Atari SUPER SPRINT - Ram;Interrupt;Rom Test; 6502 Processor Test; Figure 3-1 RAM Test Fails; Figure 3-2 Interrupt Test Fails

Self-Test Super Sprint
RAM/Interrupt/ROM Test
The RAM/Interrupt/ROM Test screens are shown in Fig¬
ures 3-1, 3-2, and 3-3. These screens display the failure
information for the RAM, interrupt, and program ROM
circuitry on the CPU and Video PCBs. If the RAM/Inter¬
rupt/ROM test passes, the display advances to the 6502
Processor Test.
The RAM test checks the condition of the T-l 1 micropro¬
cessor RAM, zero page RAM, motion object RAM, play-
field RAM, alphanumeric RAM, and associated circuitry
located on the Video PCB. If the RAM test fails, an error
message gives the location of the failed RAM or associated
circuitry on the Video PCB as shown in Figure 3-1 ■
If the zero-page RAM or associated circuitry fails, the
screen turns red and the address location of the failed
component flashes continuously to facilitate
troubleshooting.
After the RAM test passes, the interrupts on the CPU and
Video PCB are checked. If the interrupt test fails, an error
Figure 3-1 RAM Test Fails
Figure 3-2 Interrupt Test Fails
message as shown in Figure 3-2 can appear on a green
screen, which indicates a possible vertical-blanking or in¬
terrupt-logic failure.
After the interrupt test passes, all eight of the program
ROMs on the CPU PCB are tested for checksums. If the
ROM test fails, an error message gives the location of the
failed ROM or associated circuitry as shown in Figure
3-3.
To exit from the RAM/Interrupt/ROM Test and obtain the
Switch Test screen, press and hold down the red start but¬
ton for about a second, and then release.
6502 Processor Test
The 6502 Processor Test screen provides visual and au¬
dible information to indicate the condition of the 6502
sound microprocessor and associated circuitry. All func¬
tions of the sound microprocessor are checked including:
RAM/ROM, interrupts, music synthesizer, and sound-ef¬
fects processor. Basic communication between the T-l 1
(master) and the 6502 (slave) microprocessors is also
checked.
The 6502 test starts with a reset/communications check
that first resets the 6502 and then checks for proper re¬
sponse to start up protocol. This test checks the com¬
munications ports (T-l 1 to 6502 and 6502 to T-l 1), the
6502 reset circuit, and the general condition of the 6502.
If the 6502 circuitry does not respond properly to the
reset, the system retries the reset procedure ten times.
Then an error message and retry count number is dis¬
played as shown in Figure 3-4.
If the 6 502 circuitry fails to reset through all ten attempts,
a communications error message is displayed as shown in
Figure 3-5.
If the reset/communications check passes, then the con¬
dition of the 6502 microprocessor, RAM, ROM, inter¬
rupts, music (Yamaha) synthesizer, and associated cir-
3-2