@Good_Punk:
1. Perhaps I did mix up SCI versions, but my point still stands.
2. You will probably have to get your hands on the source code or reverse engineer the relevant script files. It's been done. Unless I am very much mistaken there are fan made patches for Sierra games out there. I suggest you try contacting one of those fans.
3. Games being able to work well in different graphical modes isn't that spectacular, a lot titles not from Sierra have done this too. Why not just use the games that already work in EGA and VGA for your video?
4. Okay, just to clear up confusion on my part, which games do not work properly when trying to force the use of the EGA640 driver?

3.) The fascinating thing for me is that the art was not produced in EGA but it's all done programmatically. The driver takes 256 color VGA images and through a clever dithering algorithm produces that hi-res EGA output. Yes Sierra were not the only one doing that, it's still very cool in my opinion. These games are some of the best looking EGA games out there and they are not even EGA games. 😁 I also think it's cool because it's rather obscure as at that time almost everyone either had a VGA card or their computer would not been able to compute the EGA conversion as that is very hardware intensive. So it's not just about having different graphic mode options but how they achieved the EGA image and how good it looks.

4.) Larry 5 and Police Quest 3 and all other SCI 1.0 games don't work correctly. You can put the EGA640.DRV file in their and change the resource.cfg but the mouse cursor won't show up making them mostly unplayable.

3. I don't think downgrading VGA to EGA could be that intensive. If it were, it would be self-defeating.
4. Why would SCI 1.0 not work correctly with the EGA driver and 1.1 should work correctly? You're suggesting they tried to reimplement EGA support in version succeeding the one that just dropped that support.

3.) Yes it is very intensive. There's a lot of calculation to be done to get that VGA images converted to EGA with the diterhing. You can actually see that when you turn the Cycles in DosBox down... the game becomes much more demanding when you use EGA. And yes... it is kind of self-defeating but they probably thought it was worth it for people that still didn't get their hands on a VGA card.
4.) The EGA640 driver is not just EGA support, it's a programm that converts the VGA graphics to EGA on runtime. Older Sierra games - like Police Quest 1+2 - were natively EGA. All their art was produced in 16 colors and low resolution. When Sierra upgraded to VGA graphics the EGA cards were not able to display those graphics as these had too many colors. Thus they've invented the EGA640 driver that would allow people without a VGA card to still play these games. I don't know why SCI 1.0 doesn't support it fully but maybe they ran out of time (I guess EGA had lower priority) or it was not that easy to get the mouse cursor files to convert.
SCI 1.0 has some support for EGA640 so they were clearly working on it at that time but it took until 1.1 to actually work and those were also the first games that shipped with the EGA640.DRV file. (At least from everything I've found so far)

The only case such a driver appears to make any sense is in those cases where machine having to run the game is a CPU powerful enough to allow efficient VGA to EGA conversion but still has an EGA card in a time where newer graphics cards have become the norm. There can't have been many cases like that. Could it be that for a time it was much more affordable to buy machines with a relatively powerful CPU but a nearly obsolete graphics card?

Eco Quest 2 was an educational title, I suppose the scenario I just suggested could make sense.

@good_punk:
Should you make that video it might be a good idea of not just investigating how that driver does its thing but also why it was even created to begin with.

Peter Swinkels wrote on 2021-12-26, 13:58:

@good_punk:
Should you make that video it might be a good idea of not just investigating how that driver does its thing but also why it was even created to begin with.

That would definetly be interesting... I can try to contact some folks that used to work at Sierra... but I don't have high hopes they'll actually reply. 😅

Try contacting Al Lowe for example, his website appears to be still active. https://allowe.com/

And you could try contacting someone from Agdinteractive. I might be able to contact someone I knew years ago. I make no promisses.

Try browsing this website:
https://helmet.kafuka.org/

It looks like a late 90's site but there is SCI related stuff there.

Peter Swinkels wrote on 2021-12-26, 13:58:

There can't have been many cases like that. Could it be that for a time it was much more affordable to buy machines with a relatively powerful CPU but a nearly obsolete graphics ?

My friends mother bought an early Packard Bell 486sx with onboard oak vga

In the case of VGA games many wouldn’t work.

He had the original VGA release of Monkey Island had both 5 1/4 EGA and 3.5” vga Versions
Luckily for him he had both floppy drives as the vga version wouldn’t run but the EGA version would.

My antique Tandy 1000rlx however ran the VGA version fine and had better sound

My guess is that his experience wasn’t uncommon as I encountered several friends with janky “VGA” cards in the dark ages
that didn’t seem to work with every game

What year are we talking about? My dad bought a 386sx in 1991 with a VGA card that worked fine.

Peter Swinkels wrote on 2021-12-26, 19:36:

What year are we talking about? My dad bought a 386sx in 1991 with a VGA card that worked fine.

His mothers system was from 1991 or early 92
My Tandy was likely only months newer and everything worked fine.

Garbage VGA implementations were sold through the early 90’s

That doesn’t mean there weren’t plenty of proper cards but cheap bad ones existed.

Ah, the same today. "Neighbor: My computer broke after six months! Me: What did it cost? Him: $300,-! Me to myself: mine cost $800,- and still works without a hitch after 8 years!" Pay nothing, get nothing.

Peter Swinkels wrote on 2021-12-26, 16:25:

Try contacting Al Lowe for example, his website appears to be still active. https://allowe.com/
And you could try contacting someone from Agdinteractive. I might be able to contact someone I knew years ago. I make no promisses.

That's cool, I'll give it a try

Peter Swinkels wrote on 2021-12-26, 16:54:

Try browsing this website:
https://helmet.kafuka.org/

It looks like a late 90's site but there is SCI related stuff there.

And thanks I've found some interesting stuff there.

So it there was at least an official EGA version of Larry 5... you can find a few youtube videos on that. That version didn't use EGA640.DRV but was hand-crafted. So I guess back at SCI 1.0 times Sierra still invested time into EGA version and with SCI 1.1 they switched to the driver to save time for an actual EGA version. Or something like that.

Too bad that the Larry 5 EGA version is really hard to come by, but I can include the clips from youtube I've found and credit the source I guess. 😀

That's great. Leisure Suit Larry 5 EGA? I need to look into that.

Ok, seems like Al Lowe doesn't exactly know why they used the EGA640.DRV either. 😄

Al Lowe wrote:

I wasn’t involved with that driver’s development, so I’m not a good source for you. But there’s one thing I know about AGI and SCI: they were continually evolving, so often that you couldn’t use a driver from May with an interpreter from June, for example. We got new versions almost weekly.

But yes: the goal of all those drivers was to allow non-programmers like me to create games at a high level without delving into the underbelly of each machine’s graphics, music, and disk peculiarities.

I think it's cool he actually wrote back so soon. You could try contacting someone else but I have no suggestions. Why not try looking through a game's credits?

Oh, and I found a Youtube video about LSL5 EGA. Too bad getting a copy is going to be nearly impossible.

Peter Swinkels wrote on 2021-12-28, 10:38:

Oh, and I found a Youtube video about LSL5 EGA. Too bad getting a copy is going to be nearly impossible.

Nowhere near that difficult, but probably not cheap. https://www.ebay.com/itm/363445781749
Just make sure there are pictures of disks that specify 16-color, as the specs on the box could more easily be inaccurate.

@ripsaw8080: $100,-? I don't want it that badly.

I've finally finished the video... you can find it here:
https://www.youtube.com/watch?v=ZGjCLLaYFKA 😀