Jazz Jackrabbit DOS 6.22 Trident TGUI9440 486 \ VOGONS

Jazz Jackrabbit DOS 6.22 Trident TGUI9440 486

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First post, by AmbassadorCosh

Posted on 2023-06-10, 20:01

AmbassadorCosh Offline

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Joined: 2022-12-20, 13:11

Running pure DOS 6.22 on the following rig

486 DX2/80 CPU (40 MHz bus)
-UM4980 VLB motherboard, 256k cache
-16 Mb RAM (1x16Mb, 72 pin SIMMS)
-VLB video (Trident TGUI9440) 1 Mb RAM, integrated I/O

So Jazz Jackrabbit and a few PinBall Games (Epic Pinball, Pinball Fantasies) have that weird switch where menus are 320x200, whereas gameplay is 320x199.

Whenever the menu/gameplay switch happens, my screen gets squished..shrinking the screen to this weird left oriented rectangle that takes up only about half of the screen area.
If I go back to the main menu, it is fine.

The squish happens less in the Epic Pinball, Pinball Fantasies is super glitchy.

Not sure how to fix this, I've tried messing around with UNIVBE, VBEHZ (doesn't work because I don't have VBE 3.0)

Any ideas?

Reply 1 of 4, by bakemono

Posted on 2023-06-11, 08:25

bakemono Offline

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Joined: 2018-01-15, 06:56

Maybe a monitor setting could fix it. What kind of monitor are you trying to play on? Jazz works fine on Trident 9440 using a CRT.

again another retro game on itch: https://90soft90.itch.io/shmup-salad

Reply 2 of 4, by AmbassadorCosh

Posted on 2023-06-11, 14:48

AmbassadorCosh Offline

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Joined: 2022-12-20, 13:11

I've tried my IBM G54 from 1997 and my Viewsonic G225f. Same thing happens.

The funny this is, LGR JUST released a video a couple of days ago showing Jazz Jackrabbit footage

https://www.youtube.com/watch?v=vQfyQqo1644&t=585s

THE EXACT SAME THING HAPPENS TO HIM

Reply 3 of 4, by digistorm

Posted on 2023-06-11, 17:54

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Location: The Netherlands

Those black bars on Jazz Jackrabbit are normal. It uses square pixels because that video mode is based on a 320x240 video mode.

Reply 4 of 4, by Gmlb256

Posted on 2023-06-11, 18:27

Gmlb256 Offline

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Joined: 2018-04-11, 15:33

Both Jazz Jackrabbit and Epic Pinball runs at 320x240 using 60 Hz refresh rate (Mode X, not related to VESA) during gameplay. As digistorm mentioned, those black bars in Jazz Jackrabbit are normal and deliberately used to preserve the aspect ratio.

Pinball Fantasies has an option to toggle between 320x200 (VGA) and 320x350 (tweaked VGA).

None of the mentioned games has support for VESA video modes, so UniVBE and VBEHz are useless.

More info here: http://nerdlypleasures.blogspot.com/2014/09/c … mode-x-and.html

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