** Maggie 1 page / 718 words ** GemDemo AssemSoft & Dead Hackers Society Odd Skancke Email: oskancke@online.no Anders Eriksson Email: ae@wombat.ludvika.se http://wombat.ludvika.se/gemdemo/ ** GEMDEMO.JPG here Requires: Atari compatible computer, 68020 CPU or higher. 15 or 16 bit graphics mode and enough memory to load any demo modules you have installed. GemDemo is a project for making some of the most popular demo-effects on Falcon computers available to a wider audience. It's also a way to observe which computer is best suited for demo coding and to prove that GEM in assembler is cool. Over to Mr Pink... The combination of the words Gem and Demo is enough to strike fear into the heart of even the most hardened coder. All those obscure VDI and AES calls. Those convoluted ptsin and ptsout arrays. Trap #2! - The worst graphics routines known to mankind! So when DHS announced they were working on a GemDemo, expectation can be best described as "subdued" but once again they have surprised us all. On loading GemDemo you are presented with a menu bar with entries for GemDemo, File, Demos and Options. That Demos entry looks quite strange in this environment, an uncomfortable stranger in a new terroritory. There is a new kid in Dad-land, and he has got some tricks up his sleeve. The words "GEM" and "Demos" conjure up two entirely different images. When I think of GEM I see large areas of Atari green, screen redraw problems, flickering mouse pointers, cardigans, pipes (the worst possible addition to slippers), First Word, the Open University and dads! When I think of demos I'm transported to a different dimension - a strange and exciting new world where GEM-dads frown at the Demo-kids and mutter "pointless" and "a waste of time" under their breath to which I would taunt "get a life grandad!" It's unthinkable these two bitterly sectarian tribes could ever find any common ground isn't it? Well, Evil, ably assisted by Odd Skancke of Assem Soft, has turned out to be the Nelson Mandela of the demo world, breaking down the apartheid between GEM-dads and Demo-kids. So let's put our prejudices aside and let's GEM! GemDemo provides an interface for demo coders to create Modules - demo effects that are displayed in a GEM window. The beta version comes with three different effects, familiar to every DHS fan: ** UL ** * Bump Map * Tunnel Bump * Tunnel ** /UL ** Simply select an effect from the Demos menu and it's displayed in a GEM window. I was amazed by the speed of the Bump Map given the overhead of GEM. Even under single TOS you can run the three effects simultaneously. Of course the more effects you run, the slower things get. GemDemo provides a neat statistics dialog box which indicates the current frame rate and you can reset the counter in case other programs have unfairly skewed the average. You can also choose between the GEM VDI routines or direct output - which is much faster. Turning Clipping off also speeds things up, but can lead to screen redraw problems (for example, if the demo window is behind another window) and crashes if, for example, the demo window is off the screen. Windows can be dragged around the screen and even iconified. Clicking on the fuller window gadget displays a small popup menu to set the demo window to normal, double or quadruple size. Obviously, the bigger the window, the slower things go - and the effects don't look so pretty with chunky pixels! Under multitasking operating systems such as MagiC there's finally something a little more sophisticated then the "amazing" Gem Lines demo to amaze your friends! GemDemo is not only a way to bring Falcon demo effects to machines like the Milan and Hades - it could also have the reverse effect, encouraging some with PC-kids running Atari emulators to code modules for it too. Just as the 128 byte intros kicked some lazy people into action, I can imagine a few ex-Atari coders dusting down their copies of Devpac to create some GemDemo modules. GemDemo is a brilliant and innovative idea which is both amazingly quick and entertaining so let's hope more effects are ported to modules soon. Hey! How about turning the concept on its head and made DemoGEM - a demo that runs different versions of GEM in little windows!