Simon (Amstrad CPC) by Copper France

SIMON

This is very simple Simon game for the Amstrad CPC.

Keyboard arrows are used to repeat the sequence of tones and lights.

TECHNICAL PART

The game works on all Amstrad CPC (using only BASIC 1.0)

1) Control Characters

The game use a lot of Control characters to replace MODE, PAPER, CLS, BORDER, INK in only one PRINT in the first line :

MODE is CHR$(4)+"0" FOR MODE 0

PAPER is CHR$(14)+"1" FOR PAPER 1

CLS is CHR$(12)

INK is CHR$(18)+CHR$(16+i)+CHR$(64+v)+CHR$(64+v) for INK i,v,v (16+i to avoid \0 and 64+v to avoid \0 and ")

BORDER is CHR$(29)+CHR$(64+13) for BORDER 13,13 (At the end so last CHR$(13) done by PRINT)

Graphics Or Mode CHR$(23)+CHR$(3) is used to draw color keys behind black circles and background color.

CHR$(30) is used to replace LOCATE 1,1 and CHR$(14) for PEN before printing score

CHR$(31) is used to replace LOCATE before printing high-score

2) Graphics Or Mode

Colors 2,4,6,8 are used for color keys

Color 1 is used for background

Color 15 is used for black discs

With Or Mode color keys (2,4,6,8) become (3,5,7,9) when drawn above background that's why they use same INK as the background

With Or Mode anything drawn above color 15 is not visible (x Or 15 = 15)

3) Listing description

Line 1: Graphics initialization in one PRINT / DEFINT for speed / DATAs for radius of 3 discs

Line 2: ORIGIN in center of screen / Loop for drawing discs / DATAs for color keys (INK value / SOUND period, INKEY value)

Line 3: Radius square / Loop for drawing disc / Graphics Or Mode

Line 4: Loop for drawing keys

Line 5: Loop for drawing X above keys / Array initialization

Line 6: Simon initialization or loose

Line 7: New tone light checking it's different of the previous one / Sequence play

Line 8: Sequence repeat and check

Line 9: Sequence repeat and check / High-score

Line 10 : Sub routine to light up and play a tone

5) Variables

s,t      : Coordonnate for X drawn above keys

i        : Loops

p        : Graphics pen of disc (15 / 0 / 15) / Key number

r        : Radius of disc

a        : Radius square of disc

x        : Loop for abscissa between -r and r

y        : Ordinate / Loop for keys

p()      : Array of keys

d        : Duration of sound

n        : Number of tones in the sequence

m        : High-score

c()      : Array of INK values

s()      : Array of SOUND periods

k()      : Array of INKEY values