RetroBard wrote on 2022-02-26, 07:55:

Benedikt wrote on 2022-02-21, 18:33:

I have actually looked at "The Secret of Monkey Island" before. The main problem I see is that there aren't any drivers, at all. […]
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RetroBard wrote on 2022-02-21, 15:53:

I just recently found this topic. I was wondering how hard it would be to make a PCPplus driver for the Lucasarts games?

I have actually looked at "The Secret of Monkey Island" before. The main problem I see is that there aren't any drivers, at all.
Presumably it is all in monkey.exe itself, which makes swapping out the video code way too complicated.
If it were open source, things would be different, but it isn't, and porting ScummVM to an XT-class system sounds like a terrible idea, too.

Did Monkey Island have separate executables for the different graphics modes? Or was it set by typing the graphics mode as parameter for the executable?

Monkey Island 1 (a.k.a. "The Secret of Monkey Island") had separate 16-color and 256-color releases. If I'm not mistaken, the 256-color release came out later. And as far as I know, that version doesn't have a dithered "VGA emulation" 640x200 mode, since there as already a separate 16-color release. I believe we're talking about "Monkey Island 2: LeChuck's Revenge" here, which did not have a separate 16-color release and does indeed support a dithered 640x200 16-color mode, which, if I remember correctly, is indeed activated by specifying a command-line parameter. Other LucasArts games of the same generation, such as "Indiana Jones and the Fate of Atlantis", have this same feature. It would make sense that these games would automatically fall back to this mode on systems with EGA cards. As far as I remember, there was no separate executable for this mode in these games.

I got my Schneider EuroPC repaired to running condition. I got the pcplus.drv driver and tried them with Codename ICEMAN and Leisure Suit Larry 2, which both use the SCI engine. I was able to select the Plantronics Plus driver from the settings but both games failed to run, showing just some garbage, albeit in more colors than your standard CGA, on screen. Reverting back to CGA doesn’t seem to help. I’ve tried a few other CGA games like AGI Larry and Test Drive 2 and they seem to run normally, so I gather the graphics chip is running normally. I wonder if it’s one of the video RAM chips that might be failing? I’ll try with LSL3 tomorrow, which has been tested working with the Schneider.

Problem sorted! I had one broken trace between one of the address latch chips and the video chip. Made a quick bodge and now I’m able to play the Sierra SCI games in glorious 16 colors with my EuroPC.

I was wondering if Thexder would be able to use the Plantronics driver?

RetroBard wrote on 2022-04-06, 15:17:

I was wondering if Thexder would be able to use the Plantronics driver?

Thexder (never heard of it until today) is not an SCI game. The simple answer is therefore: “no”.
Even if it did work, it would still only run at half the speed of the CGA version.

I have been thinking, would it be possible to create a 256 color VGA driver for SCI0 games that instead of dithering takes advantage of the extra colors available?

There would be the possibility to use a 16-color palette that is somewhat optimized for a particular game, but the game's internal rendering routines will still only produce 16 colors.
A VGA card's ability to display 256 colors will not change that.

@Benedikt:
Thank you for replying and sorry for the poor phrasing. Yes, I am aware of the fact you won't suddenly get new colors . What I meant is this:
From what I understand a dithered color is specified as a combination of two out of sixteen possible colors. Couldn't those two colors be combined in a video mode that offers more colors?

Hopefully, I phrased this in a way that makes sense.

The dithering happens in the game's rendering routines. You would have to try to undo the dithering by examining the pattern.
Alternatively, you could try to patch the game engine itself.

I wonder what an updated engine could do. Interlaced graphics at a higher resolution might be nice.

EDIT:
I did some searching. It looks like picture resources are vector based. So drawing the pictures at a higher resolution might work. After some searching I found a lot of SCI related stuff but no proper documentation relating the SCI0 picture resource format. Does anyone know where to find the proper documentation?

For those of you who haven't seen it yet: The 8-Bit Guy recently published a video about so-called "Super CGA" cards, including the Plantronics ColorPlus. In the video, he demonstrates the capabilities of that card by leveraging Benedikt's SCI driver.

Merry Christmas, by the way!

Peter Swinkels wrote on 2022-12-25, 09:22:

I wonder what an updated engine could do. Interlaced graphics at a higher resolution might be nice.

EDIT:
I did some searching. It looks like picture resources are vector based. So drawing the pictures at a higher resolution might work. After some searching I found a lot of SCI related stuff but no proper documentation relating the SCI0 picture resource format. Does anyone know where to find the proper documentation?

Not SCI but AGI, but an interesting read, anyway: https://hackaday.com/2022/06/13/upscaling-the-sierras/

@Benedikt:
That looks like an interesting project!

That brings me to an idea! what about making AGI engine in highres on an oldskool machine using the acceleration that the 8514/A standard offers?? that would be really cool....
Imagine that on a 286/8 or even lower with mach8 card from ATI...that would be INSANE! ...and perhaps the "filling" could be patterned or color shaded (256colors) CRAZY 😀

dr.zeissler wrote on 2022-02-26, 08:03:

There were different executables for different versions, but they supported multiple gfx-modes afaik.
The EGA Version could be used the CGA,Hercules too and the the VGA256 supported ega-hires, but I am not 100% sure.

The first part is definitely correct. And the latter is correct for Monkey 2 and Indy 4. Not sure about Monkey 1. Never tried running Monkey 1 256 color in EGA mode...

dr.zeissler wrote on 2022-12-28, 10:45:

That brings me to an idea! what about making AGI engine in highres on an oldskool machine using the acceleration that the 8514/A standard offers?? that would be really cool....
Imagine that on a 286/8 or even lower with mach8 card from ATI...that would be INSANE! ...and perhaps the "filling" could be patterned or color shaded (256colors) CRAZY 😀

AGI graphics are shamefully low-res by nature already: 160x200 (16 colors)

That's because AGI was made with portability in mind when it was created, I think.

The low-res of 160x200 is not much more than that of a late 80's gameboy,
it can be handled by most C64-esque home computers.

AGI.. 160x200
GB.. 160x144

C64.. 160x200 (16c MultiColor, FLI), 320x200 but flickering (6c IFLI, 4 MCI) and so on

Thomson MO6.. 160x200 16 colors, 320x200 16 colors (but merely 1 color per 1x8 block), hires mono
Amstrad 6128 plus.. 160x200 16 colors (32 colors with sprites), 320x200 4 colors (20 colors with sprites), hires mono

More: https://drolez.com/retro/

Here are some more platforms of the AGI.:

https://www.mobygames.com/game/leisure-suit-l … -lounge-lizards

I'm using Larry 1 as an example, here,of course. 😉

Anyway, since AGI seems to use vector graphics,
like most graphics adventure games from the 80s,
I would simply add x87 support to the driver or engine.

Using a math co-processor would make sense the most, it accelerates all these things.
On 286+, the 8087 can easily be emulated by a TSR, if no real FPU is present.

https://hackaday.com/2022/06/13/upscaling-the-sierras/

Edit: What I meant to say - AGI titles are very low-res by nature.
There's not much information, not much detail in the graphics.
The only things that could benefit from higher definition are graphics primitives.
Circles, triangles, curves etc.

Personally, I would rather go the other way round. Lower fidelity even more, so the blocky graphics are being masked.
A lossy RF connection perhaps is best what could ever happen to CGA and C64 graphics.
The loss of information and blending of adjacent pixels would create some sort of natural, "analog" filtering.

In essence, that's what Apple II and Composite CGA graphics make so appealing, despite being extremely low-res.
That "organic" or natural style of the image.
There seems to be more information than there really is.
Not sure if that makes sense to any of you. It's hard to describe.

Edit: IBM 8514/A uses a fixed resolution of 1024×768 @256c in flickering 43,5 Hz .
It also supports drawing commands for vector graphics.

There are two ways of communication, direct and via the Adapter Interface (AI), some sort of hardware abstraction layer.

It's similar to TIGA, in certain ways. TIGA uses a software interface, too.
The TIGA "driver" in Windows 3.10 makes use of it, it's some sort of a device driver for a device driver (the TIGA driver that's bundled with the TIGA board).

However, the TIGA was fully programmable, also.
Other rivals were fixed-function graphics accelerators, often.

Edit: Interesting. TIGA and 8514/A used the TMS34010 at some point. Didn't know that.

"In the early 1990s compatible 8514 boards were also based on TI’sTMS34010 chip.
All of the clones were faster, due in part to new higher density VRAM chips,
and as a result pushed the display resolution up to 1280 × 1024 with 24-bit, 16 million colors — truly a workstation in a PC."

source: https://www.computer.org/publications/tech-ne … e-PGC-and-8514A

Edit: I forgot to mention, 8514/A can be emulated by a piece of software (for ET-4000 SVGA card).
https://www.classicdosgames.com/game/Mah_Jongg_-8514-.html

Edit: Never mind. I was thinking out loud again. Sorry.