A downloadable game

* * * 10 UFO CHASE * * *

Category: PUR80

Platform: C64

Emulator: Vice is fine


NOTE: THE .PRG FILE IS BASIC COMPILED


AIM OF THE GAME

Survive the much long as possible in your run without colliding the 2 enemies


CODE

0d=255:?"{clear}{green}":pO53280,0:pO53281,0:v=53248:pOv+21,d:pO2040,13:pO2041,14:n=75:x=50
1fOt=0to10:fOs=0to30:?"V";:nE:?:nE:fOt=0to59:rEa:pO832+t,a:pO896+t,a:pO960+t,a
2nE:w=d:z=y:j=d:k=70:pO2042,15:c=53270:dEfny(q)=-(q>=0)*(-q*(q<n)-n*(q>=n)):dA0
3dEfnx(x)=(-d*(x<0))-x*(x>=0aNx<=d)*-(x<=d):dA56,0,1,255,0,15,255,224,31,255,240
4fOt=6to0stE-1:pOc,(pE(c)aN248)+t:m=pE(56320):y=y+2*(m=126)-2*(m=125):y=fny(y)
5b=pE(53278):goS9:nE:x=fnx(x+2):w=fnx(w-rN(.)*16):z=fny(z+rN(.)*8+-rN(.)*8)
6j=fnx(j-rN(.)*16):k=fny(k+rN(.)*8+-rN(.)*8):on1+(pE(53278)aN1)gO4:eN:dA55,255
7dA216,59,255,184,125,255,124,126,254,252,127,131,252,255,57,254,255,109,254,255
8dA57,254,127,131,252,126,254,252,125,255,124,59,255,184,55,255,216,31,255,240
9pOv,x:pOv+1,52+y:pOv+2,w:pOv+3,52+z:pOv+4,j:pOv+5,52+k:reT:dA15,255,224,1,255,0


COMMENT

LINE 0:I use the value 255 many times,so better to assign it to a variable.So d=255. Follows some sprites pokes and other inits.

LINE 1:the 2 for cycles are here to print the grid. The other for cycle reads data in order to make the shapes of the 3 sprites involved in the game, the UFOs starships.

LINE 2:variables w,z,x,y,j,k are the x and y of the 3 sprites. Here I define the function  y(q) that is used to make sprites' Y stay in the interval 0-75.

LINE 3:similarly as for Y, I define a function to make X stay into an interval, the x(x) function. Basically it makes X to stay into 0-255. If x<0 then x becomes 255, and if x>255 it becomes 0. It manages the player's UFO (going towards the right direction) and the opponents (going opposite direction)

LINE 4:main cycle here. The for is used to change the x register hardware scroll in order to have a "smooth" horizontal scrolling. Then I catch the joystick movement into variable m, and, accorgin to its value, I move the player up or down using the y(q) function. 

LINE 5:the first peek of 53278 is to reset the collision register.The gosub 9 updates sprutes positions.The following calls to fnx() update sprites X positions, moving randomly the enemies on X assis.

LINE 6:Random y for enemies with calls to fny(), then collision check and ending of the game in positive case ,using the ON .. construct

LINE 7 and 8: datas for sprites.

LINE 9 as said, updates sprites positions

StatusReleased
Rating
Rated 4.0 out of 5 stars
(1 total ratings)
AuthorBASIC 10Liner
GenreAction
Tags10liner, 8-Bit, basic, Commodore 64

Download

Download
+10ufochase.prg 5 kB
Download
10ufochase.txt 2.4 kB
Download
10ufochase.d64 170 kB

Development log

Comments

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Greetings Arturo,

we hope you are doing great. I am Areeba (aka Titania) from the BrewOtaku-Team, we are launching BrewOtaku #002 - The Homebrew Gaming Magazine soon.

We loved your work and we have mentioned "10 UFO Chase” in it. Kindly share your contact details so we can share it with you. You are anyhow free to share this on your social media channels or homepage.

We look forward to hearing from you soon.

Kind regards

Titania