Trench is a continuation of David Robinson's trench program in the last issue of the user magazine. You fly down the trench towards the vent at its end, blasting the baddies for all you are worth and prevent Kill-O-Zap plasma bolts from flying up the tailpipe of your X-wing fighter.
Your dual 5000 Megahurt Maxi-Slorta Hyper Blasters only fire forwards (in perspective they appear to head for the centre of the screen) whereas the enemies can fire in any direction, but you have the edge on range.
At the end of the trench (approximately 6 minutes flying time) you will encounter the vent. This must be hit dead centre to cause the desired explosion. Don't forget to fly over the wall at the end of the trench or the CPC464 will demonstrate what a wonderful explosion effect it can produce!
These wonderful effects are also shown if you fly into a wall,get hit by enemy fire or fly too high when you will be rapidly picked off by fire from the surface (except at the end of the trench).
It is very difficult to blast an alien from directly above, below or to the sides due to their shielding but they eventually succumb to fire from even a slight angle.
You know how far down the trench you have gone as this is indicated by a bar in the top right corner of the screen.
Points are scored for blasting aliens, hitting the vent and (hopefully) your triumphant exit from the trench without one of those explosion effects.
Points are deducted for firing weapons around like Wyatt Earp in the O.K. Corral. Movement and blasting is done with the cursor cluster and space bar or joystick.
The closer an alien is to you the more points you get
for blasting him. The problem is that he is more likely to blast you.
All you have to do now is remember to aviod crashing into the walls and may the force be with you! A brief description of various parts of the program:
- 110 - Set keys for a fast repeat rate.
- 110 - 220 MICR style character set.
- 230 - 240 Calls up instructions, title page and sets graphics plot mode to normal.
- 250 Creates wierd noise and flashes title page.
- 260 - 300 Sets up the screen for an alien zapping session.
- 310 - 340 Initializes event timers for moving trench & end of game. Also sets graphics plot mode and launches your first fighter. If you want a shorter or longer game make the figure 1500 smaller or larger.
- 350 Check for joystick movement, key presses, furious pounding of keyboard etc.
- 360 Sees if you have run out of time yet.
- 370 Moves you again so that you go faster than the enemy.
- 400 - 420 Draws the X-wing fighter. PLOTRs prevent unsightly holes in fuselage.
- 430 - 470 This bit draws the trench.
- 480 - 530 Tidies up ragged edges from previous trench drawing.
- 540 - 560 Cycles inks 1,2 & 3 so trench appears to move.
- 580 - 630 Read keyboard or joystick so you appear to move.
- 640 Looks to see if you fired the blasters.
- 650 - 700 Various ways of blowing yourself up and getting reincarnated.
- 710 - 740 Shoot bang fire!
- 750 - 850 Various jiggery pokery to deal with th odd occasion when you actually hit any thing.
- 860 Display score (if any).
- 880 - 910 Draw the alien (Boo! Hiss!).
- 920 - 1030 Decide path of alien.
- 1040 - 1070 Put him on that path.
- 1080 - 1160 The alien strikes back and occasionally hits you (so don't get too cocky).
- 1170 - 1250 Aforementioned neat explosion effects (red for him, yellow for you).
- 1260 - 1320 Oh dear, all this fun is over. See if promising young starfighter wants another crack at it.
- 1230 As parting gift give the user readable text and a useable keyboard.
- 1350 - 1500 Stop any timers and display instructions for those who have not read the article properly.
- 1510 - 1540 Updates that curious red and yellow progress indicator and initiates wall routine when time is up.
- 1550 - 1610 Deals with joystck.
- 1620 - 1740 Print appropriately sized wall and vent without obliterating spacecraft.
- 1750 - 1780 This is when you hit 'em where it hurts.
- 1790 - 1850 and scraper without becoming an ex-fighter pilot.