Screen width 1024 doesn't work

[adrazar]

I'm having trouble setting up screens of width 1024, although the manual says this should be possible. Setting the width or height parameter of a screen open instruction to 1024 results in an illegal screen parameter error; anything less than 1024 works though, but the screen size shrinks accordingly. I need all 1024 pixels however, a trick to get it work would make my day

[adrazar]

I might add that I'm using AMOS Pro v2.0 on WinUAE.

Does anyone else get the same error message if writing, say

Screen Open 0,1024,200,8,Lowres
?

[Galahad/FLT]

Originally Posted by adrazar

I might add that I'm using AMOS Pro v2.0 on WinUAE.

Does anyone else get the same error message if writing, say

Screen Open 0,1024,200,8,Lowres
?

Are you trying to display a lowres screen with a visible width of 1024?

Surely you would be using hires?

[Samurai_Crow]

Actually it is a superbitmap scroller, I would imagine.

@adrazar

How much Chip RAM does your system have?

[adrazar]

The chip ram is set to 2 MB. I tried adjusting it up to 8 MB, but it didn't do any difference.

[Samurai_Crow]

The screen should be about 200k so that's not the problem. This may be a long-standing problem with AmosPro.

If you want to scroll one pixel at a time, there's another bug that prevented the horizontal scroll offset from using a value of 15 so every 16th pixel of scrolling will be wrong. There should be a bug-fix in a post at UltimateAmiga.co.uk but I don't know if that would fix the other problem with the maximum width.

[roondar]

I did think it might be connected to Blitter limitations in OCS, but then you'd only get screens up to 1008 pixels wide so that's probably not it (unless AMOS Pro automatically rounds down screen sizes to the nearest 16 pixels horizontally - which is very possible).

Originally Posted by Amiga Hardware Reference Manual

As a practical matter, the blitter size registers also limit the size of
playfields (unless the 680x0 CPU is used for drawing operations). With
the original chip set the largest area the blitter can draw in is 1008 by
1024.

Hope you find a fix though!

[Retro1234]

Whats the largest screen size Blitz can open ECS?

Originally Posted by Samurai_Crow

The screen should be about 200k so that's not the problem. This may be a long-standing problem with AmosPro.

If you want to scroll one pixel at a time, there's another bug that prevented the horizontal scroll offset from using a value of 15 so every 16th pixel of scrolling will be wrong. There should be a bug-fix in a post at UltimateAmiga.co.uk but I don't know if that would fix the other problem with the maximum width.

Ive never noticed this could you explain more and give a link to the patch on UltimateAmiga ?

[Anakirob]

Originally Posted by Retro1234

Whats the largest screen size Blitz can open ECS?

The concept of "screens" does not really translate from AMOS to Blitz. Therefore the meaning of your question is a bit unclear.

Do you mean "what is the largest Bitmap object that can be initialised?"

Well I'm pretty sure that Acid software didn't impose any arbitrary limitations on bitmap size, so therefore bitmap size would be limited only by the amount of free chip memory in the system, and the number of bitplanes of the bitmap in question.

Or do you mean "What is the highest-resolution screen mode?"

Well if you're using AMIGA mode then you should have no problems opening a super hi-res laced screen with full graphics overscan, albeit with an extremely limited colour palette.

But if you're using BLITZ mode then while it's technically possible to access any features the Amiga's chipset has to offer, including Super hi-res and interlaced modes these features may not have any easy way to access or enable them.

[adrazar]

Originally Posted by Samurai_Crow

If you want to scroll one pixel at a time, there's another bug that prevented the horizontal scroll offset from using a value of 15 so every 16th pixel of scrolling will be wrong. There should be a bug-fix in a post at UltimateAmiga.co.uk but I don't know if that would fix the other problem with the maximum width.

I made the screen scroll one pixel to the right every time I clicked the mouse, and as Retro1234 said there were no hickups. It's equally consistent scrolling left.

Originally Posted by roondar

I did think it might be connected to Blitter limitations in OCS, but then you'd only get screens up to 1008 pixels wide so that's probably not it (unless AMOS Pro automatically rounds down screen sizes to the nearest 16 pixels horizontally - which is very possible).

My experiments before posting on this forum revealed that amos indeed rounds screen width down to the nearest multiple of 16.

Your reference to the hardware manual about the blitter is a bit of bad news for me, as I was planning to make a couple of huge bobs stretching across the entire screen...

While this could serve to explain why a screen width of 1024 is impossible, it's still a bit puzzling why it won't accept 1024 in the heigth parameter either.

[Samurai_Crow]

The only features of ECS that are supported in AmosPro is Chip RAM more than 512k. Full ECS support is planned for AmosPro 3.

[Retro1234]

Screen open is just something like iirc Bitmap 0,320,200,4 in Blitz its all pretty much the same.

But as we can see from roondar's post OCS is limited to 1008,1024...

Try 1023 for height

[Anakirob]

Originally Posted by Retro1234

Screen open is just something like iirc Bitmap 0,320,200,4 in Blitz its all pretty much the same.

Are you sure about that mate!? In Blitz mode you will need to initialize a bitmap object first and then use either a slice or a display to use your bitmap. That does not sound like what you're describing. The command for initialising a bitmap by itself will do nothing in the way of opening a display in Blitz, you have to do that manually. And likewise slice and display are kind of useless without a bitmap object.

In Blitz "Screen" refers to an AmigaDOS screen, and if that is what you're talking about then it is possible to turn the screen into a bitmap object so you can draw to it.

Screen 0,0,0,320,200,2,0," 1000 RANDOM PLOTSM ,2 
ScreensBitMap 0,0 
BitMapOutput 0

In this case I would imagine that the largest possible screen on ECS would be Super High-Res Laced max overscan. But even then this is two more steps than what you're describing.

[Samurai_Crow]

Keep in mind that the bitmap image can be bigger than the display on an Amiga if you want to scroll around it.

[adrazar]

Originally Posted by Retro1234

Try 1023 for height

The heights appears to be rounded down to nearest multiple of 8 although the Screen Height instruction returns whatever number was given to Screen Open (unless between 1009 and 1023, these will be reduced to 1008). Anyway, the height restriction is not an issue for my application.

It seems I might have to think up another way of doing things after all then. Thanks for your assistance! Please do post if anyone finds a getaround though.

[volvo_0ne]

1023 works here tho (maybe start from zero) dunno why tho?

1023+0= 1024

however that doesn't seem to be the case for other resolutions.... or is it?

[darkhog]

Originally Posted by Samurai_Crow

The only features of ECS that are supported in AmosPro is Chip RAM more than 512k. Full ECS support is planned for AmosPro 3.

Is? Correct me if I wrong, but isn't europress now defunct and Francois too busy working on Clickteam Fusion 3 to care about AMOS? Not like the sources were ever released and binary patches can ever go so far.

[Samurai_Crow]

AmosPro is open source now. Also, François works on Friend Up now he left ClickTeam.

[darkhog]

He did? I see.