AT&T PC 6300 - Memory Test

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DIAGNOSTICS
The LSI test checks the functionality of the following integrated
circuits:
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• 8250 Communication Chip
• 8253 Timer
I I • 8237 DMA Controller
• 8259 Interrupt Controller
n * 58174 Real-Time Clock
• 8041 Keyboard Controller
765 Floppy Disk Controller.
The ROM Test is performed by calculating a checksum. The
checksum, defined to be a byte addition of all the bytes in the high
and low ROM modules, is summed and compared to zero.
The speaker test puts out tones of 50,100, 200, 400, 800, 1600, 3200,
and 6400 hertz.
Memory Test
The Memory test performs the following tests consecutively:
Addressing Test
Fixed Pattern Test.
Addressing Test: This test writes into each memory
location its address. The memory is then checked to verify
the addresses. This test is then repeated, writing the
complement of the address into each memory location.
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