1024x768 x 24 not possible on Cybervision64 ?!

[Jose]

Hi. Just got it from the post yesterday and set it up using the supplied floppy. It's probaby a very old version of CybergraphX.
1024x768 at 24bit mode simply doesn't exist in the list of screenmodes.
 I'm not gonna mess more with it now cause it's the end of the year but I leave this here for suggestions.

:pint: :pint: :pint:
:pint: :pint: :pint:

[dnelsonfl]

Jose wrote:
1024x768 at 24bit mode simply doesn't exist in the list of screenmodes.

Verify the memory on the Cybervision. Think you might need a 4MB version for that resolution and color depth.

-David

[Piru]

@Jose

You tried adding the mode with CGXMode?

[Jose]

@dnelsonfl
All the sockets are filled. It must be the 2MB version upgraded to 4MB.

@Piru    
The version of Cybergraph I installed (from draconian times) has a program called CyberMode or something.
I tried it today and managed to create a mode that worked, but above 55Mhz the screen get's messed up.

Anyone managed an higher frequency? 55Mhz is to flickey to me.
Maybe I should try CGX 3.x or Picasso ?

[Amigaz]

I don't think it will work read this please:
( I also had that question)

http://www.amiga.org/forums/showthread.php?t=14943


Running 800x600 24bit on my CV64, still haven't got a 1024x768 16bit screenmode up yet which is my goal

[Jose]

@AMIGAZ

Well, I can't try it right now cause I have only one monitor and not enouph space near it for two computers and it's a mess to switch the A4k and the PC all the time, but I can guarantee you that mine gets much more than 55Hz at 1024x768 x16. It actually even gets around 70Hz at the next higher resolution IIRC.

Maybe the monitor also takes part in the equation. Mine is a 19"Nokia 446Pro wich has an absolutely cool image. I had to get into service menu to raise color intensity a bit though.

Anyway, next time I use the A4k I'll take note at the working resolutions and frequencies.

[AntonioX]

Hi I also have tryed to get this screen mode also but I could not and just give up, and iam just using 1024x768x16
I dont think it is possible but if it is I would love to know how its done

[x56h34]

I think that 1024x768 x 24 is only possible with CV64 if "interlace" is turned on.

IIRC, I've had the same problem in the past, when I owned a CV64 card with 4MB of video ram.

[Amigaz]

Jose wrote:
@AMIGAZ

Well, I can't try it right now cause I have only one monitor and not enouph space near it for two computers and it's a mess to switch the A4k and the PC all the time, but I can guarantee you that mine gets much more than 55Hz at 1024x768 x16. It actually even gets around 70Hz at the next higher resolution IIRC.

Maybe the monitor also takes part in the equation. Mine is a 19"Nokia 446Pro wich has an absolutely cool image. I had to get into service menu to raise color intensity a bit though.

Anyway, next time I use the A4k I'll take note at the working resolutions and frequencies.

Cool, would be very grateful if you could post the frequencies for the 16bit 1024x768..I'm using a 17 inch Sony Trinitron monitor which is probably 3-4 years old

[Framiga]

i've always used 1024x768 at 16 bit on my CV64 (4meg) since the beginning. (at 24 bit, it would crawl)

If you haven't it already, chose New from CGXMode

Type=16bit

ScanMode=Normal

and from the list of the preconfigured modes a

1024x768 (70Hz, 56.5Khz) VESA

and Test it. (it should be a safe mode for your monitor)

If its OK, save it.

EDIT- if for some reason when you click on Test, the test screen isn't showed correctly, click on ESC to exit.

[Erol]

Use the picasso software instead, you'll be surprised how much faster it is over cybergraphix.

[TjLaZer]

You need to try Picasso96 it is better and faster than CyberGraphX.  And it is compatible too.  I use it on my CV64 and CV643D works awesome.

[Jose]

Ok I finally done it, here are some of the tested frequencies using a Buster 9 (if it has anything to do with it anyway..).

For some modes I lowered the Sync Lengths the lowest possible to be able to raise the frequency a bit. I don't know if all monitors will accept these. Values presented are the best I could get for these modes but I can't remember if I tryed to lower the sync legnths when the attained frequency was already high. I only present the synch lengths for the 1024x768 and 800x600 modes, both at 24bit.  
Pixel clock also had to be adjusted cause above certain levels image gets messed up.  Pulse offsets didn't make any difference so I kept them under normal values (just clone an existing mode and use it's values)

800x600 24bit:
Scan Mode- Normal
Pixel Clock- 55
Sync Lenghts:
Horizontal- 232(doesn't allow less)
Vertical- 47 (maybe less is possible to raise frequency didn't try)
Frequency- 82,37Hz :-)
NOTE: WHEN THINGS MOVE IN THE SCREEN I GET THOSE ARTIFACTS SOME OF YOU MENTIONED BUT NONMOVING PICTURES ARE PERFECT.
TO TAKE THEM OFF I HAD TO lower the pixel clock to 32 wich resulted in 49,85Hz (You might want to try to lower the vertical sync length)

1024x768 24bit:
Same values but lowered the synch lengths to maximum: 232(doesn't allow less)  and 12 (less would make the picture disappear), for horizontal and verticall ones respectivelly.
Frequency- 56Hz


16bit Modes:
NOTE: I didn't had any of the mentioned artifacts that I got when moving things around the screen with 24bit.

1024x768
Other values as previous mode. Pixel clocks maximum value is 107 otherwise picture gets messed up.
This resulted in 88.54Hz.

@1152x864:
Other values as previous mode:
Frequency- 72,4Hz

1280x1024
..
- 57Hz

1400x1100
-49hz

[patrik]

@Jose:

The reason for this is as I wrote in the earlier thread Amigaz linked to, is that the maximum pixelclock decreases drasticly with increased depth of the resolutions. This simply because the bandwidth between the Trio64 chip and the onboard VRAM is not enough for more. This what is supposed to be max pixelclock for each bit-depth:

8-bit - 130MHz max
16-bit - 80MHz max
24-bit - 50MHz max

I have though experienced that if you use a higher pixelclock than ~48MHz in 24-bit, there will be graphics corruption, especially when stuff is moving on the screen.


/Patrik

[patrik]

@AMIGAZ:

To get a 16-bit screenmode in 1024x768:

Start CGXMode and select a monitor corresponding to the limitations of yours. If you can find your monitor in the list - select that one, else select "Monitor-85kHz" - that one will allow you to drive the CV64 to the limit, which your 17" Trinitron will have no problems handling.

When that is done, create a new screenmode, select 16-bit as type and then select "1024x768 (75Hz, 60kHz) VESA" from the list of predefined screenmodes and press "Ok". Then save, reboot and voila - you have a 1024x768 screenmode in 16-bit.


/Patrik