Tandy Color Computer 3 TRS-80 User Manual

TECHNICIAN SERIES
DIAGNOSTIC SERIES
------------- TANDY COMPUTER PRODUCTS -------------
- CPUSPEED/BAS -
CPUSPEED is a Basic program which allows the technician to see if the cpu
clock is changing speed properly.
To execute this diagnostic: type RUN "CPUSPEED/BAS" and press <ENTER>.
The test should then appear on the screen.
The test should begin by filling the screen with characters, followed by the
message "Press Any Key To Change Speed". The CPU speed (SLOW/FAST) is
display.ed at the top of the screen. By pressing a key to toggle between the
two speeds, there should be an observable difference in speed.
Press <Q> to exit this test.
- PSUEDO/BAS -
PSUEDO is a Basic program which allows checking of the artifacting circuitry
of the color computer. This circuity produces "false" colors when under
the highest color computer-2 graphics mode. Normally, this graphics mode
would produce only two colors (white and black or green and black), but
by drawing the pixels close together, the artifacting circuitry will send out
a color burst signal to simulate colors ("false" colors). Using this test
allows the technican to determine whether or not the artifacting circuitry
is working. This test is only valid on composite monitors, since "false"
colors are not produced on the RGB monitors.
To execute this diagnostic: type RUN "PSUEDO/BAS" and press <ENTER>.
The test should then appear on the screen.
Press any key to begin the test. Four rectangles will be drawn on the
screen. The first (top) rectangle appears with a black center while the
fourth (bottom) rectangle appears all white. The second and third rectangles
will appear to have color on a composite monitor.
Press the <Q> key to exit this test and exit to Basic.
COLOR COMPUTER-3 DIAGNOSTICS
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Tandy Color Computer 3 TRS-80 Specifications

General

Brand	Tandy
Model	Color Computer 3 TRS-80
Category	Desktop
Language	English