Atari 2600 Field Service Manual

GRAY BAR TEST
Purpose:
from the
Format:
position.
black at
To test the function of ?he luminescence lines (LLIO, LW, LV2)
TIA chip to the RF Module.
Move the Color/Black
& White switch to the Black and 'White
There should be eight horizontal gray bars displayed, going from
the top to white at the bottom in even gradations (See Figure
3-9).
The screen should be steady and unchanging. fhese lines may have minor
litches on their edges.
A thin white line always appears just over the top
black)
bar. No color should appear anywhere on the screen. The areas
S
above the top (black) bar and below the bottom (white) bar are of no
importance
to the test. This test should be left on for at least ten seconds
to ensure that there is no "flashing"
of any color or shifting of the gray
bars.
Figure 3-9. Gray Bars Screen
2600/2600A Domestic VCS

Atari 2600 Specifications

General

Manufacturer	Atari, Inc.
Release Date	September 11, 1977
CPU	MOS Technology 6507
CPU Speed	1.19 MHz
RAM	128 bytes
Graphics	Television Interface Adaptor (TIA)
Media	ROM cartridge
Successor	Atari 5200
Colors	128
Sound	2 channels
ROM	4 KB
Controller Input	Joystick