Bugs

Here are a few bugs which appear in the game.

Several of these bugs are fixed in the unofficial K240 patch, K240-Bugfix.

Ship repair bug

Repair Facility fails to properly account for shields when repairing ships. This allows small ships in hangars to increase their Armour well above their maximum. It can also prevent damaged small ships from restoring Armour granted by shields.

Once every eight days, each Repair Facility repairs one Armour to every small ship in hangars. Before incrementing a ship’s Armour, it makes two checks: that the ship does not have 0 Armour, and that the ship is not currently equal to its base maximum for its class.

However, it does not account for ships with shields, which start with above their base maximum. This has two effects.

• Ships damaged below the base Armour will only repair up to their base Armour.
• Ships with above their base Armour thanks to shields will repair up to 255. At 256, it loops back to 0 and the ship will no longer repair, and the game will effectively consider it destroyed.

For example, a Scoutship normally has 5 Armour. Repair Facility will add 1 to a Scoutship’s Armour as long as it does not have 0 or 5 HP. If a Scoutship has Shield x30 as its hardpoint, it begins at 35 Armour and will repair to 36, 37, 38, and so on up to 255 if it stays long enough in hangars. However, if it is ever damaged to 5 or below, it will never repair above 5.

A screenshot on the back of the K240 game box shows small ships with impossibly high Armour values. This may be an example of the bug. The two non-small ships shown are Transporters with 110 and 130 Armour, respectively, both of which are legitimately possible on self-built Transporters with shields in both slots. The Assault Fighters make no sense as it would require a shield in their only hardpoint slot, in addition to the repair bug. Perhaps an early build did not yet force randomly-generated ships to have a weapon in their first slot.

Thanks to drDragonSmile for discovering this bug (issue #11 on the issue tracker) as recently as 2023, and successfully implementing a bugfix. If you’d like to implement the same fix, open the file playk240 in a hex editor and go to byte offset 0x15e6e (decimal 89,710) and change the bytes 6702 to 6f02. This changes the check from BEQ to BLE, i.e. == to <=, and prevents over-repair. However, repairs are still capped to the base value without shields.

Fleet bug

Fleets will sometimes appear to jump from one asteroid to another, followed by a game crash.

When sending a fleet to an asteroid, it may suddenly teleport to the asteroid. It’s unclear exactly what triggers this. However, the ships of the fleet remain behind. If the fleet is moved again, the game may crash. Disbanding the fleet may prevent the crash.

This bug is present in the initial v1.886 release (see version history and development and release history), but analysis of the code suggests that a change to fix it appeared in the June 1994 v2.000 update. This appears to be the only change made in that version, aside from an updated version string.

Asteros depletion bug

Asteros depletes from a colonized asteroid at a rate of one unit per four days, even if no Mines have been built. This occurs in the Powerplant code, suggesting it was meant to reflect the Powerplant using Asteros ore, but the code is bugged and it just depletes Asteros.

See Powerplant for more details.

Issue #12 suggests a bugfix.

Alien scaffold bug

Clicking on an alien scaffold while in “flat” building mode sometimes causes junk to appear on screen instead of a building name.

Yards need more Bytanium

When building a ship, the construction window sometimes incorrectly reports a shortage of ore, although construction will proceed normally.

The game gradually deducts ore during the ship’s construction process. However, it reports an error if at any point there is insufficient ore to cover the total requirements.

For example, the Orbital Space Dock requires 10 Bytanium and 20 Dragonium. Suppose you sell all but 10 Bytanium, because nothing in the game but an OSD requires Bytanium, and start construction on an OSD. Once you’re down to 9 Bytanium in stores, the OSD will complain that there’s not enough, because there’s less than 10. However, construction will proceed normally.

Photon or Plasma?

The game is inconsistent as to whether photon or plasma is the most powerful. In turret buildings, Photon is described as superior to Plasma, and the game code confirms this (Photon deals 8 damage, Plasma 5 damage, and Laser 2 damage).

However, with ship hardpoints, Plasma (9000 CR) costs more than Photon (4500 CR) and is described in the manual as superior. The game code confirms that this is a mistake: Photon Cannon, despite being cheaper, is more powerful. The ship cannons deal exactly the same damage as their turret counterparts.

See Photon vs Plasma for an in-depth look at this.

Wrong blueprint

The blueprints of the Static Inducer and Warp Generator don’t match their appearance in in the build window.

In the Sci-Tek screen, the cross-shaped hardpoint is the Static Inducer, while the more cannon-shaped item is the Warp Generator. Note the Warp Generator’s reference to “cloak sequencer” in the graphic. In the Construction Yard screen, they are swapped.

Minor typos

In the missile build screen, “AREA EXPLOSIVE.” has a full stop at the end of its name, but no other missile does.

The game consistently misspells hangar as hanger. This typo previously appeared in Graeme Ing’s previous game BSS Jane Seymour, aka Spacewrecked (see video).

The language select screen reads English, “Francais”, and “Deutsche”. The last two should correctly be spelled Français and Deutsch.

The blueprint purchase screen reads “THANKYOU”, which should be two words, “THANK YOU”.

Selenium calculation bug

A small bug appears to generate the amount of Selenium incorrectly.

As mentioned in asteroids and ore, each asteroid has a percentage chance to have each ore. The amount of each ore is randomly chosen between a minimum and maximum value. It’s calculated using the formula min+rand(1+max-min), where rand(n) is a function that selects a random integer between zero and n-1.

However, for Selenium, the maximum amount (100) is lower than the minimum (500), resulting in calling rand(-399). Despite this, the random function effectively treats negative input values as positive. This returns a random value from 0 to 398, giving a range from 500 to 898.

Missile sprite animations missing

Missile sprites only appear on the missile build screen. However, since the game is paused in build screens, animations also freeze. In fact, missile sprites for Scatter, Virus, Stasis and Antivirus have animations, which the player never sees.

All missile animations and most sprite animations are handled using palette colors 14 and 15, which alternate between #700 and #FF2 (dark red and yellow, respectively). This trick is also used to animate ship engines, the Static Inducer effect, the blinking lights on ships and buildings, and even the animation of the Mine and Deep Bore Mine.

Ax’Zilanth teleport selection

The Ax’Zilanth ability to teleport their asteroids is granted by a building called the Mass Displacement Podule, which has a 1% chance per day to trigger, except on missile-firing days.

For some reason, however, the asteroid to be teleported is randomly selected. Additionally, the asteroid which is teleported does not actually require a Mass Displacement Podule, since the building count references the currently indexed asteroid instead of the randomly-selected asteroid. The latter is probably a bug.

For example, suppose the Ax’Zilanth have 3 colonized asteroids, and 2 have Mass Displacement Podules. Each of the two Mass Displacement Podules have an independent 1% chance each day to activate. Whenever one activates, the asteroid which is teleported is randomly selected from all three.

Space Dock armour bug

Ships built in the Orbital Space Dock suffer a -1 Armour penalty for each empty or absent hardpoint slot. This includes the Orbital Space Dock itself.

For example, a Terminator with all four hardpoint slots filled with weapons will start with 48/50 Armour, which is a -1 penalty for each of the other two of six slots which a Terminator lacks. With all hardpoint slots empty, it would start with 44/50 Armour, which is -1 for all six slots.

The bug occurs because empty hardpoint slots are represented by 0xff, representing -1. The OSD attempts to add the Armour value for hardpoint -1, returning the previous value in memory, which happens to be 0xffff, also representing -1. The Construction Yard for small ships doesn’t suffer from this problem because it contains a check to skip negative values.