Steven Seagal's Atari ST Web Site

Steem

"Driven to Emulate"

 

  Here are some cool demos that run better in new versions of Steem. 

 

 
 

Best Part of the Creation

 
 

 
  Yes kid, you got it. This is an uncommon demo using the medium resolution of the ST in overscan, and the borders are on holidays. This demo takes advantage of larger borders, which was the first reason I took the trouble to program them. I like this silly text.  
 

 http://www.atarimania.com/demo-atari-st-punish-your-machine_22163.html

 
     
 

Beyond

 
 

 
  Steem can load this protected demo just like it did back at... V.2.0. Beyond a doubt a strange case, and a nice illustration of regression in emulation!

The Pax Plax Parallax part (the screenshot) also uses a 0-byte line trick (first handled in Hatari) to scroll the screen, if it detects you're running on a STF. On a STE, it uses the video address method. If you want to check the difference that it makes, run the demo in STF mode then switch to STE. This was a superb scroller technique and it's a pity that they found nothing interesting to say in it!

 
 

http://www.pouet.net/prod.php?which=29358

 
     
 

Death of the Left Border (STF WU2)

 
 

 
  Hey guys! It is done! This was the first demo to remove the left border on the ST and Steem is the first emulator to render it properly, hack or not. The technique used wasn't stable. In v3.4, you must use option STF wake up state 2. This could change, it's just my current theory (we're here to have fun)!

Display is much like the model (true ST), the sample music is cool too:

 
 

http://www.atarimania.com/demo-atari-st-death-of-the-left-border_26368.html

 
     
 

Dragonnels

 
 

 
  The Dragonnels demo menu reprograms the keyboard chip (aka IKBD for Intelligent Keyboard, aka Hitachi HD6301V1, its precise reference).

V.3.3 The Hatari fake emulation is copied. Because there was some trouble with the menu scrolling (my mistake, it's fine in Hatari), I added a keyboard selection hack.

V.3.4 6301 true emu (but no keyboard selection in this mode).

There's also a problem with the timing of the 68000 instruction DIVS that kept the demo from loading in Steem 3.2 (the protection depends on it). It's fixed thanks to ijor's DIV timing routines.

Those are all nice demos. I recommend Unlimited Bobs, though some would say it's an "easy" effect. It may be easy in general, here it's in overscan.

 
 

 
 

I like the plasma too.

 
 

-

 
  Option 6301 mandatory!  
 

 http://www.atarimania.com/demo-atari-st-dragonnels-demo-_26062.html

 
     
 

Forest

 
 

 
  Since v3.3, Steem displays this fine 2006 demo I call Forest (aka shforstv.exe). The harder part actually was to pass the "hardware tests" that determine on what you're running. The demo only misses some music, for example A Forest by The Cure, but it was produced to make a technical point about the ST (who has the shortest).

V3.4 can pass the test and run the demo in 3 modes: STF(1), STF(2), STE, for fun, it's exactly the same animation, only the sync switch timings are different.

 
 

Download Forest

 
     
 

Froggies Over The Fence

 
 

 
  The Froggies Over The Fence demo menu reprograms the keyboard chip. It seems to be very sensitive to IKBD timings (in v3.4). I'm not sure chosen timings in 6301 true emu mode are correct but they make Froggies work. I'm not surprised that the guy who wrote the doc for the IKBD took part in programming the menu (if I got this right).

Some disk images of this demo have a corrupt graphic in the reset screen (it never was an emulation issue). The version proposed here should be fine.

The OVR 3D demo is the most impressive, because it's in full overscan. When I "experimented" with timings, I found it's very sensitive to MFP timings, and that Steem was pretty good at them (fortunately).

Option 6301 mandatory!

 
 

http://www.atarimania.com/demo-atari-st-froggies-over-the-fence_22200.html

 
     
 

Lemmings

 
 

 
  Not the game but this cool demo (my favourite scroller), part of Nostalgia, uses 0 byte lines for vertical scrolling. As that trick wasn't handled yet, it didn't work well in Steem. That's rectified now! The Atari Boys golden logo is rather on the right, it seems to be by design. Something happening at 2+ min. made me discover the main loop in Steem, a hack that would make Linus Torvalds and Bjarne Stroustrup join forces to terminate you.  
 

 http://www.atarimania.com/demo-atari-st-nostalgic-o-demo-st-niccc-2000-special-edition_22124.html

 
     
 

Let's Do the Twist Again (STF)

 
 

 
  With this demo by ST-Connexion, we introduce the 4bit hardware scrolling technique in Steem, programs using MED/LO RES switches to shift the display. Smooth scrolling (fullscreen mode). If you don't get it, it's a hardware problem (what are those PC compared with the Atari ST?).

Sound still not perfect.

 
 

 http://www.atarimania.com/demo-atari-st-punish-your-machine_22163.html

 
     
 

Phaleon

 
 

 
  And NeXT, we have this protected "giga" demo which had Steem... fail on! (Absolutely terrible). 

Notice the "dream" specs: 32MB RAM and 406MB HD!

 
 

http://www.atarimania.com/demo-atari-st-phaleon-gigademo_22151.html

 
     
 

RGBeast (STE)

 
 

 
 

ST scene stinks. It is small. It is megalame. No magic.

It's not me saying this, it's the dude who made this exceptional plasma demo (aka RGB Ruler). Say it with rasters! Only Steem 3.4 can tame this aggressive beast for now.

Note that it is a very demanding program for Steem. At each colour palette change, and there are a lot on each line, some commanded by the blitter, some by the CPU, Steem must update the display.

As usual for scrollers, fullscreen with vsync will give you a better experience (vsync in window mode depends on your hardware - interpolated scanlines may help), but this will increase CPU use even more.

 
 

http://www.pouet.net/prod.php?which=29355

 
     
 

SoWatt (STF)

 
 

 
  The problem of this impressive demo menu in Steem was a trivial case of STE detection. But now it behaves like in Hatari, it's STF-only because of a bug in the demo. The nice Sync screen is also STF-only. So what? [Hey, I'm not the first one to try this joke, check the Dragon screen in the Overdrive Demo. ]  
 

 http://www.atarimania.com/demo-atari-st-sowatt-demo_22135.html

 
     
 

Super Neo Demo Show

 
 

 
  Due to a bug in MMU emulation, this super demo (the first to do overscan of any kind: the lower border, and with much class... yes that's TEX) didn't work with 1MB or 4MB RAM.  
 

Download Super Neo Demo Show

 
     
 

Transbeauce 2

 
 

 
  The Transbeauce 2 menu reprograms the keyboard controller, which is handled in Steem SSE.

Steem also needed two improvements, no less, in CPU exception handling, to be able to load this protected demo all the time. One of them is inspired by Hatari (which was the first emulator to handle the protection). And there were other complications (Trace function) for which Steem was already equipped.

This is a demo that likes max borders (one of the reasons I provide those).

The Oxygene part tests our interrupt timings, the DNT screen looks the most impressive to me. The boot screen is also very sensitive to CPU timings.

Option 6301 mandatory!

 

http://www.atarimania.com/demo-atari-st-transbeauce-ii_22202.html

     
 

Union Demo Menu (STF)

 
 

 
  OK, guys, this milestone megademo worked in Steem, but you needed to launch the emulator with option -STFMBORDER. Who wanted to do that?

It contains the first stable true fullscreen by Level 16 (which is also STF-only though).

 
     
  Update:  
  In v3.5.4, the display option '413x280' for the famous Level 16 fullscreen.  
 

 
  Claim: this is exactly as on hardware.  
 

 http://www.atarimania.com/demo-atari-st-union-demo_22252.html

STW disk image.

 
     

 

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