Sunday, 10 December 2017

Acer LCD screen that supports Amiga native 15khz modes

Today I wanted to show an interesting LCD screen from Acer that is a current model, available brand new in 2017.


What is so special about it you ask?

Well, it supports Amiga video modes that run at 15khz! So with a RGB to VGA converter you can get native Amiga display on a modern LCD screen, without the need for a scan doubler! Exciting right?

The model I got is a V226HQL model, with the exact information taken from the screen for your reference if you want to get one yourself. Even though I bought this new in it's original box, it is a few years old. I have seen others on Facebook using ones made in early 2017 that work also:


Of course, the Amiga uses a non-standard 23 pin RGB connector, intended for connection to Commodore CRT 1084(S) / 1940 or 1960 monitors. These take up a lot of room and the non-flat displays are very small in this day and age.

To connect the Acer screen to the Amiga, I needed a RGB to VGA converter. This is not a scandoubler - it just converts the existing 15khz signal from RGB to VGA.

These are easy enough to come by on Ebay, but check carefully to get ones that have a REAL 23pin connector, rather than a DIY hacked 25 pin connector on them. Generally sellers try to hide the fact they hack the connectors to make them fit a standard Amiga RGB connection since 23pin connectors are not exactly easy to come by these days. Check the photos carefully and read the seller feedback.

I found a seller on Ebay who makes these converters (from Canada actually), using the right 23 pin RGB connector. I ordered 3 of them!

Here is the converter I received last week:


As you can see it looks well made and the connectors are perfect - here is the RGB connector side:


And here is the VGA connector side:


Since I happened to have the Amiga 1200 out at the time, I decided to try it on that system first. Technically I don't need it since I have an Indivision AGA installed in it already, but hey, why not check it anyway! Here it is connected to the A1200:


On power on I held down both mouse buttons to get the early boot screen, which appeared on the Acer screen straight away! I then brought up the screen mode info screen to confirm it is indeed running at 15khz!!



The screen does promote the screen to this slightly odd 1440x288 screen mode, but it looks fine and the aspect seems ok too. I tried modifying the usual fill screen/aspect control to adjust it to 4:3, but it doesn't change the screen. So the resolution is what it is, but as I said, it displays fine from what I could see.


I moved the screen to a better place since it seemed to be working fine:


I then decided to try a different Amiga. I hooked up the Amiga 600 next. As with the A1200, I already have a Indivision ECS installed in the A600, so technically it doesn't need this screen either.

You can see it installed here, with the MAS player hardware (for MP3 playback) also installed in the back of the A600:


As you can see, the output from the RGB port at 15khz to the Acer screen works fine on the A600 also:


Something to remember though is that because it is native 15khz output that is not scan doubled or flicker fixed, any interlace modes will flicker the screen, the same as all Amigas do on the 1084S monitor or tv output.

Running Bomb's E255 demo on the A600 looked great on the Acer screen:



Next up I hooked up the Amiga 1000, one of the systems I wanted to get this screen for. Unlike the other Amigas I don't have a Indivision ECS installed or a scandoubler connected to it. It needs this screen, and so I was very excited to try it out. As you can see the Kickstart screen came up fine on the Acer:


I did hit some trouble here with the Amiga 1000 though. For some reason when I booted any kickstart disk, the system wouldn't display the Insert Workbench disk screen and instead hung on a black screen. The screen was displaying something, but the system wasn't responsive.

As a test I removed the converter from the RGB port so there was no display. I then booted from the kickstart disk and the machine was clicking the drives so I knew it was at the Workbench boot screen. I connected the RGB to VGA converter at this point and the display appeared and worked perfectly!


Strange behaviour though. It only seems to happen on the Amiga 1000. I tried 1.0, 1.1, 1.2 and 1.3 kickstarts and also all three converters I bought and they all do the same thing. Having plugged in the RGB to VGA converter after the Insert Workbench disk screen appeared, it did work perfectly on the A1000 though - here is Digital Innovation demo running nicely through the Acer on the A1000 at 16khz? Strange huh?


I guess the 16khz is what causes the problems but really don't understand that one. If anyone knows what is happening here please let me know.


Maybe it is just my Amiga 1000 - dunno.


Last, but not least, I connected my CDTV to the Acer screen. It also doesn't have a Indivision ECS scandoubler installed, and until now I use the AV out to connect it to a TV, or my HDMI upscaler to convert the signal to display on my HDMI LCD screens. Now though, I can connect the CDTV directly from the RGB port to this new Acer screen since it can accept the 15khz output. As expected, once powered on it worked great:


I fired up the rather excellent Rink A Pink demo, booting via floppy and it worked great on the Acer too:


Close up photo shows the output is 15khz:



Since I can use it great on the CDTV, I decided to leave it setup for now and played some tunes from the Immortal 4 CD while preparing this blog post.


There is a useful wiki that lists all the 15khz compatible models that people have tried out, which includes the one I covered here today. You can read it here.

It is great that we have options in 2017 to output our ~30 year old Amiga systems to modern screens, still supporting the 15khz output required! If I had more room I would buy more screens now that I know they work, but things are tight in here these days space wise. I might get one more though as a backup...


27 comments:

  1. How would a TFT screen flicker? It has no rays in a cathode tube. Have you tried an actual flicker mode on it?

    ReplyDelete
    Replies
    1. Interlace screens are drawn with the even lines first, and the odd lines second, causing the flicker.

      The signal from the Amiga tells the LCD to light a pixel for ~1/60th a second (~1/50th for PAL) the same as a CRT.

      So just like a CRT the even lines will start to turn off as the odd lines are being drawn, causing the flicker. Now there are all kinds of scalers and things in modern LCDs doing other stuff, but basically that is what happens.

      Just because it is an LCD it does not mean the pixels will persist, in fact quite the opposite.

      If anything the flicker could be worse because the phosphors in a CRT keep emitting after the beam hits them, whereas the LCD pixels do not (literally like shutter doors closing).

      This is all a limitation of a 15Khz analog system.

      Delete
  2. Same thing with my A1000 and NEC 71v monitor, after kickstart is loaded, black screen. Fine on other systems.

    ReplyDelete
    Replies
    1. Interesting. I guess it is an Amiga 1000 thing then. Thanks for sharing this info.

      Delete
  3. Hmmm.... very tempting, as the 1940 attached to my aging A1200 is on its last legs (some burn-in, power button is broken). But, its $200. Still, it would give me a spare monitor.

    ReplyDelete
  4. Sigh... I bought one and it doesn't work with my A1200. It displays "Input not Supported".

    ReplyDelete
    Replies
    1. I am sorry to hear that. There are many similar Acer models so I hope you got the exact model I photographed in this post. I am in Australia so I don’t know if the exact same models are sold overseas. That’s why I included the exact model information. Others have reported it works fine for them so perhaps it is a vga converter issue in your case?

      Delete
    2. Yes, it's the exact model V226HQL, purchased in NZ. Date of manufacture is June 2017. I don't think the VGA converter is a problem, as it works fine with my Commodore 1942.

      Delete
    3. If it is not the converter, then I am not sure what the issue is. There isn't anything else to configure to make it work in my testing. My converter is different to yours as I got it from Ebay (Canada) rather than the one that comes with the C1942. The screen works perfectly with my Amiga 1200 as shown in the pictures, along with all the other Amigas I tested it with here. Perhaps try a different converter and see if that resolves it?

      Delete
    4. Well, I got it working. I was using DoublePAL screenmode. Reset the Screenmode to PAL, connected the Acer, and it booted. The problem is that PAL is a significantly smaller screen than DoublePAL. So.... a monitor that can do 15 khz is good, but what would be even better is a monitor that can go 27.5 khz.

      Delete
  5. Did you open your adapter? Is there a buffer chip for the sync signals in there? The A1000 is probably thinking it has a genlock connected if your adapter is unbuffered.

    ReplyDelete
    Replies
    1. Interesting point. I should check that. Not sure if I can do much though if it is there, other than buying a different converter! Going to be hard to know if it has a buffer chip or not from the photos...

      Delete
  6. Rink A Dink, not pink. :)

    ReplyDelete
  7. you have to be careful on which adapter you buy. I bought one from AmigaKit and it does not work with my Lcd.
    A gentleman on Amibay from CZ sells ton of stuff there and his adapter work great. Name there is A.MI.Goun

    ReplyDelete
  8. Can you give the eBay seller you purchased the adapter from? Thanks

    ReplyDelete
  9. you can also use and old or new LCD panel and buy a LCD controller kit ebay etc and have them program the firmware with 15khz compatibility or buy 1 of the cheap programmers sold in same places and burn your own as this is the only thing in a LCD tv/monitor that stops us from using 15khz

    ReplyDelete
  10. FWIW, this is Rink a Dink, not Pink. (Yes, the logo misleadingly drawn.)

    This is cleared up and many other amazing improvements are made in Rink a Dink Redux: https://www.pouet.net/prod.php?which=61182 the 25 year anniversary remaster.

    (Or if more convenient, you can get the disk image here: https://files.scene.org/view/parties/2013/revision13/oldskool_demo/rink_a_dink-redux_by_lemon-point_fixed_party_version_.adf )

    ReplyDelete
  11. Nice write up! I have one of the adapters from AMibay. Same Seller that David Wright mentioned. It also works on my Monitor which is an ACER K202HQL

    ReplyDelete
  12. Thanks for posting this. What is the clarity compared to a CRT? I have seen that if screen resolution from the computer to the LCD is not in its native mode the screen can be blurry. Also, I want to ask about the moving of the mouse or the Amiga screens if this monitor has a good refresh so that it doesn't look like things are staggering.

    ReplyDelete
  13. Do games also play in full screen or can they be played in 4:3 with this monitor? if they do will they look weird stretched? thanks.

    ReplyDelete
  14. You can also get these if you want a VGA-adaptor (and S-Video).
    http://electronics.chroma.se/svideo.php

    ReplyDelete
  15. I found two models of LCD monitors that support amiga 15kHz and 50Hz refresh for smooth scrolling: 17" benq bl702a and 19" benq bl912. They are almost 4:3 ratio, native 1280x1024. I've tested it with CDTV, A1200 and A4000

    ReplyDelete
  16. I've the same issue on my A1000, while connected after powering up: No Picture at all.
    After disconnect RGB and reconnect the Picture will appear on Screen and bootsequence will go ahead.
    It really seem to be the missing bufferchip inside the adapter.
    Thx for explaning, now i will install a syncbuffer inside the adaptercase and check it out again.
    Greets from Hamburg-Germany
    Achim

    ReplyDelete
  17. I bought the Acer V226HQL today from my local store Computer Alliance in Brisbane Qld and wanted to say thank you, it worked immediately with my Amiga using a vga adapter. I have been looking for so long for a tv or monitor that worked. Thank you for your blog.

    ReplyDelete
    Replies
    1. No worries. I am glad to hear it! Enjoy :-)

      Delete
  18. Would an Acer V226HQL BBD work?

    ReplyDelete
  19. I noticed they make several models the V226HQL um.wv6sa states it has the displayport and the others say hdmi can you confirm port on yours

    ReplyDelete