Atari 400 Basic Reference Manual

Using the note values in Table 10-1, the following example demonstrates how to
write a program that will "play" the C scale.
TABLE 10.1. TABLE OF PITCH VALUES FOR THE MUSICAL
NOTES
HIGH
NOTES
MIDDLE C
LOW NOTES
10 F.:EAD A
~
c
B
A# orB~
A
G# or A~
G
F# or G~
F
E
D#
orE
D
C#
or D~
c
B
A# orB
A
G# or A~
G
F# or G~
F
E
D# orE~
D
C#
or D~
c
B
A# orB~
A
G# or A~
G
F# G~
F
D
D# or I~
D
C#
or Db
c
20 IF A=256 iHEt·i HiD
30 SOUr·iD ~3 .' A .. 1 (1 .• 1 0
40 FOP ~·J=1 TO 400: r·iE>~T ~·J
50 PRWT A
60 GOTO 10
70 END
29
31
33
35
37
40
42
45
47
50
53
57
60
64
68
72
76
81
85
91
96
102
108
114
121
128
136
144
153
162
173
182
193
204
217
230
243
80 DATA ~·9 .. 31.· 35, 4f) .. 45 .. 4 7 .. 53 .. 6(1, 64, 72 ·' :31
191.· 96.: 108.: 121
90 [lATA 12:3.~ 144.~162 .. 1:::2.~ 193.:217)243 .. 256
Figure 10-1. Musical Scale Program
Note that the DATA statement in line 80 ends with a 256, which is outside ofthe
designated range. The 256 is used as an end-of-data marker.
58 Sounds and Game Controllers

Atari 400 Specifications

General

Manufacturer	Atari
Model	400
Type	Home Computer
Release Year	1979
CPU	MOS Technology 6502
CPU Speed	1.79 MHz
ROM	10 KB
Operating System	Atari OS
Keyboard	Membrane keyboard
RAM	8 KB (expandable to 48 KB)
Graphics	ANTIC and GTIA chips
Sound	4 channels
Display	RF output for connection to TV
Storage	Optional cassette tape drive or floppy disk drive
Ports	Cartridge
Display Resolution	320x192 (16 colors)