======================================================================= 1 About ======================================================================= Many, many moons ago, (1979 to be specific) I was the sort of poor malnourished urchin that used to hang around the video arcades after school, probably while you were doing your homework... ;-) Even now, I can still remember that first glimpse of the game "Asteroids", the dazzling quality of those pin sharp dots of white light, the mathematical purity of the thing... At the time I didn't know what was making it work, but I knew I'd fallen in love... Anyway, while asteroids was pretty wonderful, the game that really launched the video games phenomenon was good old Space Invaders. If memory serves, the first machines were produced by Midway and used buttons for left and right, the later Taito versions used a standard joystick. My favourite invaders variant though was called "Cosmic Monsters" by Universal. As well as being a colour game, it added novel features such as reinforcements... If anyone can get hold of a rom image of CM I'd be ecstatic... As a consequence of spending so much time in this environment, I knew almost every trick in the book as far as playing the games (and how to obtain free credits!). So, when I got my first computer (zx81) , what I really wanted was a way of playing space invaders. Despite all the "advances" since then, every supposed "clone" of the game fell far short of my (admittedly perfectionist) standards. Until that is, I saw Dave Spicer's "Sparcade", I was utterly amazed, the only problem was that it meant powering up my lame PC to play it... So, a few weeks back, while in an ambitious mood, I decided to have a go at doing an emulator on the Amiga. I thought it would take a few months to complete, and that it would be best to use someone else's Z80 emulation package. After all there's no point re-inventing wheels, (not that it's ever stopped me before..) I was wrong... After much hair pulling I decided I'd need to write my own, simply in order to understand the thing. It took 3 days to write, and 4 days to debug to the point where the game actually ran. Bearing in mind I haven't used z80 in 10 years, was never that competent at it anyway, and that I had no documentation apart from Marat F.'s C source, I was amazed at how easy it was, and at how fast the code ran.. So.. here we are. The emulator is actually emulating an Intel 8080 (the z80 was a deluxe 8080 compatible), and it currently runs 4 or so games (AFAIK), albeit imperfectly in the case of Lunar Rescue. These are: Space Invaders Space Invaders Deluxe Lunar Rescue (still buggy) Space Attack II Space Invaders Revenge (still buggy) Once I have the energy, I'll probably attempt to emulate Pacman, Galaxians etc etc.. but I've no idea how easy or difficult it'll be, so no promises. Oh, and don't hold your breath waiting for sound, it's a tricky job, plus I have no idea how to use audio on the Amiga... sorry. ======================================================================= 2 Installation & Usage ======================================================================= 1) Unarchive - Then put the ArcEm drawer wherever you like. 2) Get hold of some Roms - see (*) 3) Put them in the roms drawer 4) Double click on of the icons. 5) Hit 3 to insert a coin, 1 for 1P, 2 for 2P. P to pause, R to resume. 6) Use joystick to move about etc.... perhaps pressing the fire button every so often, to add a bit of variety ? 7) Edit the ArcEm.cfg file and modify the speed to taste. 20 seems about right for my machine (28 Mhz 020), but you'll need to change it if you have a faster/slower machine. 8) After: a) Wiping away tears of nostalgia. b) Puking at the primitive graphics. (delete as appropriate) Hit Q to quit. (*) Wot No Roms !? You'll need the machine roms of course, where you get these from is a bit of a dilemma really isn't it... You could take the easy route and just grab them from a web page perhaps.. but was life supposed to be that easy ? Remember, anything that's fun and doesn't require subservience before you get your carrot is probably very naughty indeed... Right, that's my audience reduced to those with a pragmatic approach to "intellectual property", and possibly one or two rich buggers who can afford the original machines. For the sake of unreality I'll assume this program will mainly be used by the latter category. Once you get them, it's probably best if you put them in the drawer provided, which, funnily enough is called "roms". Assuming that the names of your set of roms are exactly the same as those listed in the ArcEm.cfg file, you can then simply click the appropriate icon and start playing. Otherwise, you'll have to rename the roms, or edit the names in the cfg file, whichever you find most fulfilling. One more thing, if you're having difficulties finding the roms, DO *NOT* MAIL ME ASKING FOR THEM!! Under no circumstances will I send you any. Nope, not even if you're an aol customer!! [ Clue: Try AltaVista. search for: +mame +roms ] ======================================================================= 3 Space Invaders tips & secrets. ======================================================================= Here's a few tips for playing Space Invaders, I'll assume you already know the basic strategy as far as trimming widthways first as opposed to randomly. 1) If you want to get a 300 point bonus, you need to fire 22(?) shots and then hit the "beefy" (spaceship looks like a beefburger) with shot no. 23. After this, you need to hit it with every 15th shot for a 300 every time. [Score is obviously a function of (shots fired modulo 15) ] 2) You will continue to get spaceships (or "beefies") at regular intervals until the fleet is reduced to less than 8 invaders. 3) When an invader is sitting on the very last row before it invades, it can't touch you.. You can sit under it's nose all day and not feel a thing. This forms the basis for what we called "the method", you produce a box pattern with one straggling invader to avoid being cornered, then slowly remove layers until you're ready to finish off the final few. [see method.gif in pics drawer] 4) The invaders which shoot tend to be on the extremes. So if they're uncomfortably low, don't finish off the current column, make a start on the next one before killing the top guy. 5) Every so often you get what we used to term a "dead" invader, this usually happens when you are shooting at the barriers at some distance from the fleet. Suddenly one invader freezes and becomes a dead unmoving lump of pixels.. I've no idea why, but it's a fun little bug. [See dead.gif in the pics drawer] 6) Even more rare, but much more nasty is what we used to call a "freak invasion", for no good reason the invaders would wise up to the fact that marching left and right was inefficient and simply head vertically downwards... Frightening as hell when it happens the first time. (It's never happened to me yet during an emulated game...) 7) Each wave the fleet starts at a lower initial height. I think there are 9 waves before they go back to the height of wave 2, we called this "sending them up". My record was two and a half cycles. [ Even when they go back up, by that time they are positively *spewing* missiles, so it's not that much of a relief. ] Actually "clocking" the score is much easier... I think my best was (2)4000 or thereabouts. ======================================================================= 4 Credits ======================================================================= Dave Spicer, Neil Bradley, Marat Fayzullin for their contributions to the arcade emulation scene. Diddler, Smiffy, Tucker and all my other partners in crime, who hung out down "the front" in Redcar back in the early 80's... happy days... ======================================================================= 5 Program Status ======================================================================= ArcEm is freely distributable, but remains © Andrew G Bennett. The game roms are not. Donations are welcome, but not required. If you'd like to encourage me to spend my time doing further work on arcade emulation, as opposed to my other interests, send your bribes/ postcards/whatever, to :- Andrew Bennett 6, Malham Grove, Ingleby Barwick, Cleveland. TS10 3RX Or, if, like me, you're financially challenged, just send a thank you via email... I'm a sucker for praise.. :) To ensure you get through my spam filter, mail me at: arcem@gauss.demon.co.uk On the subject of spam, you can also pick up Poppy, which is capable of killing 90%+ of UCE/Spam on my amiga web page: http://www.gauss.demon.co.uk/amiga.html This is probably the best place to look for updates of ArcEm too... =======================================================================