Amiga VGA Output Should it Fill The Screen?

[emiliom]

I just finished building a MiSTer Multisystem about a week ago and now I'm trying to understand how the MiSTer system works and how to get everything running correctly.

With the Amiga core, when I run the core and Workbench screen comes up it completely fills the screen. When I 'insert' a game disc, the output shrinks down. I would say it's 3/4 the height of the whole screen (maybe a little bigger), with narrowish vertical black bars either side, and whether there is also a black bar on top depends of how I modify the video settings.

Selecting Blank+ from the OSD always expands the picture to full width, but no amount of settings changes on the core OSD will allow me to fill the entire screen with the game image. I've tried many different setting changes in the MiSTer.ini file and then tried combinations of changes in the OSD but no luck. I must admit, I understand what some of the video settings mean, but not all of them.

So my question is, is this normal? Will the game image never fill the screen but only take up about 3/4 of it? What's confusing me is that the Workbench splash screen DOES take up the whole screen. Why? Why does one fill the screen but not both?

If I have vscale_mode=0, why does the game not fill the screen?

[Retro-Nerd]

On the Amiga you can program the intended viewable display in any size as you want. Black borders are pretty normal for most of the games. A lot of earlier games (up to 1990) were just plain Atari ST conversions, so borders are pretty much normal in PAL resolution.

Another reason for a smaller image was to save CPU performance, which allowed you then to use more graphically effects, more colors etc. without bigger slowdowns.

If you are looking for Amiga games that uses a full screen (mostly PAL overscan): a lot of Team 17 games fill the full screen, or something like "The Settlers". Jim Power probably too.

[Armakuni]

Try a game like Pac Mania which was a full screen game on the Amiga.

[emiliom]

Thanks for the replies. I'll give those games a go and see what I get. It's been a long time since I used a real Amiga on an actual CRT monitor so I forget exactly how it used to look. I guess I was fooled a bit by Amiga Forever which I've been using for a while and blows everything up to full screen.

[emiliom]

Now that I think of it, when first using Amiga Forever I also had a smaller image area, in particular I'm thinking of Gods as I remember that one distinctly, but I 'fixed' that with an option to stretch to fill which is no doubt where I've been getting confused. If I change my options in Amiga Forever to preserve aspect ratio and use integer scaling I also get black bars and a much smaller play area for Gods. Only thing is in AF the image is centred, and with the MiSTer it's offset a bit towards the top. Not a huge amount but it's noticeable.

I haven't got The Settlers, or strangely any Team 17 games, but I just tried Pacmania and indeed I get virtually a full screen image. And if I change my settings on Amiga Forever to match I also get the same result. So yes it all seems to be normal except that in the MiSTer I have this offset upwards.

Thanks again for the help.

[limi]

Additionally, over HDMI (and I know this is not what you’re asking about you can apply 5× scaling, and we do it on a per-game basis in AmigaVision — this also covers why there is a black area at the bottom, using Gods as one of the examples:

https://amiga.vision/5x/

Amiga monitors also had ways to resize and move the image, and we would often adjust this based on what game we were playing.

gods5x.gif (120.14 KiB) Viewed 2466 times

[akeley]

So yes it all seems to be normal except that in the MiSTer I have this offset upwards.

This is actually how it is in PAL on real hardware. And MiSTer displays 1:1 Amiga image over analogue. Most micros had borders but the image was more or less centered, Amiga is an a exception.

Examples: 1 2 3

Flight Of The Amazon Queen (Amiga 500)(RGB)(PAL)(Sony KV21FT1K)(!).jpg (2.16 MiB) Viewed 2465 times

One on One (Amiga 500)(RGB)(PAL)(Sony KV21FT1K)(!).jpg (1.25 MiB) Viewed 2464 times

Last Ninja 2 (Amiga 500)(RGB)(PAL)(Sony KV21FT1K)(!).jpg (1.59 MiB) Viewed 2463 times

[FoxbatStargazer]

Yeah in addition, if you are using real analog output, most of the video settings do nothing. They are there to tweak HDMI/vga_scaler output.

Definitely a core I wish had CRT vertical and horizontal adjustments like some of Jotego's arcade cores!

[emiliom]

Additionally, over HDMI (and I know this is not what you’re asking about you can apply 5× scaling, and we do it on a per-game basis in AmigaVision — this also covers why there is a black area at the bottom, using Gods as one of the examples:

That's very interesting. Sounds like it must have been a lot of work as well given you went through the entire Amiga catalogue! I must admit, I do like the significantly bigger display area. I went with my VGA out because I had the VGA port spare on my monitor and it worked out well to have my PC on the HDMI and Multisystem on the VGA. Also I really fancied using the VGA port just to use a more retro connection for a change! I'm a bit limited on space or I would love to get an old Philips monitor like the one I used to have (basically the Commodore monitor that just wasn't rebadged as Commodore) and plug the VGA out into that. Anyway, I could always get a KVM switch and go with HDMI for my current LCD monitor.

So this is downloadable from archive.org?

[emiliom]

So yes it all seems to be normal except that in the MiSTer I have this offset upwards.

This is actually how it is in PAL on real hardware. And MiSTer displays 1:1 Amiga image over analogue. Most micros had borders but the image was more or less centered, Amiga is an a exception.

Funny thing is I don't remember there being such a big black area at the bottom. I know it's game dependant, but I just can't recall that. I just looked it up and I had the Philips CM8833. I'm wondering would it have auto centred the image? Maybe that's why it's not familiar. Or maybe it was just too long ago for me to remember

[emiliom]

Yeah in addition, if you are using real analog output, most of the video settings do nothing. They are there to tweak HDMI/vga_scaler output.

Definitely a core I wish had CRT vertical and horizontal adjustments like some of Jotego's arcade cores!

Yeah, I didn't notice that at first. Then I started reading the comments properly instead of skimming them!

[limi]

Funny thing is I don't remember there being such a big black area at the bottom. I know it's game dependant, but I just can't recall that. I just looked it up and I had the Philips CM8833. I'm wondering would it have auto centred the image? Maybe that's why it's not familiar. Or maybe it was just too long ago for me to remember

The CM8833 is pretty much identical with the Commodore 1081/1084 (which were the most common monitors used with the Amiga), and they behave in the same way.

The black area at the bottom is definitely there with the original monitor, it’s just that you don’t remember.

Later games (e.g. Alien Breed II, Pinball Dreams) used the full height of the PAL resolution, but most games didn’t.

[limi]

This is actually how it is in PAL on real hardware. And MiSTer displays 1:1 Amiga image over analogue. Most micros had borders but the image was more or less centered, Amiga is an a exception.

Examples: 1 2 3

Indeed — except for #2 in your examples, that’s a game from a US game publisher (Electronic Arts), and should be run in NTSC. It will then fill the screen :)

[akeley]

Indeed — except for #2 in your examples, that’s a game from a US game publisher (Electronic Arts), and should be run in NTSC. It will then fill the screen :)

Sure, but if you were an Amiga kid in the PAL zone back then, that's what you'd most likely see regardless of a game's origins :)

The whole PAL vs NTSC thing is a bit of a rabbit hole anyway. It's not always crystal clear what the intended resolution was supposed to be, and then you also have the nostalgia factor clouding the issue.

A few years ago I went on a big kick of trying to use strictly "proper" resolutions but eventually gave up, because trying to research it all and decide if I was actually happy with the result was too time consuming. These days I mostly just use PAL - I guess for old times' sake - though there are some games I will only accept in NTSC.

[limi]

The whole PAL vs NTSC thing is a bit of a rabbit hole anyway. It's not always crystal clear what the intended resolution was supposed to be, and then you also have the nostalgia factor clouding the issue.

It’s not that complicated (although of course people would run NTSC games like Defender of the Crown incorrectly in PAL at the time since their A500s didn’t have an obvious software-based way to switch into NTSC mode) — US game publishers like EA and Cinemaware are quite obviously made for and in NTSC resolutions and CPU speeds, then there are the Atari ports (which end up being aspect correct in NTSC even though they might have been European software houses because of the Atari’s 320×200 default resolution), and then a few other edge cases. It’s eminently doable, although a hassle to keep track of if using ADF disk images as opposed to dedicated and verified WHDLoad configurations.

A few years ago I went on a big kick of trying to use strictly "proper" resolutions but eventually gave up, because trying to research it all and decide if I was actually happy with the result was too time consuming. These days I mostly just use PAL - I guess for old times' sake - though there are some games I will only accept in NTSC.

Which is why we take care of that for you in AmigaVision with the per-game scaling and NTSC/PAL/PAL60 modes — we might of course have missed some game configurations still (and please do file bugs if you find any!), but the majority launch in the correct mode :)

[akeley]

It’s not that complicated (although of course people would run NTSC games like Defender of the Crown incorrectly in PAL at the time since their A500s didn’t have an obvious software-based way to switch into NTSC mode) — US game publishers like EA and Cinemaware are quite obviously made for and in NTSC resolutions and CPU speeds, then there are the Atari ports (which end up being aspect correct in NTSC even though they might have been European software houses because of the Atari’s 320×200 default resolution), and then a few other edge cases. It’s eminently doable, although a hassle to keep track of if using ADF disk images as opposed to dedicated and verified WHDLoad configurations.

Well, my personal opinion is that it's not really that straightforward. While there are no doubt many "certified" cases, the rest dwells in the realm of subjectivity and depends on people in modern times making judgements about the old ones. That is never 100% guaranteed, even though of course you might get good results (but so can experimenting with PAL-in-NTSC in general). But, there are simply too many uncertain variables involved - eg, some USA games could be meant for European market because of its dominance, "Atari ports" might look ok but run weirdly in NTSC, there might be games which have originated on completely different platforms, and so on.

Then you have the nostalgia factor, meaning that for some people some games will only look "correct" the way they looked +30 years ago - squashed and moved to the top ;)

Which is why we take care of that for you in AmigaVision with the per-game scaling and NTSC/PAL/PAL60 modes — we might of course have missed some game configurations still (and please do file bugs if you find any!), but the majority launch in the correct mode :)

Thanks, but I prefer to roll my own ;) and, as a strictly-CRT user, like to make choices on a per-game basis. Though, I do find AV to be a very useful resource myself and often recommend it to others too. It's definitely better suited for new users who just want to play games via a nice frontend.

[FoxbatStargazer]

The whole PAL vs NTSC thing is a bit of a rabbit hole anyway. It's not always crystal clear what the intended resolution was supposed to be, and then you also have the nostalgia factor clouding the issue.

It’s not that complicated (although of course people would run NTSC games like Defender of the Crown incorrectly in PAL at the time since their A500s didn’t have an obvious software-based way to switch into NTSC mode) — US game publishers like EA and Cinemaware are quite obviously made for and in NTSC resolutions and CPU speeds, then there are the Atari ports (which end up being aspect correct in NTSC even though they might have been European software houses because of the Atari’s 320×200 default resolution), and then a few other edge cases. It’s eminently doable, although a hassle to keep track of if using ADF disk images as opposed to dedicated and verified WHDLoad configurations.

Now this is a can of worms, because the PAL and NTSC aspect ratios differ on the ST, in spite of being the same resolution!