Amiga and BENQ BL912 / BL702A Monitors

[idrougge]

I have read that using csync instead of h/vsync in your cable leads to smoother scrolling, but at the cost of going into the menu and selecting YUV mode each time the monitor is started.

[liquidsmoke]

Originally Posted by idrougge

Do it again, both for text and graphics.

i was forgetting to save the overscan results.
did it again, saved, and now its working fine.

Originally Posted by dodke

If you don't mind resolution switching the one higher frequency mode that seems to work fine on mine is euro72. It's 640x400 and absolutely no vertical line artifacts.

just tried euro72. looks bad. tried loads of pixel clock and phase values, and none of them could get rid of these strange horitzontal bars on the edge of the screen - like the teeth of a comb.
and it did not fill the screen - 1-2inch borders on all sides. overscan would not work with that screenmode.






cannot get dblpal to work right. the resulting image has 1-2inch borders on all edges, and overscan will not go beyond those edges to fill the screen.
plus it seems very slow compared to pal-hires




anyway to get rid of the flicker in pal-hires-laced?

[pedranic]

Hello, i have just bought a BL912. Its great! But i have a problem, it doesn't save the config... i adjust pixel clock and phase and after turn off and turn on again, the config is gone!

[jvidia]

Is it normal for the image in the Amiga 500 with the Benq BL912 to be right indented using one "Amiga VIDEO - VGA (DSUB) Adapter"?

I'm using kickstart 1.2 @ WB 1.3

Adjusting the "H. Position" to the left to center the image, I get on the top right a black zone/stripe.
Adjusting the "V. Position" up to get that black zone to go away I get the black zone on the bottom right this time instead.
Is it normal too?

With a higher resolution, for instance in WB 3.1 using ACA500Plus, the image will center it self?

Thanks!

[deling]

Originally Posted by Nibbler

I got a Benq BL702A today.

First i was shocked by the vertical lines and scaling artefacts but i use the Pixel Clock and the Phase to get rid of it. I used Dpaint with a grey background to do this and now its really nice. No more lines.

The only thing that really annoys me is the Auto Adjust
If i change the resolution or maybe some Whdload gameswitch from pal to NTSC all the settings get lost

Is there a way to deactivate the dawm auto adjust ? .. so annoying

Hi I have same problem with this monitor ! im am very frustrated
did You resolved problem with auto adjusting ? How Can I disable auto adjusting , this is very stupid function , should be off this function

[MartinW]

As far as I know you can't stop the auto-adjust. But it remembers around 5 (guessing) sets of settings so you should be able to get it such that all the resolutions you typically use are remembered and you don't have to keep adjusting them all the time. That's what I've managed anyway...

[franeti]

Hi guys!

I just got a benq bl912. I have bought the rgb-vga adapter in amigastore and it does not show an image on my Amiga 500 or 1200. I also have Cd32 with CD32 Expansion Slot with vga and there it works (without using rgb-vga adapter) so the monitor works. every time I press a button on the monitor it only lets me choose the source and always the same failure, it does not detect anything. any suggestions?

This is the adapter:

https://amigastore.eu/en/207-amiga-r...-modified.html

[jbenam]

Five years later, I have finally got one - a BL912AB.

Great monitor. I have attached it next to my multisync Microvitec M1438 and it's honestly MUCH easier on the eyes and way more detailed. Had to fiddle with Phase, Clock and H/V position until I got it right, but now it looks perfect.

I am just missing a bit the scanlines the M1438 produced, but imho it's not a tragedy. I will keep testing, still have to test interlaced screens

[turrican9]

Originally Posted by jbenam

Five years later, I have finally got one - a BL912AB.

Great monitor. I have attached it next to my multisync Microvitec M1438 and it's honestly MUCH easier on the eyes and way more detailed. Had to fiddle with Phase, Clock and H/V position until I got it right, but now it looks perfect.

I am just missing a bit the scanlines the M1438 produced, but imho it's not a tragedy. I will keep testing, still have to test interlaced screens

Yeah. I tried many CRT TVs using RGB and PC CRT monitors but threw them away. CRT TVs hurts my eyes and even a PC CRT monitor using scandoublers will hurt my eyes due to the 50Hz flicker. A PC CRT monitor needs 85Hz to feel comfortable for me. Not gonna happen with 50Hz PAL Amigas. I even remember back in the days, early 90s I had a 14 inch CRT TV with my Amiga 500. Using RGB scart. Even my then much younger eyes would hurt when trying to read text in workbench or in adventure games.

Time and time again I have tried CRTs and always go back to my BL 702A/BL912s.

I have two BL 702As and one BL 912. If you pair them with scandoublers like AGA MK3 for A1200 or ECS V3 for ECS/OSC machines and make a nice profile for full overscan at 50Hz and vsync (720x576) they will look even better. Nicer and sharper. Not that the 15KHz picture from these monitors are bad. And adding some scanlines looks really nice in games. But you have to get the profiles right. Not only that, but these scandoublers are also flicker fixers. So nice to run a flicker free interlaced hi-res workbench.

[suppah]

Originally Posted by khph_re

Will these monitors support doublePAL? also on the 19 inch version, is there a way to connect my c64 as well?

Yes. They support every Amiga screenmode, they are great in NTSC, great in PAL and also can be used in DBLPal like i do with my A1200s provided you add VGAOnly in devs:monitors as it increases a bit display/refresh frequencies so that BenQ (and other general VGA monitors) can handle them bettter.

They are not CRTs of course but as for LCD monitors i think they are widely the best you can find for Amiga.

[LieboLBX]

Just picked up a 702A.

What’s the highest resolution on a stock A1200 with nothing but a 23-pin to VGA adapter please?

[eXeler0]

Originally Posted by LieboLBX

Just picked up a 702A.

What’s the highest resolution on a stock A1200 with nothing but a 23-pin to VGA adapter please?

with or without interlace?

[LieboLBX]

Originally Posted by eXeler0

with or without interlace?

Either or. Ideally I'd like no flicker on interlaced modes but I remember using something like MagicTV2 from Aminet to reduce flicker slightly in the past.

[eXeler0]

Originally Posted by LieboLBX

Either or. Ideally I'd like no flicker on interlaced modes but I remember using something like MagicTV2 from Aminet to reduce flicker slightly in the past.

The max resolution of the monitor itself is 1280x1024 which is actually 5:4, not 4:3 so in theory its a very good match. I used to have one connected to one of the A1200ds but now I use other monitors for them so the 702 is connected to an A500 where it matters less.
But Any resolution your standard A1200 can do is not higher than the theoretical max of the monitor. But unfortunately I dont remember all the details about how it handles all available Amiga 1200 modes.
The annoying thing I do remember though is that it forgets its settings every time you switch screenmode, so jumping between WB in high res and a game in low res is annoying as it will forget, lets say, horisontal position etc…

[LieboLBX]

Not having issues with the position, just the flickering in interlaced mode. I’ve reverted back to using SCART on an LCD TV where there’s litter to no flickering.

[MartinW]

You shouldn't get issues with it forgetting settings unless you switch between a lot of different modes all the time by maybe hooking it up to a bunch of different systems. The internal memory has room for a certain number of settings. I don't know how many. Once that room is full it will replace the oldest one with the latest one you save. That's how mine appears to work anyway, it's not like the exact specifics are in the manual.

So if you've been merrily trying out tonnes of modes on your 1200 to find one that works well then yeah, it's probably going to seem like it doesn't remember them. Work out which mode you want to use for RTG, then factory reset it, then dial in just the modes you want (RTG, PAL, NTSC?). It should have plenty enough memory to remember those few modes.

[EDIT] PS: Sorry, I don't remember what mode is the highest you can get out of a stock A1200. I have a PiStorm32 connected up to mine so I only use the BenQ for PAL these days and the only other Amiga I used it with was again RTG.

[LieboLBX]

Thanks for your input.

[macce2]

I just bought a Benq912 monitor (Thanks, Pekka !) .
My first impression is positive, and the picture quality with
my Indivision mk2 card is good.
However, I was unable to succesfully install the Picasso96
software; I even tried several versions of the software.
I do have a working PicassoIV card installed.
The install procedure seems to work ok,
However, when I'm trying to load up my system;
there appears a message telling something like:
"Could not create context for the PicassoIV (?!)
; check your P96 installation."

I think the selections I made while installing are all ok;
mostly default; but the first question:
"Which horisontal frequencies can your monitor handle ?"
I was unable (!) to find the correct max value for Benq912
from anywhere, it seems to be missing even from the
user's manual, which is weird.
The vertical max frequency is given, 76 Hz (!?).
Because I didn't know the exact max value for
the horisontal frequency; I just tried 31 Khz to be safe.
Could this problem be the actual cause for my
non-working installation of P96 software..?!?
Could anyone help me, please!

Ps. The picture quality through PicassoIV (boot menu etc)
was not so good and a disappoitment; there are
horrible vertical bars )


UPDATE: The theoretical maximum horizontal scan rate can be
calculated by multiplying the maximum amount of horizontal
pixels (1280) with the maximum (vertical) refresh rate (76 Hz)...!?!?
If so, the answer has to be about 97 kHz ?!
Could someone confirm this ?

[jbilander]

Originally Posted by macce2

UPDATE: The theoretical maximum horizontal scan rate can be
calculated by multiplying the maximum amount of horizontal
pixels (1280) with the maximum (vertical) refresh rate (76 Hz)...!?!?
If so, the answer has to be about 97 kHz ?!
Could someone confirm this ?

Hi, a 1280 x 1024 resolution at a refresh rate of 76 Hz requires a horizontal scanning rate at around 80 kHz.





You can confirm that by looking at the VESA standard for 1280x1024 at 75 Hz:

http://tinyvga.com/vga-timing/1280x1024@75Hz

Note you also have other refresh rates at 1280 x 1024 in the standard.
1280 x 1024 @ 60 Hz timing
1280 x 1024 @ 85 Hz timing
1280 x 1024 @ 100 Hz timing

but the last two of those would be off limits for the Benq BL912 I think if 76 Hz is the absolute max refresh rate.

In analog TV systems the horizontal frequency is between 15.625 kHz and 15.750 kHz. In Amiga land a TV compatible resolution would for example be HiRes:

640x200 @ 60 Hz (NTSC)
640x256 @ 50 Hz (PAL)

The Benq monitor can handle such a 15 kHz signal too, it will scale to fill the 1280 x 1024 native display resolution.

[zipper]

Spec for 912: Horizontal Refresh Rate 83 kHz