Kurzweil K2000 Service Manual page 65

SECTION 4
DIAGSO_I.OOC 12/22/92
To optimize the processing speed, the K2000 performs a one-time software
operation when powered up for the first time. The memory management unit
(MMU) in the gate array logic chip (GAL) located at U35 on the engine board
executes a "swap bit" function which makes Block 0 of the CPU responsible for
the PSRAM, and Block 1 responsible for the Boot EPROM and setup EPROM.
Consequently the PSRAM functions are processed as early as possible.
The Swap Bit Test checks to make sure that the swap bit function has taken
place. The swap bit function also involves the GALs at U10 and U11. If the
test fails, check the traces between U10, U11, and U35. If they appear
intact, one or more of the GALs may be defective.
4.14.12 Calvin and Hobbes Tests
IMPORTANT: The Calvin and Hobbes tests-especially tests 6 and
~are
not 100%
reliable in Version 0.4. A Failure of any test may not necessarily indicate
a component failure. If a failure message occurs, run the Calvin and Hobbes
tests three or four more times, and compare the results. If any of the
subsequent tests pass, the component in question is probably good. If the
tests fail repeatedly, the component in question is probably-but not
necessarily-bad. If failures occur with any of the Calvin and Hobbes tests,
it is recommended the unit be upgraded to Version 1.2 Engine software, which
includes Version 1.0 of the diagnostic software. The Calvin and Hobbes tests
in Version 1.0 are reliable.
The 13-step Calvin and Hobbes memory test checks the connections between the
CPU and the three VLSI sound engine chips: Calvin, Hobbes 0, and Hobbes 1.
Calvin handles sample fetching tasks, and Hobbes 0 and 1 primarily perform
wave form generation and DSP functions.
Calvin and Hobbes have undergone rigorous testing prior to mass manufacturing,
and are extremely unlikely to be defective. If one or more of the steps in
this test indicate a failure, the problem is probably to be found in the
connections between the chips and the CPU. The test results are displayed as
shown in Figure 6. The significance of failures in each step of the test is
explained below. Steps 2.1-2.3 test the connections to the internal RAM and
internal registers of Calvin and Hobbes.
When analyzing the results of these tests, the result should be a PASS message
for each test. The hexadecimal numbers that appear on the display are
irrelevant as long as they match for each test. The numbers shown in figure
5.6 are arbitrary, and may differ from the numbers seen in the unit under
test. This does not indicate a problem.
If any of the tests fail, check the connections between the components in
question, as described in the paragraphs below. If test #2 fails, check all
the connections between the CPU, Calvin, Hobbes 0, and Hobbes 1. Note that
expected observed values are not given on the line indicating the status of
test #2. Instead, a PASS or FAIL message will be seen for each of the three
steps in test #2.
NOTE: The Calvin and Hobbes tests are interrelated, and are sequenced from
the least significant test to the most significant. If anyone test fails,
the subsequent tests are likely to fail as well. In this case, start by
checking the components related to the first test that failed. If a
malfunction occurs, repair the malfunction and run the Calvin and Hobbes test
again. It is likely this will result in the subsequent tests will passing
when retested.
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