Missing Link Map Editor

The Missing Link Map Editor (EDDY) is used to set up the scrolling maps that the commands “world” and “landscape” uses. It works similar to the MAP accessory that comes with STOS only we have a larger area.

So what does this map look like then? Well load one of the example files on the missing link disk and have a look. Try landscape.bas and run it. As you can see, pushing the joystick the screen scrolls up and down. This screen is made up of a set of blocks called landscape blocks which were made from sprites using the MAKE program.

Let’s use EDDY to create our own simple map. Load EDDY and run it. You will be presented with the editor screen, this is where our blocks are to be placed to build up a scrolling map as in the landscape.bas file. Press SPACE to go to the editor. From here we see various options which we’ll look at soon. But first things first. We need to create some blocks to make the zone. So exit from EDDY and load up the MAKE program, ie: load “make.bas”. Run it and enter the STOS disk and select the load sprites option. Load the file MAP.MBK, this is a sprite bank containing sprites that could be used to make a game like gaunlet. Convert the sprites to world blocks making four images of each sprite. Once it’s done, save the file as world blocks under the name of WBLOCK.MBK.

Reload EDDY, run it and go to the editor. Click on the load world blocks option and load the newly converted file (WBLOCK.MBK). Once this is done the blocks will line up along the top of the screen. Click on one to select it, then press SPACE to continue.

Note it is a good idea to insert a blank space in the sprite bank before converting it. You can now click on this with the right mouse button to assign it to that button. So now if you put a block on screen then you can erase it by placing the mouse pointer over that block and pressing the right mouse button.

Once you’ve clicked on a block to use and pressed SPACE you will be in the editor window. Place the mouse pointer somewhere and press the left mouse key. The block appears at that position. Click on it with the right mouse button if you’ve assigned a blank block to it and the block will vanish. Useful if you make a mistake.

Note that pressing UNDO will exit the program and pressing * on the number keypad will give you online help. I think this option works on the compiled version only though.

Making a scrolling map is like making a map with the map designer. Just click on the left mouse button to place the block and right mouse button to erase it. Note that the first block in your sprite bank must be a blank space as EDDY uses this block to erase blocks from screen, otherwise the map area is filled with these blocks. At the bottom of the screen are the co-ordinates of the mouse pointer. Try moving the pointer about and you’ll notice that they go further than normal screen co-ordinates..X 319 Y 199. So as you can see…..the map area is larger than the actual screen.

When making a landscape map then make sure the blocks at the end of the screen start at X co-ordinate 304, if you go beyond this then the blocks on the right hand side will be cut off in the landscape routine. Note that due to a bug in this program you can’t load landscape blocks into EDDY so in order to create a landscape map you must first make your sprites into world blocks, make the map, make the sprites into landscape blocks and use them in your routine.

Note you can actually build up a series of blocks on screen then make a copy of them to paste elsewhere. Lets say you made a small maze and you wanted to place that elsewhere on the map then position the mouse at the top left hand corner of the maze and press F1. Then postion the mouse at the bottom right hand corner of the maze and press F2.

You have just captured this maze. Note it works like the cut and paste feature in art packages. If you press F3 then that block will be erased from memory. If you wish to paste the maze block somewhere else on the map then position the mouse pointer where you want it and press F4. Note that when you cut the block a stream of colour covered it telling you how much of the area was captured.

This captured block is known as an area, and it can be saved for future use by pressing F9 to save it to disk. It can be loaded back later by pressing F10. Pressing F5 will fill the screen with copies of that area. Pressing BACKSPACE will fill the whole map with copies of the first block, useful for clearing the screen if the block is a blank space.

Once you have defined your map then you can see it by moving the mouse around. Once you are happy then press space to go back to the main menu and you can save it. There are two save options, one will save the map as world data and the other as landscape data. Note that you now have two files.

WBLOCKS.MBK………..the converted sprites we did before.

WDATA.MBK…………..the data you saved as world data.

You can now put this map into a routine.

10 key off : hide :curs off : mode 0
20 load “WBLOCKS.MBK”,5 : load “WDATA.MBK”,6
30 a=palt(start(5))
40 X=0 : Y=0
50 repeat
60 if jleft then X=X-4
70 if jright then X=X+4
80 if jup then Y=Y-4
90 if jdown then Y=Y+4
100 world logic,start(5),start(6),X,Y,0
110 until X>1200 or X<16

Note there is a resize option which allows you to place bigger sprites on screen but you’re best off keeping them 16×16 as they fit perfectly on screen.

Well that’s it for this article. The best way to learn more about EDDY is to play around with it. Before I go I’ll just say that the above scrolls a world map. Try converting your sprites to landscape blocks and loading them into the routine instead of the world blocks. Remember that these maps only scroll up and down.

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Dean Sharples

3 CommentsLeave a comment

  • Little know fact about Eddy, when you copy and paste a block, it doesn’t check that it is overlapping the bottom so if you copy a big block and paste it near the bottom of the map, you run the risk of over-righting memory and crashing STOS entirely.

  • Hi,
    trying to use EDDY on a ST emulator (Hatari).
    When I press space (to enter menu) the program freezes.
    Any ideas what I am doing wrong please?

    Phil

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