From Retrosoftware

Revision as of 23:39, 18 September 2009

Treasure Island by Paul Davis

License

Software license TBC

Introduction

A BBC micro conversion of Treasure Island, a fairly simple maze game from 1985 by Greg Duddle originally supplied with the Commodore Plus/4, and based on the classic 1883 novel by Robert Louis Stevenson. The aim is to explore the island, as Jim Hawkins, to find the treasure, collect certain items, and deal with any pirates that get in your way. Once you've found the treasure you must race back to the Hispaniola before Long John Silver catches up with you.

Discuss Treasure Island

Features

• Colourful mode 2 graphics
• 'Sea shanty' style title music
• 8x8 screen playable area (flip screen)
• Easy to get into and play. Tricky to win with 100% score
• Limited availability of weapons adds a strategic element
• Collectable objects give some replay value. Play once to win, again to get 100%

Status

The Plus/4 version of the game has been fully mapped.

All the graphics and music for the BBC version have now been created.

Main player sprite is currently able to move freely around the screen but no collision detection yet.

Sample Screenshots

Original Commodore Plus/4 Version

Treasure Island Commodore Plus/4 title screen Posted: 14:40, 6 July 2009

Treasure Island Commodore Plus/4 in-game screenshot Posted: 11:59, 6 July 2009

BBC Version

Treasure Island BBC screen 2c
Posted: 18:00, 7 July 2009

Treasure Island BBC screen 2d
Posted: 18:00, 7 July 2009

Treasure Island BBC screen 6c
Posted: 18:00, 7 July 2009

Treasure Island BBC screen 1h
Posted: 18:00, 7 July 2009

Treasure Island BBC sample screen showing a selection of tiles used in the game
Posted: 18:00, 7 July 2009

Sample Video

Coming soon

Development Diary

September 2009

18th September
Very little progress made this past month. Eventually managed to motivate myself back into doing some more work on the game this week.
• Spent some time designing a custom font and created the title screen and high score screen. The original game didn't feature a high score table but I think this will be a welcome addition.
• Created the graphics for the status panel. The vertical 'scroll' imagery used in the Plus/4 version has been moved from the side of the play area to a thin horizontal scroll running across the top of the screen.
• Converted the game's music and wrote a simple player routine for it. Surprisingly, it didn't take long and the results are pretty faithful to the Plus/4 version. Once again, though, the data takes up way too much memory and will need to be compressed.
• Some of the main character sprites needed to be re-drawn to reduce memory wastage and make them simpler to handle in the sprite plotter.
• Finally got the sprite plotting code to the point where Jim can be moved around the screen without leaving a pile of crap in his wake!

August 2009

10th August
Wrote the sprite plotting code for moveable characters and put in the sprites for Jim and LJS.
Now it just needs the ability to render different sized sprites and it can be used for the weapons too.

8th August
Completed the routines for compressing tile graphics. It only managed to shave off 2K (from 7K down to 5) which is slightly disappointing but it's enough to get the player sprites in there now.

3rd August
Finally able to make some more progress on the game.
Added the sprite plotting code for collectable items and enemy pirates. Still need to write a plotter for the moveable sprites: Jim, Long John and weapons.
Designed a compression scheme for the tile graphics to free up some much needed memory. It should also slightly improve the performance of tile rendering which is still a tad slow on the Elk version.

July 2009

21st July
All the screen data has now been entered. Not much memory left, just over 1000 bytes in which to fit all the game code!
Next job... putting the main player sprite into the game and letting him move around the screens.

18th July
Not much progress this past week or so due to illness.
I did manage to put in the final set of optimisations to the tile rendering code which is now almost 10 times faster than the original version.
Spent some time designing the data structures used to represent the screen maps. With that complete, I can finally make a start on putting all the screens into the game.

7th July
The graphics are now fully drawn.
Had another look at the slow tile rendering code. It's funny how when you look at things a few days later the solution seems to be blindingly obvious! Tile rendering is now 3 times faster, just about good enough for a beeb, but still too slow for the elk. I've got an idea on how I'm going to how to speed it up further which I'll try in a few days.

5th July
Started drawing the BBC graphics. About half way through so far.

4th July
Wrote some preliminary code to display sprites and map tiles. Profiling shows the sprite rendering to be plenty quick enough but the tile rendering engine is way too slow. This will need more work at a later date, but for now it's good enough to use while designing the graphics.

1st July
Mapped the Plus/4 version of the game including enemies, collectables and point allocations.