screen?
Also, is there a way to have all 15HKz modes display solely on the 1080 and all the non-15KHz modes display solely via RGB/VGA? Would really like as seamless a "dual display" setup as possible.
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Ok, I'll just go the composite route then. Now my next question(s)...will the composite output of the 1200 automatically "turn off" when a non-15KHz mode is displayed (e.g. my Workbench screen is Productivity mode)? Or will the 1080 show a scrambled screen?
Also, is there a way to have all 15HKz modes display solely on the 1080 and all the non-15KHz modes display solely via RGB/VGA? Would really like as seamless a "dual display" setup as possible.
The composite output won't turn off and it will display a scrambled screen on a 15KHz monitor. What you could do is either turn the monitor off when this happens (it definitely won't do it any good keep turning it on and off), or unplug the composite output from the back of the Amiga every time, or, install a switch somewhere on the cable that turns the signal on/off. Some monitors may have a video channel selection switch so that could be pressed instead. The thing is, I wouldn't want both monitors on all of the time as it's wasting power anyway so I don't quite understand what your after. Also, those 15KHz CRT's have that whistle noise which would be very annoying if on and not being used.
The simple obvious solution is to just hook up the CRT to another Amiga so you can then pick which one you want to use. Alternatively, hook them up to the same machine and edit your Startup-sequence so that holding down the left mouse button boots into a games launcher in a 15KHz mode (TinyLauncher for example), and holding down the right mouse button boots into Workbench in a 15Khz mode (for your graphics applications). If you boot without holding any mouse buttons down then you get your normal 31KHz Workbench for your NEC LCD screen. This saves all the fiddling about, and it's what I'd do.
What you don't want to do is to accidentally display these non 15KHz modes on a 15KHz monitor because it's not supposed to be particularly good for them. :) So, in your 15KHz Workbench boot option (RMB) you'll want to make sure you only have the PAL/NTSC/Euro36 driver in Devs/Monitors. Of course, taking this further there will be some of your software configured for the higher resolution 31KHz modes and these save their settings somewhere (usually ENVARC:) so you could have an alternative ENV with these 15KHz settings for when you boot with the RMB pressed down (I'm talking besides the obvious screenmode.prefs which would have to be switched).
Or, you could have different boot partition for 15KHz. There is a little shell program that can change the boot partition priorities, so this could be used with the mouse detection at the beginning of the Startup-sequence and cause a reboot into the 15KHz Workbench. Of course it will remember it, so you'd have in your sequence either something that reverts it back to your preferred boot (31KHz) or detect the buttons again at the beginning. For example, you might forget which mode you left it on....well, it doesn't matter really, just boot up and hold down both mouse buttons together and it'll boot into 31KHz. You can even detect a joystick press, or a key combination instead. It's all on Aminet, and your options are endless in what you can achieve.
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Ok, so the 1080 arrived and I hooked it up to the 1200 via composite. However, after some fiddling with the front controls of the monitor, I'm only able to display in B&W. Any ideas what could be wrong? (and yes, I've fiddled with the color knob)
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Ok, so the 1080 arrived and I hooked it up to the 1200 via composite. However, after some fiddling with the front controls of the monitor, I'm only able to display in B&W. Any ideas what could be wrong? (and yes, I've fiddled with the color knob)
Is your A1200 PAL and you are in the USA? The composite and RF from the A1200 will be PAL and the two colour systems are incompatible. If the 1080 has a RGB style input on the back then I suppose you'll have to use a VGA type monitor switch or something. Or, adding an Indivision will give you another RGB output, but it seems overkill doesn't it.
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Yes, the 1200 is a PAL unit, but I thought the 1080 was capable of displaying both NTSC and PAL modes. If it were an NTSC television that I was connecting, I could understand that explanation, but not sure I understand why that would matter with a monitor that can otherwise show the mode.
I do have an RGB cable coming in the mail, so I'll be curious to see if that will display the color properly. But if it does, then I'm back to square one with this thread, and needing a way to switch between the monitors without having to constantly swap out the cable (and wearing down the connector on the 1200).
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IMO..
Best solution! find a monitor that responses to both 15 and 31 modes. (multi-sync)
I use a Dell SR2320lf that does this and do not plug/unplug. there are others..
The other solution You already have is a dual monitor, but better is rgb and indivision vga setup.
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Yes, the 1200 is a PAL unit, but I thought the 1080 was capable of displaying both NTSC and PAL modes. If it were an NTSC television that I was connecting, I could understand that explanation, but not sure I understand why that would matter with a monitor that can otherwise show the mode.
It can display 50Hz and 60Hz, but to support both PAL and NTSC would require more circuitry so I suppose they only manufacture these monitors for one or the other to cut costs. Of course, these monitors (Amiga compatible 15KHz types) were used for video work too and it's highly unlikely a user would require both PAL and NTSC as their video equipment would either be PAL or NTSC. I might be talking rubbish for all I know but that's my educated guess.
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I have indivision and it seems to overide the rgb port so you get no signal out of it.
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I too have an Indivision ECS, and can see both screens, because my Dell monitor is picking up the 15 mode.
I just helped another use setup a 4000 with a RTG card and we discovered in a dual monitor system, it's software (cybergraphics)
turned off the rgb when the VGA was running
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I have indivision and it seems to overide the rgb port so you get no signal out of it.
Does it mention this in the manual? I wasn't aware. So the IndiAGA version cuts off the RGB port but the IndiECS doesn't?
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I have indivision and it seems to overide the rgb port so you get no signal out of it.
hmmmm,
I don't have this problem. I get both a DVI output from indivisionAGA and from 23 pin 15 khz port at the same time on my A4000, but I usually am using regular NTSC modes.
Maybe the problem is that you are using a indivision only resolution?
if you use an exotic indivison only mode, it may not show up on the 23 pin port, or at least something you monitor may not be able to display.
I suggest trying a NTSC (or PAL) mode, something like 640x400 and test it.
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Could be a difference between the Indivision 1200 Mk.I and Mk.II regarding the disablement of the video port? Someone must know a definitive answer here. I was under the impression the video output port wasn't affected.
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Ok so it seems like the issue is indeed having a PAL Amiga connected via composite to an NTSC monitor, which as a result will only display the image in black and white. Before I completely give up on this and go the RGB route and swap cables constantly, would something like this work to bridge the PAL/NTSC issue:
THE CIMPLE CO - NTSC to PAL Converter Kit - TV Converter from PAL to NTSC - Bi-Directional TV System Converter Adapter with Two RCA Cables - (White) - Does NOT Convert Actual DVD OR VHS, ONLY Output https://www.amazon.com/dp/B07RHQKHWD/ref=cm_sw_r_cp_tai_GMHxDb3E6MZVF
Could this indeed convert the PAL composite signal coming out of the Amiga and turn it into a full-color NTSC composite signal that the Commodore 1080 monitor could properly display?
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Ok so it seems like the issue is indeed having a PAL Amiga connected via composite to an NTSC monitor, which as a result will only display the image in black and white. Before I completely give up on this and go the RGB route and swap cables constantly, would something like this work to bridge the PAL/NTSC issue:
THE CIMPLE CO - NTSC to PAL Converter Kit - TV Converter from PAL to NTSC - Bi-Directional TV System Converter Adapter with Two RCA Cables - (White) - Does NOT Convert Actual DVD OR VHS, ONLY Output https://www.amazon.com/dp/B07RHQKHWD/ref=cm_sw_r_cp_tai_GMHxDb3E6MZVF
Could this indeed convert the PAL composite signal coming out of the Amiga and turn it into a full-color NTSC composite signal that the Commodore 1080 monitor could properly display?
Interesting, All my RGB (1084) monitors (two P and one D variants) can display 60 Hz NTSC and 50 Hz Pal without any issues, most of the, Monitors of this generation can handle both 50 Hz and 60 Hz signals. The image may need to be resized if one display Pal on NTSC or visa versa.
(as Pal is longer vertically). However this is not an issues with colors. The NTSC and PAL color gamut are almost the same.
The video issue that typically occurs with PAL on an NTSC television (or visa versa) where the TV can only handle one frequency, is image rolling. IE the image rolls vertically as the image does not properly sync or the image does not sync at all and you would not see anything then.
If you have a Amiga OS 2.0 or greater change the Amiga into NTSC mode in early startup menu.
Another thing is that you can jumper the A1200 and make it default into NTSC mode.
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Oh, I just though of another thing that might be happening, on the 1084s there is a switch that changes the monitor from composite to Y/C mode for the monitor's RCA input.
Maybe your monitor. is set to Y/C mode rather than composite mode. If the composite signal is put into the Y (luminescence) all you would see is black and white.
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There is a switch on the front of the 1080 for "comp." and "sep." and inputs on the back for "video" and "chroma." I've tried every combination amongst those four, and still no color composite signal shows, only B&W when on the "video" input ("chroma" displays nothing).
I'm intrigued by what you said here: "Another thing is that you can jumper the A1200 and make it default into NTSC mode."
Is this easy to do? Will this then display an NTSC color signal out of the composite port, or merely make the unit think it's NTSC but video would be unchanged?
If I can't get the composite to work properly, I am back at square one in terms of needing to split the RGB port. Can't believe this is proving to be as hard/rare as it is.
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I'm almost certain you can't make a PAL amiga into an NTSC amiga or vice versa without replacing the RF-Composite circuitry. They are different systems, besides having slightly different clocks and the 50/60Hz issue (or non issue, because as mentioned, monitors will display 50/60Hz anyway).
As for the dual screen with the Indivision, I really thought that Amigakit would have given us a hand here as they have been dealing with them for years and years. Hello AmigaKit? Are you there? ;D
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I'm almost certain you can't make a PAL amiga into an NTSC amiga or vice versa without replacing the RF-Composite circuitry. They are different systems, besides having slightly different clocks and the 50/60Hz issue (or non issue, because as mentioned, monitors will display 50/60Hz anyway).
It looks like you are correct paul1981
According to
http://www.wonkity.com/~wblock/a1200/a1200.html
"Q. Is there an internal jumper on the A1200 to set it to default to PAL or NTSC video?
A. No, but if you're really motivated, you can rig this up. My thanks to Tetsuo Oda and Byron Montgomerie, who provided the information that connecting pin 41 of the Alice custom chip to ground causes the A1200 to default to NTSC, while pulling this pin high (disconnecting it from the motherboard and connecting it to +5V through a 4.7k resistor) will make the default power-up state PAL. I would point out that making a modification like this on a surface-mount chip is difficult at best, and you may end up needing an expensive motherboard replacement, or, at worst, a dead A1200 that needs an expensive replacement motherboard available. In most cases, using the boot menu (obtained by pressing both mouse buttons on power-up or reset) to switch to PAL is sufficient. However, with some games, the hardware patch will be necessary to insure proper timing (changing to PAL via the boot menu might make a 50 Hz game run at 60 Hz timing, or vice versa). "
Sorry, for the miss info, the A2000, A3000, A4000 all have regular NTSC/PAL jumpers
The A500 has a easy to install jumper wire in the later models, but it looks like the A1200 is not so easy
The A1200 is the only common amiga I don't have.
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There is a switch on the front of the 1080 for "comp." and "sep." and inputs on the back for "video" and "chroma." I've tried every combination amongst those four, and still no color composite signal shows, only B&W when on the "video" input ("chroma" displays nothing).
I'm intrigued by what you said here: "Another thing is that you can jumper the A1200 and make it default into NTSC mode."
Is this easy to do? Will this then display an NTSC color signal out of the composite port, or merely make the unit think it's NTSC but video would be unchanged?
If I can't get the composite to work properly, I am back at square one in terms of needing to split the RGB port. Can't believe this is proving to be as hard/rare as it is.
I would expect the 1080 set to "comp." the composite RCA signal to "video" would be the correct combo. (note: I do not have a 1080 so I would get this verified by someone who does.)
I suggest checking the capacitors in your A1200 To make sure none of them are blown.
If anyone is interested A500 and A2000 the "composite" output is grayscale. Back in the day If you wanted full color composite from the A500 or the A2000 you needed an A520 (the NTSC and PAL A520 are different units and not compatible) or some type of genlock.
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Back in the day If you wanted full color composite from the A500 or the A2000 you needed an A520 (the NTSC and PAL A520 are different units and not compatible) or some type of genlock.
Exactly, the PAL/NTSC circuitry is still different when built into the motherboards too. ;)
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I've had a couple of other thoughts that might be potential solutions...
A DB25 switch box like this to use with the Amiga RGB port (that way, each monitor gets its proper full RGB output):
https://www.amazon.com/CablesOnline-Parallel-Printer-Rotary-SB-001/dp/B00E6SQL46/ref=sr_1_8?keywords=db25+switch+box&qid=1566750732&s=gateway&sr=8-8
...assuming that the 23-pin cables for both displays would still fit in the DB25 connector, albeit without locking into place, and that all the proper wiring would passthrough correctly.
OR...a VGA-to-composite adapter:
https://www.amazon.com/dp/B002PXFJ2O/?coliid=I19T8GABAQG631&colid=2TGZ79CDNNMPT&psc=1&ref_=lv_ov_lig_dp_it
...which would come off of a VGA splitter connected to the 23-pin to 15-pin VGA adapter, and then go into the composite on the 1080.
I did order the 15-pin VGA to 9-pin RGB cable I referenced originally, figured if it doesn't work I'll just sent it back. But I'm thinking that the switch box idea would definitely be ideal, as both monitors would be hooked up via RGB then. Has anyone ever used a switch box like that to drive two Amiga displays? Or would this not be doable due to the Amiga's sensitivity to hot-swapping?
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What about a pal genlock with a passthrough?
Genlock's, at least on this side of the pond, are fairly cheap, particularly since the advent of DTV standards.
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Has anyone ever used a switch box like that to drive two Amiga displays? Or would this not be doable due to the Amiga's sensitivity to hot-swapping?
No, never used one. Isn't hot swapping only a problem if you're a clumsy git and short out signals to the edge of the connector? ;D
The one you linked too looks cheap enough, and if it doesn't work couldn't you send it back anyway for a refund?
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Revisiting this...
So I think I will likely go the DB25 switch box route, but would something like this also do the trick?...
https://www.amazon.com/DB25-Female-Male-Cable/dp/B0743YH9TZ/ (This would be preferable as both monitors could then display simultaneously as needed, vs. one or the other with the switch box.)
With either method, I plan on slicing off two pins and part of the DB25 connectors so that the DB23 Amiga connectors fit. Does it matter which two pins (left or right side) get the axe?
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In the mid-'90s I had three monitors hooked up to my A1200. Two on the desk (through 23-pin port and VGA scan doubler 15-pin port) and one at the foot of the bed (through composite output). Two monitors on a desk was pretty unheard of at the time. My friends would ask me why I had two monitors... I'd say "Because I have two eyes, of course!" LOL. :D
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Revisiting this...
So I think I will likely go the DB25 switch box route, but would something like this also do the trick?...
https://www.amazon.com/DB25-Female-Male-Cable/dp/B0743YH9TZ/ (This would be preferable as both monitors could then display simultaneously as needed, vs. one or the other with the switch box.)
With either method, I plan on slicing off two pins and part of the DB25 connectors so that the DB23 Amiga connectors fit. Does it matter which two pins (left or right side) get the axe?
No, but you'd have to cut the same side off of all three plugs of course. I'm not sure what happens about loading the video output with two monitors, whether there'd be degradation.
EDIT: Before you do any cuts, might be best to check with an ohm meter!