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Walker's Way Logo

Diary of a Game - Citadel - Part 6

Many, many thanks to Philippe Lesire for scanning and OCRing the Walker's Ways from issue 46 to 52.

Issue 46 - February 1989

To celebrate the new year 'Dangerous' Martin Walker jiggles about a bit more in the CITADEL

Thursday 3rd November After a little while in most projects there are little things that need doing which start to mount up - this is one of those days when a whole batch of them gets sorted out! My top screen splits are now rock solid whatever the vertical scroll position and however many sprites are underneath the split (fingers crossed that it stays that way!) and the bullets now emerge accurately from the middle of Monitor. The pause and quit controls are properly in situ, so I can freeze everything to spot possible future bugs as they happen.

Other assorted tweaks have been installed and tested to streamline my interrupt routines - even at this stage catering for up to 18 sprites on screen soaks up interrupt time, and some routines may have to be rethought if this time simply runs out.
Friday 4th November The next routine to be added will detect alien sprite collisions with Monitor (there's no fun at this stage unless there is some DANGER), so with streamlining in mind many sheets of paper were filled with thoughts. The initially obvious way to do it is to detect sprite to sprite collisions, and for all those out there who haven't written a game, NOBODY uses the inbuilt hardware collision detection, simply because it needs so many additional checks to tell you WHICH sprites were involved!

After thinking through various schemes. the merits of 'Look before you leap' programming were proved once again. Since my 'character bullets to alien sprite' collision routine looks for the character beneath the sprite, by simply plotting a special group of characters beneath Monitor the same routine will detect alien sprite collisions with Monitor! A neat piece of timing ensures that these will never be visible, and by reshuffling the character set the routine will simultaneously detect aliens AND their own bullets hitting walls - all with no increase in detection time!
Sunday 6th November Over the weekend much study and thought resulted in two old routines being restructured for greater speed while preparing for the new collision add-ons. This freed a little more interrupt time ready for multitudinous aliens. Incidentally, anyone who's marvelled at the number of moving objects in ARMALYTE may be interested to learn that some critical routines were completely rewritten three or even four times, each being faster than the previous - this dedication certainly shows in the final version with more aliens, more and faster bullets and bigger motherships!
Monday 7th November Today was a dream come true - if only every day could be so productive! By lunchtime collisions with Monitor were written, tested and debugged, and then I made a start on the alien movement routines. By the end of the day there were not only moving aliens but moving bullets and aliens firing moving bullets, albeit always in the same direction!
Tuesday 8th November While spending some time out in the big wide world (shopping to you!) I was horrified to notice that our local WH Smith's had apparently decimated its software stocks. It really did look as if they were winding down computer sales, so much so that I had a word with the manager, who was extremely helpful.
Wednesday 9th November On with the baddies' weaponry. Now the bullets are in motion some thought needs to be given to the fastest routine to aim them accurately in the player's direction, as well as to give them 'personality' by adding different 'looks', speeds and possibly homing characteristics. All of the day was spent adding improvements to the firing routine - firstly a delay was added to prevent firing until a short time after the trap appears. This allows enough time to react to things arriving on screen, and avoids those dreadful situations in some games when you get obliterated before you've even noticed the newcomer!
Friday 11th November Well, the first attempt at aiming enemy bullets was only partially successful. Certainly they came out in the correct direction, but with a speed dependent on how far away the player was. This meant that guns at the far edge of the screen hurled flak at you, but if you got too close to them the bullets just sat on top of the guns. Whoops! Just to show how accidents can prove fruitful, this did give me the idea of aliens dropping stationary mines to avoid. Maybe, maybe not.
Saturday 12th November The second attempt worked perfectly, so I now have accurately aimed bullets to avoid from all directions. Not a pretty sight! In fact quite a bit of time was spent simply travelling around the cities seeing how the opposition felt in action. Different speeds of both aliens and bullets were tried in order to gauge playability. Fast alien bullets rarely give the player a chance to react and avoid them. but may still work in conjunction with a depleting energy bar rather than instant death to the player, since once alerted you can take steps to remove the aggressor.
Monday l4th November Now that the basics of gameplay are working it's time to add a bit more feedback to the system. Today the scoring and energy systems were installed, and seem to work well in practice. At the moment energy is on a percentage basis. Collisions with enemy bullets and the aliens themselves drain a part of your total shield energy, which will protect you from destruction until fully depleted.
Tuesday 15th November Already interrupt time has run out in the worst possible case - ie when the maximum number of sprites is on screen and moving and firing and all the player's bullets are moving as well as the player! Reorganisation of interrupt and mainline routines seems to be the order of the day, to allow more time for baddies on the interrupt. The key thought here is that some routines absolutely MUST occur every frame at an exact scanline position (moving sprites will flicker unless moved during off screen time), but with a rethink some routines may be able to run during mainline time as long as they can occur at about once per frame to'keep up'. Suffice it to say that after rejigging two routines I've managed to regain enough time to stop the overrun - a rewarding day even though nothing new has appeared!
Wednesday 16th November Presentation of the basic game is so important I thought it high time that a few more sound effects were incorporated, along with a priority system to ensure that some sounds are more important than others. This ensures that you never fail to hear the sound of yourself being destroyed. Aren't I considerate?
Thursday 17th November Right. Time to start planning the patrol system for mobile aliens. Off you go. No, come back here when I'm talking to you. What me? Yes you! This is getting silly. Click. Engaging sensible brain module. Click. OK, while I'm thinking about that let's get out the sprite editor and see what we come up with.

(Later) Several new sprites have emerged - including a new gun turret that spits out high speed deadly dealers of doom (try saying that with a mouthful of toast!) along with a few more varieties of mobile alien. One thing that I always like to do is to add personality to different species of baddy, so each will have its own distinctive weaponry (memory and processor time permitting!)
Friday 18th November This afternoon saw me with my jaw hanging open as the homing routines were first kicked into action on screen. Try to imagine an intelligent bullet that tracks its chosen target, following it round every corner in relentless pursuit (remember Runaway with Tom Selleck?) Every faltering joystick move brings the brutes slightly closer. After dodging and weaving for over a minute in my test level and triggering more trap guns in passing I ended up with six of the brutes following me in a swarm! The only tactic found so far to dispose of them is to take the corners so tightly that the pursuers crash into the walls whilst trying to cut corners.
Saturday 19th November Well, after reorganising the interrupt and mainline routines my clever way of detecting collisions between the player and alien sprites has thrown a wobbly, so a different routine must be written to overcome this. All of this shuffling on the interrupt basically hinges on the fact that some routines must carry on regardless whilst others only need to be called occasionally - indeed it may be possible that a few may be missed altogether at times of desperate time shortage without anything being noticed (don't tell anybody!)
Sunday 20th November Will wonders never cease?

Another brief foray into the comfort of the sprite editor saw the creation of yet another static gun emplacement and then a further bout with this 'kinetic reflection' business (see last month's diary). After a session examining the methods and results - three more vicious looking mods to the code cleared up minor problems arising from yesterday's contribution. Finally, the revised piping system for an alien cityscape was entered in hex ready to appear on screen. And very nice it looks too, if I say so myself!
Monday 21st November Before I send off disks to my test pilots I must add the routine to allow mobile aliens to change direction only at junctions in the corridors, to stop them trying to crash through walls in a vain effort to catch me. This proved easy enough, and by the end of the day it's much more difficult to escape from the baddies.
Wednesday 23rd November The next chunk of code will have to make the mobile aliens slightly more intelligent. Although they now follow the corridor system, it is still too easy to lose them, so they will have to follow the player even while off screen. It's rather disconcerting to suddenly find a heavy concentration of traps ahead when you know that a squad of aliens are on your tail!
Friday 25th November During a brief foray into the sound effects editor I came up with a new breed of metallic voices that are perfect for the alien firing sounds. They now have much more 'personality' as well as sounding far more 'alien' and menacing. I'm constantly amazed how players have 'translated' the pseudo voices in HUNTER'S MOON. Not only do the aliens apparently say 'Hiya' as they spit death at you but the starcells cry 'Meanwhile' as you collect them. Not a lot of people know that!
Monday 28th November Back with a vengeance. At long last the special module has been designed that lets me design levels by scrolling round dropping traps wherever I like, rather than calculating it all by hand (or calculator as the case may be). Following a few minor mishaps in which dozens of traps appeared in the middle of walls came the serious business of a sample design session.

Planting traps in all sorts of interesting places and groupings proved great fun, but the big surprise came on leaving the game and checking the trap tables for bugs. The new level, bristling with defences and fairly bursting with baddies had (wait for it!) 55 traps! My previous top limit of 128 (or even the original 256) seems to have been VERY generous. That should free some memory for more features!
Wednesday 30th November The level designer now has many additions - it allows pieces of city to be 'dropped' anywhere in the play area and different styles of cityscape to be perused in any colour scheme. Once again in testing it another design emerged, as well as some ideas for extra 'city pieces' to add variety. Remember that as each city is constructed from standard pieces, like Scalextric, the full 16 screens of play area on each level can be specified in 64 bytes!
Thursday 1st December Unanimous agreement from my test pilots - it's more fun trying to escape destruction with 'loadsatraps' activated, so I've decided to trigger them by proximity with Monitor, rather than by actual contact. This will mean that racing about willy nilly will (those last three words sound weird!) result in furious activity in the city! After thinking it through. several routines can be restructured at the same time to save more time in the long run. This is what writing games is all about - idea/test/discard or improve. Who remember a certain Mr. Braybrook ripping out the player's sprite bullets a week before the end of the MORPHEUS diary?
Friday 2nd December A real slog today to reorganise the alien movement, firing and homing routines ready to add the proximity coding. It took 6 hours of rewriting before all were ready (with more interrupt time freed. Hooray!) The proximity routine itself was written during the time it took to assemble the reorganised source code (Oh for a faster development system!), and kicking the whole thing into action showed that all the effort had been well worthwhile. Now you can no longer creep past the traps and get away with it. Just to prove it, I tried racing around the corridors avoiding everything. I didn't last very long!
Saturday 3rd December As a follow up to my comments earlier about WH Smiths, you may be interested to learn that they have just made their main computer buyer redundant - due to falling hardware sales! And in the same issue of Computer Trade Weekly came the following quote from a spokesman at HMV Reading branch: "Next year our software stock will lessen - it just doesn't sell."

Perhaps this reflects the fact that if high street shops won't demonstrate games then real enthusiasts will buy mail order from the 'pile of boxes in the garage' supplier and save up to 30% on highstreet prices. After all, 30% IS a lot more to pay simply to see the empty packaging! Long live the good independent dealers!

See you next month.

Issue 47 - March 1989

This man is so hot you could cook your breakfast on him. Who are we talking about? It's Martin 'Axe Man' Walker and his amazing technicolour Way. How far is he into the CITADEL? Read on and find out or we'll send da boys round...


Monday 12th December My copy of ZZAP! (January issue) dropped onto the doormat this morning. The ROBOCOP demo gave me quite a bit of fun, partly because it seemed like a representative version of at least part of the final game - unlike the majority of freebies which can be such early versions that they completely put you off buying the finished product! How many tapes have you got that you carefully peeled from the front of magazines to avoid spoiling the cover, and then only loaded them up once? I've got a drawer full! It does take a little more effort on the part of the programmers and ZZAP! to organize and produce a stand alone single level demo, but when done well I certainly might buy something on the strength of it! Wouldn't you? What do you MEAN no?
Tuesday 13th December With some more additions to the all-singing all-dancing level designer the number of possible city 'pieces' has now risen to 32 (Of course when I say risen I really mean that I've designed some new ones!) This effectively allows the corridors and intersections to have much more variety, and more devious cities to be constructed (rather like getting a second set of Scalextric track pieces allows you to build more complex layouts).

Just to prove the merit of taking a total of three days to produce a 'construction set', I then produced a corker of a level in under one hour, and then completed the revisions to the metal city that were waiting. Incidentally, remember that the graphics are evolving with the game - the early diary screenshots showed them, warts' n' all (Perhaps I should show mockups produced with my ST in 512 colours. Hmmm. No. That would be cheating wouldn't it, Andrew? Tee hee!) I always remember what Paul Cooper (Thalamus supremo - sounds like a new snack to eat on toast) said about screen shots. 'Until you see it move you don't know whether it's even part of the game, and not a specially prepared artist's impression'.

Mind you, I have actually met someone who has seen the new Konix joystick. And yes - some of the previews of the artist's impression WERE printed upside down in various magazines. Not very ergonomic when the handle sticks out of the top eh?
Wednesday 14th December The proximity traps work beautifully. In fact, with the larger format floor tiles the distance can be seen more easily in terms of 'squares'. As you approach and unopened device, at a certain number of 'squares' away it activates automatically (sensing your presence) so that by the time you get alongside, it's curtains (pull the other one!) So now it's time to add some more of my original ideas for a 'boardgame' strategy.

I want to replace mindless blasting with gameplay that uses a few more brain cells. First, all the proximities were made much smaller, and the remote triggering by hitting traps with your own bullets was temporarily removed (this could be provided by a more specialised weapon). This forces you to approach more cautiously, and be more aware of each local trap. Each different type of trap can have a different proximity trigger distance - and, of course, the most useful equipment will force you to get the closest before revealing its contents!
Thursday 15th December After yesterday's improvements, it was time to package up a demo to send off to my friends and colleagues, CYBERDINE SYSTEMS, for a bit of feedback. If the postal system isn't too haywaire at the moment, there will not doubt be an informative telephone call in a few days time. Off to the post office!

Have you noticed how games which get universally bad reviews in all the magazines have quite often been in the shops for a month or two already? In 'W.H.' today I spotted GAME OVER II high in the charts. What's this, I thought? A mistery product that everyone's buying but few have seen? Then I saw the packaging - bix box/poster/high class artwork. It must be a Megagame!! And then I remembered the adverts - double page spread/available for 6 machines, and the dreadful truth dawned on me. HYPE! And then finally, after rooting through all the shelves, I came across one lone copy of INTENSITY. Its case was cracked and half missing, with the artwork bent at the corners... So this is what happens to people who bravely try to produce something new and original in the gameplay department. Merry Christmas, Andrew! (Mind you, by the time this appears in print it will be February, so perhaps that should be Happy Valentine's Day. Well, Happy February anyway!)
Friday 16th December After yesterday's public embarassment in the originality department, today I looked out my copy of MORPHEUS - I've been meaning to get back and play this a bit more for some time (Too busy working to play games, eh?). since reading AB's own tips in a certain rival magazine it seemed the time was ripe for another bash, especially to see if using disruptors really are the best way to get further into the game. Although having the disk version does allow me to save my all time high scores, it also lets everyone else see how low they are! However, after several hours of play, I only manage to progress as far as system 16 - not much of an improvement on my previous best of system 15. Back to the drawing board (any special hints for fellow diarists, AB?)
Saturday 17th December Do you remember, back in the dim and distant past, that I sent out about a dozen of my music demo disks to different software companies looking for work? (ME, not the software houses, you fools!) Well, on 11th June I sent one to Ocean in Manchester. Today I received a reply (and a cheeky one at that!) I think someone must be jesting!! Perhaps they were clearing out their desks before Christmas. But at least they replied in the end.

As for the rest... Well, Virgin sent me a charming letter. A few other companies like Activision and Thalamus got in touch and are commissioning lots of musical work. The rest didn't reply at all, but I rather expected that. Don't be discouraged if your submission doesn't get an immediate response. I'm often lucky to get through on the telephone to some companies, even after four or five attempts (although others will chat for ages - while everyone else is trying four or five times to get through in vain!) And don't expect to get your demo disks back. After all, how do you think the frisbee was developed?
Sunday 18th December On with the 'boardgame'. In line with the new developments, MONITOR now moves a 'square' at a time, and only in four directions. This proved a much better form of control, as it also ensures that your bullets are always lined up with the ennemy mobiles (Mind you, theirs always line up with you!) Another advantage is that less processor time is taken by the scrolling routines (Hooray!) Since the cities are formed from horizontal and vertical corridors the no-diagonal restriction is scarcely noticed, so it's a definite thumbs up all round - the control feels much more positive.
Monday 19th December I suspect that this week will be somewhat chaotic, being so close to Christmas, but I'll keep up the diary as much as possible (what a noble gesture!) Just as an experiment I tried making the mobile aliens invulnerable and giving them instructions to stop two 'squares' away from MONITOR. By doing this they are often perfectly positioned just out of range of the player's bullets, but ready to hit anything that moves into their line of fire.

With joystick in hand I fired up the new version of the game and prepared for action. Withing the first two minutes I got hemmed into a dead end corridor and slowly battered into submission, so a new breed of alien has now evolved that employs its own shields to protect itself unless firing - definitely one to avoid at all costs!
Tuesday 20th December Christmas shopping. The shelves of all the local software stockists are groaning under the weight of the festive releases. W.H. Smiths also have HOWARD THE DUCK and RAISE THE TITANIC in stock - I'm not sure if they've been there for ages or whether ACTIVISION have an incredibly persuasive sales force! As it's a time for peace and goodwill I'll suggest the latter. Certainly doing my Sherlock Holmes bit they all seemed to have the same amount of dust (I've never understood why this happens - it's a bit of a giveaway trying to sell something covered in dust, isn't it?)

ST and Amiga titles are now appearing more regularly in my high street, though I'm afraid that I still really have to be convinced that I'll be playing a game in three months time before forking out £25!! And once again this means... You've guessed right again - READING REVIEWS IN MAGAZINES! (I believe the correct descriptive terms for this are fab, brill and triff).
Wednesday 21st December More strategy has now evolved in the game. All mobile forces will now look 'ahead' by at least one 'square' to check for solid objects. They seem a lot more intelligent already! Given that so much action is happening on screen, I also suspect that mobiles going off screen need only have their 'going off position' stored. Although this means that they won't track you (reasonable for localised security systems) they may still be waiting if you return that way again, but with all the on screen action you'll not be worrying too much about that!

In fact, the new intelligence has to take quite a lot into account. After choosing a destination 'square', each mobile alien checks to see that it is unoccupied by MONITOR and other traps and aliens (it's safer to shoot at it than to collide with it!), as well as more solid objects like walls. This prevents overlapping sprites (it's not much good having 16 sprites on screen if most are sitting on top of each other. Er, perhaps I'd better rephrase that!) This not only helps the multiplexor but also allows more ennemy forces to surround the player, rather than ganging up on each other.
Thursday 22nd December Continuing with alien movement patterns, things are really beginning to take shape. When travelling down a corridor, the player has to take into account the placement of any traps and mobiles to determine the best route. Avoiding destruction is becoming more thought provoking and less iconoclastic (There, I've wanted to use that word all year!) The feel is just as I wanted - a hybrid of shoot'em up and board game. You can stop and consider the current positions of the ennemy, or just plough in there with your fingers crossed! This can prove tricky with certain makes of joystick - it may be best to consult your doctor!
Friday 23rd December What! Still working away? But it's nearly Christmas! And you must remember that programmers don't get paid holidays. Come on to that, they don't get paid very often at all! With that sobering thought it's time to press on regardless. By the way, I'd love to know why the ZZAP! crew keep referring to me as the 'Axeman'. Perhaps it's because my remarks are so blunt. Then again perhaps not.

Since my 'baddies' are now more clever 'baddies', I can now prepare for some strategic merriment - alien bullets are going to be deadly to other aliens! This should allow some interesting gameplay to develop, as the security installations are gently persuaded to destroy each other in crossfire.
Saturday 24th December I'll just... NO! Stop dragging me away from the computer. I MUST write my diary. Today I...

AAAGH!! Please! NO!...

(Later) I have promised not to turn the computer on again until after Christmas, or risk not getting any present at all. See you next year - unless I can sneak away while everyone else has fallen asleep on Christmas Day. I'll wait until the snoring starts and then...
Monday 2nd January Well, that was quick wasn't it? Another year has started since the last diary entry. Sorry, I'm afraid I was chained to the comfy chair on Christmas Day. How many of YOU were programming then?

The festive season seemed as usual to provide a pitched ratings battle between the four TV channels, with each side tweaking its scheduled programme starting time so that watching 'The Empire Strikes Back' would always mean missing the start of something else good on the other side. Even those lucky enough to have a video recorder are now foiled by the 'three good films at once' ploy. It must take months to organise mayhem on such a vast scale - and all so that in January the executives can see which channel ended up with biggest ratings in the lucky dip!

My prize for the 'turkey' of yuletide film viewing must be award to Walt Disney's 'Black Hole'. How many times did YOU spot the strings suspending that ridiculous robot? (And his battered chum!) As for the inter-robot aggression and rivalry, and their philosophical utterings - perhaps someone should have insisted that those involved read a little Isaac Asimov. He is, after all, the definitive author of INTELLIGENT robot stories, and the oft quoted Three Laws of Robotics. At least the spate of second rate Science Fiction films that poured out after the success of 'Star Wars' proved that it is only GOOD science fiction that makes real money at the box office. People vote with their wallets (and I don't mean bribing election officials!)
Tuesday 3rd January Time to stock up with food after the holiday break, and examine the aftermath of Christmas on the software shelves. Following my earlier comments, I've definitely decided that Activision must have an INCREDIBLE sales force - W.H. Smiths are now sporting STAR RAIDERS II in a prominent position! (but with the usual amount of dust) Boots as usual have a range of special budget bargains, although their stock of RANARAMA and £2.99 does seem to be bottomless. How many copies have you bought? And after the festive furore has died down, how many of you are now the sad possessors of a duff arcade conversion?
Wednesday 4th January Time to knock the bugs out of the new intelligence routines, and make the security systems just that little bit more DANGEROUS! After a week off, I'm just itching to get the next modules into place (or maybe I'm just itching?) Cheerio.

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