Space Quest 1 (AGI) - DOSBox - And Different Screen Sizes.

[Tawmis]

So, this may be in other AGI games too - but I noticed, when DOSBox captures (video) of the normal screen (say where Roger is walking around), the resolution captured is 320x200.

However, if you go into the Inventory screen (TAB button), the capture - just for that is 640x400.

It shouldn't matter when I save it all as 320x200 (since 640x400 is 1:1 1/2 the resolution).

Just thought that was odd that the game, within itself, appears to change resolution. (It's the same, for example for the intro - where it's all text, and then when it talks about the Astral Body in the Korona (sp) alien lab thing)

[Collector]

Odd. If Qbix sees this perhaps he might know why. But he does not see to visit here much these days.

[notbobsmith]

So, this may be in other AGI games too - but I noticed, when DOSBox captures (video) of the normal screen (say where Roger is walking around), the resolution captured is 320x200.

However, if you go into the Inventory screen (TAB button), the capture - just for that is 640x400.

It shouldn't matter when I save it all as 320x200 (since 640x400 is 1:1 1/2 the resolution).

Just thought that was odd that the game, within itself, appears to change resolution. (It's the same, for example for the intro - where it's all text, and then when it talks about the Astral Body in the Korona (sp) alien lab thing)

This is interesting. I've wondered why the screen does something "dramatic" whenever you call up the inventory screen. As if the video mode changes or something. Maybe that has something to do with it.

[Collector]

Of course when the RBT videos in KQ7 play in DOSBox, they are about half size of the game.

[Tawmis]

Some examples.

SQ1Intro.png (19.58 KiB) Viewed 3393 times

[Qbix]

The game "gamescreen" is mode 0xD and when you press tab it switches to mode 1
http://www.delorie.com/djgpp/doc/rbinter/it/10/0.html

mode 0xD is 320x200 (which scaler=normal2x to 640x400)
mode 0x1 is 320x400 (or 360x400 with 9 dot fonts) doublewidth, which gets scaled to 640x400 as well, but they are not the same

[Qbix]

For Mode D, DOSBox reports this:

Code: Select all

  41080026: INT10:Set Video Mode D
  41194467: VGA:Width 320, Height 200, fps 70.086303
  41194467: VGA:double width, double height aspect 1.200000

For mode 1, (in 8x16 font mode) DOSBox reports this:

Code: Select all

  85690159: INT10:Set Video Mode 1
  85838728: VGA:Width 320, Height 400, fps 70.086592
  85838728: VGA:double width, normal height aspect 1.200000

the double width+height "cancel out" and thus it's get saved as 320x200
With either double width or double height, they don't get canceled (by DOSBox) and the result gets saved as the big resolution (so (2*320) x 400)

[Tawmis]

Cool info, good sir. Glad I asked.

[notbobsmith]

This is very interesting. I always wondered why the AGI games "glitched" like that when viewing the inventory screen, even on native hardware back in the day.