EFIL (part 1)

by Per Nordqvist and Svend Jacobsen



It's a bit of a spooky one, this. Not only has it been written by Per

Nordqvist and Svend Jacobsen (who, in case you're becoming convinced

that I make all these names up, actually come from Sweden), but it's

also a sort of psychedelic, 'hippy' type of program. (Yeah? Andy) The

other thing about it is that it's apocalyptically long, so I've

decided to spice things up by doing it as a cliff-hanging

'two-parter'. So this month you've got the first chunk of the Basic

section, the rest of which will be printed next month along with a

brief hex section and some detailed instructions.



So what's it all about, then? Well, remember last month's Life

program? You do? Well this is roughly the same sort of idea, but a lot

more complicated and interesting to look at. (The more astute among

you will already have realised that Efil is Life spelt backwards.) For

a start Efil is in colour, and that's where things start to get

complicated. Although Efil uses Life's method of generating new cells

by looking at the cells surrounding them, the calculations it does are

a lot more complicated. And you actually get some say in the matter

too.



What the program does when it's generating a new cell is to look at

some of the squares surrounding it (you decide which ones) and then

add up all their colours (with 0 for black through to 7 for white). It

then looks up the answer in a table of rules (which are also specified

by you) and finds the colour of the new cell. This is done for every

cell on the screen, luckily using machine code so it's super- fast.



Other features of the program include adjustable screen-update speed,

from really slow to migraine-inducingly fast, a cell-designing

section, a screen designer, something about 'border colours' which I

haven't quite sussed out yet and a series of built-in demos to give

you a better idea of what's going on.



So make a start of the listing, then, and try to control your

excitement until next month. It'll be worth the wait, I can assure

you.



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EFIL (part 2)

by Per Nordqvist and Svend Jacobsen



Last month I gave you the first bit, and now here's the second bit of

Per and Svend's indecently long but enormously enjoyable Efil. To

recap, it's a sort of hybrid Life program which works in full colour

and has loads of options you can tweak. But you know that already.

What you need to know now is how to get it running and what to do once

it is.



Well, the first part's easy enough - just follow the usual tried and

tested Pitstop routine. Type in the whole of the Basic section

(including last month's bit) and save it onto a tape. Then fish out a

copy of the Hexloader from a previous YS and use it to type in the

hex. Save that after the Basic, reload the whole thing and away you go.



Once it's loaded you'll be presented with a complicated and slightly

baffling menu screen. Fear not. Look more closely and you'll see that

it can be split up into the following sections ...



Affectors: Each cell on the screen is surrounded by eight others, and

here's where you tell the program which of these cells affects the

cell in the middle. Use Symbol Shift together with keys 1-8 to toggle

the affectors on and off, C to reset all affectors, F to set them all,

R to restore them and Space to exit this section.



Rules: Lots of numbers, or possibly only a few, depending on how many

affectors you've set. When the values of the affectors surrounding

each cell are added up a number is produced. Here's where that number

is looked up in order to produce the colour of the cell. Use keys Q,

Z, I and P to move around the list, 8 to move to the start, 0-7 to

select a colour, C to set the whole list to the selected colour, R to

restore the list and Space to exit the section.



Edit: Here you can edit the screen directly to set up a starting

pattern of some sort. Use Q, Z, I and P to move around the screen, 0-7

to select a colour, M to set a cell to the current colour, C to set

the whole screen to the current colour, R to restore the screen and

Space to exit.



Graphics: This is where you can edit the shape of the cells to make

them look a bit nicer (if you want to). Use Q, Z, I and P to move

around the grid, M to toggle a square on and off, C to clear the grid,

F to fill it up, R to restore it, 1 to select a normal cell and 2 to

select a chequered one. Space exits.



Colours: I still haven't worked out what they're on about here but,

assuming you do, here are the keys you'll need - Symbol Shift plus 1-8

selects an affector, 0-7 to select a colour, C to set all to the

current colour, R to restore and Space to exit.



Tempo: This sets the screen update rate, from 255 (agonisingly slow)

to 1 (unfeasibly fast); 0 single-steps. You'll need to type three

digits each time, so for speed 6 type 006, etc.



Demos: A handy section this, as it lets you choose from 10 pre-defined

demo set-ups [Select 0-9. JimG]. Should give you a better idea of what's

going on than any of the above waffle.



Start: This sets the ball rolling, as it were, so sit back and enjoy

the show. And press Enter to single-step or Space to exit.