\INTRODUCTION Introduction to the Blitz 2 PD library. Acid Software plan to release many disks similar to this in the future. They will be sent to various PD libraries and uploaded to bulletin boards as they are finished Please do not distribute these programs other than making a copy of the entire disk. We have included the Blitz 2 source code to the programs in ascii format. Owners of Blitz 2 feel free to hack and plunder your way into the programs, if you make any worthwhile changes please send them down to us. Members of the Blitz User club will have the opportunity to contribute to the Blitz 2 PD disks and we will attempt to offer prizes and rewards to those contributions that help establish the Blitz 2 PD disks as the premium PD collection. Thanks go to Mark, Paul and Rod for all the work gone into Disks 1 & 2. If you'd like to get in touch write to: Acid Software 10 St Kevins Arcade Karangahape Road Auckland New Zealand Fax 64-9-358-1658 (64 is for New Zealand) Enjoy! Simon Armstrong \DEFENDER ************** * * * DEFENDER * * * ************** Welcome to yet another Amiga version of Defender. With this version, I have attempted to faithfully recreate the original Williams/Eugene Jarvis masterpiece. Sorry ARC, but your attempt just didn't do it for me! Both Defender and it's excellent successor Stargate have long been favourites of mine, and I think today's game designers could learn a lot more from having a close look at what made those games so enjoyable instead of spending time on new but ultimately pointless graphic effects. In fact, it could be argued that the power of today's computer hardware is forcing programmers and designers away from basic game design, and into a special effects contest. However, with the advent of shareware, things may very well be looking up. I fully support the idea of shareware, and strongly urge all other programmers and consumers to also offer their support. If you play a decent shareware game, THEN SEND THE DUDE SOME BUCKS! Anyway, onto the technical side of things... The ASCII source code for this game may be found in the 'defender' directory under the filename 'defender.src'. To get the game to run so smoothly, I have used an interupt driven animation routine dedicated solely to moving the player, aliens and explosions. All decision making, collision detection etc is made outside of this interupt routine, by a 'background task'. This set up means that all animation is maintained at a 50 frames a second rate, while the background task simply goes as fast as it can. This does introduce the possibillity of an alien being moved more often than checked, but in my opinion, this a good compromise for a game of this type. What do you think? All elements of the game (aliens, lasers, explosions etc) are kept in Blitz 2 'list' arrays, making adding or deleting elements very easy. However, due to the interupt routine, care must be taken by the background task when it wants to add a new element. Since an interupt may occur at any time, the possibility of an interupt occuring when an alien is only 'half' initialized arises. To avoid this, the 'alloff' and 'allon' subroutines allow the background task to disable interupts breifly, add and fully initialize a game element, and then re-enable interupts. If an interupt was to occur during initialization, the interupt will instead occur when interupts are re-enabled. Please note that the 'alloff' and 'allon' subroutines in Defender only disable and enable the vertical blank interupt. Defender also includes many display tricks available due to Blitz 2's 'Blitz' mode, which allows such effects as the smooth scrolling mountains and the double buffering. The mountains on the scanner were produced using dualplayfield mode. The score and scanner blips are drawn onto the front playfield, while the back playfield is smoothly moved back and forth with the mountains drawn on it. Since colour 0 on a front playfield allows the back playfield to show through, I have set colour 7 to black, filled in the front playfield with colour 7, and punched out a colour 0 'hole' to allow the mountains to show through in their correct position. The main game also uses dualplayfield mode, with the stars and mountains drawn onto the back playfield, and the aliens, lasers and explosions drawn onto the front playfield. This allows the use of the super quick 'UnQueue' command for erasing the front playfield graphics without disrupting any back playfield graphics. Oh, by the way, the keyboard controls for Defender are: A -> Up Z -> Down SPACE BAR -> Reverse / -> thrust RIGHT SHIFT -> fire RETURN -> smart bomb (also for joystick mode) Have fun, Mark Sibly \ZOMBIE APOCALYPSE ************************* * * * ZOMBIE APOCALYPSE. * * ================== * * * ************************* NOTE: You will need at least 1 Meg of memory to play zombie apocalypse Once Upon a Time... ------------------- Zombie apocalypse is set in a city of the future, a future where a nuclear explosion has caused vast amounts of the population to mutate into ferocious killer zombies. You, as one of the remaining unmutated survivors, must destory all traces of the zombies armed with only an automatic weapon and a handfull of grenades. So What? --------- Zombie Apocalypse was written in Blitz Basic 2 and uses the `BLITZ' mode for faster operation. The game is in 32 colours and a large number of zombies (which are 48 pixels wide and 48 pixels high!) can be drawn to the screen to a 50th with no flicker. This demonstrates the speed of Blitz Basic 2. The ASCII source code for this game may be found in the 'zombies' directory under the file name 'zombies.src'. Bye bye, Paul Andrews. ********************************* THE END **********************************