Re: EGA Card Restoration Attempt

Posted on 2020-08-25, 09:04

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

It is ALIVE!!! Holly cr*p I am shocked that it worked on the first try. I uses a 27C512 flash that I had. Duplicated the 16K BIOS with "COPY" command 4 times, and flashed it. Verified that the DIP is in monochrome mode as per these docs: https://arvutimuuseum.ee/th99/v/I-L/50064.htm, and it just …

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Re: EGA Card Restoration Attempt

Posted on 2020-08-24, 18:20

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

Well, if you can source the original BIOS, that will obviously simplify things a lot! In combination with a logic analyzer, you could even find good DIP switch settings via trial and error. (You should still make sure that they do not short anything out. With hardware from that era you never know.) …

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Re: EGA Card Restoration Attempt

Posted on 2020-08-24, 18:14

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

Question is, can those cards work without a BIOS? if not, where can I get my hands on a compatible one? I don't currently have an EGA capable monitor, but I do have a 9 pin monochrome one. I tried using it, but obviously nothing showed, and I also learned that it can be dangerous to the monitor if …

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Re: Redefined Color palette in CGA games in VGA like the Alleycat patch.

Posted on 2020-08-24, 12:00

by

by Benedikt

in Milliways

in Milliways

Of course it is possible. The VGA is still a VGA, after all. However, when it comes to choosing from the EGA colors, you have to program the hardware registers, directly, because IBM did not make the BIOS functions available in CGA mode. The same might apply to the VGA RAMDAC palette, but I'm not …

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Re: TNDLPT : Tandy Sound on parallel port

Posted on 2020-08-23, 17:23

by

by Benedikt

in Marvin \ Sound

in Marvin \ Sound

The Planet X3 update package with native TNDLPT support, among other things, is currently awaiting approval and will most likely be published within the next couple of days. It omits automatic un-muting for technical reasons, but that should not be a big obstacle.

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Re: Newly written driver(s) for Sierra's Creative Interpreter – Starting with Plantronics ColorPlus

Posted on 2020-08-23, 17:16

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

Yes, namely the 320x200 16-color mode on a CGA screen. You'd be the first one to test it on such a machine, but I don't expect any hiccups. There is a list of known-working games in one of my earlier posts.

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Re: Newly written driver(s) for Sierra's Creative Interpreter – Starting with Plantronics ColorPlus

Posted on 2020-08-22, 11:18

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

Apparently, the engine benchmarks the video driver and enables additional effects like water waves and flying birds when the driver is faster than a certain threshold. I had to switch the PCem VM from a 12MHz 8088 to a 10MHz 8088 to make it playable, again. The cursor drawing code, on the other …

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Re: Newly written driver(s) for Sierra's Creative Interpreter – Starting with Plantronics ColorPlus

Posted on 2020-08-21, 20:08

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

The LUT-based speed optimizations that I applied to the PCPLUS driver a couple of days ago have a funny side effect: They cause King's Quest I SCI to run slower than before. Apparently, the engine benchmarks the video driver and enables additional effects like water waves and flying birds when the …

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Re: Newly written driver(s) for Sierra's Creative Interpreter – Starting with Plantronics ColorPlus

Posted on 2020-08-19, 16:21

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

Apparently the ATI Graphics Solution cards support an extended plantronics mode that does 640x200x16. Is there any chance to support the Sierra EGA/VGA games that use EGA 640x200x16 to emulate 256 colours? While I'm quite familiar with both, programming the Graphics Solution's 640x200x16 mode and …

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Re: Newly written driver(s) for Sierra's Creative Interpreter – Starting with Plantronics ColorPlus

Posted on 2020-08-16, 09:06

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

Indeed. All in all, some twenty titles should work with this driver. The API/ABI of the SCI1/SCI1.1 256-color drivers apparently isn't all that different, either: The engine's internal frame buffer that the driver has to copy and convert rectangles from has 320x200 8-bit pixels rather than 320x200 …

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Re: Newly written driver(s) for Sierra's Creative Interpreter – Starting with Plantronics ColorPlus

Posted on 2020-08-15, 11:37

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

The list of known-working games is now as follows: Codename: ICEMAN Conquests of Camelot Hoyle's Book of Games 1 Hoyle's Book of Games 2 Hoyle's Book of Games 3 King's Quest I (SCI) King's Quest IV Leisure Suit Larry 1 (SCI) Leisure Suit Larry 3 Mixed-Up Mother Goose Police Quest II Police Quest III …

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Re: Newly written driver(s) for Sierra's Creative Interpreter – Starting with Plantronics ColorPlus

Posted on 2020-08-14, 17:43

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

The PCPLUS driver omits the actual scrolling just like the official CGA driver, but it never produced any graphical glitches like the hacked PC1512 driver.

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Re: Newly written driver(s) for Sierra's Creative Interpreter – Starting with Plantronics ColorPlus

Posted on 2020-08-14, 17:30

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

There was a copy-paste bug in the restore_background helper function. With that resolved, the driver does not seem to produce any further graphical errors. The following games definitely work: King's Quest I (SCI) King's Quest IV Space Quest I (SCI) Space Quest III Codename: ICEMAN Quest for Glory I …

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Re: Which Sierra games can use the PC1512.DRV so they have 16colors with an Amstrad 1512 system?

Posted on 2020-08-14, 09:54

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

It works! (Somewhat. Still buggy, but no freezes.) Patching instructions: Change the byte at offset 10h from 1Bh (27) to 19h (25). This shortens the descriptive string that precedes the call table. Remove two bytes (the 's.') at offset 2Ah and insert the two bytes 28h 08h (the new pointer) at offset …

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Re: Which Sierra games can use the PC1512.DRV so they have 16colors with an Amstrad 1512 system?

Posted on 2020-08-13, 21:29

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

As mentioned in the other thread, the indeed missing 10th function that some games need is a scroll function, but can be implemented with this minimal stub: Copy code to clipboard 1 mov si,di 2 jmp update_rect We should be able to patch that into the PC1512 driver binary, as well.

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Re: Newly written driver(s) for Sierra's Creative Interpreter – Starting with Plantronics ColorPlus

Posted on 2020-08-13, 20:40

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

That was easy! This is a valid stub implementation for the scroll function: Copy code to clipboard 1 mov si,di 2 jmp update_rect It doesn't really scroll, but CGA320M doesn't do that, either.

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Re: Newly written driver(s) for Sierra's Creative Interpreter – Starting with Plantronics ColorPlus

Posted on 2020-08-13, 19:38

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

Alright. So I got hold of the King's Quest I SCI remake and interestingly, it will lock up even with the original color CGA driver copied over from King's Quest IV. Maybe they added another function to the call table? Let's have a look... EDIT: A quick look with a hex editor confirms that. The call …

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Re: Newly written driver(s) for Sierra's Creative Interpreter – Starting with Plantronics ColorPlus

Posted on 2020-08-13, 16:35

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

ooh nice!!! I recently started messing with the Amstrad PC1512 and sierra's PC1512.DRV and found some games to be working fine with it.. a couple produce game breaking issues though like KQ1 remake (driver does not support scrolling of 1st screen, weird issue) or SQ3 that has unreadable text The …

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Re: Which Sierra games can use the PC1512.DRV so they have 16colors with an Amstrad 1512 system?

Posted on 2020-08-11, 16:07

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

This is weird. The driver isn't supposed to do that. It is supposed to copy rectangular areas from the engine's device-independent off-screen buffer to the screen. Nothing more.

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Re: Which Sierra games can use the PC1512.DRV so they have 16colors with an Amstrad 1512 system?

Posted on 2020-08-11, 14:19

by

by Benedikt

in Marvin \ Video

in Marvin \ Video

My guess was wrong. Turns out that the call table has all 9 entries and that my disassembler was confused. So apparently, there is indeed a hardware scrolling implementation, but it's broken. (But can still be bypassed by pointing straight to a ret!)

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