Atari 520STE Field Service Manual page 44

I3 RAM addressing. Wrong location is being addressed.
I4 MMU error. No DTACK after RAM access.
I5 RAM Sizing Error. Uppermost address fails.
I6 Bus Error Handling Failed. Bus Error occurred (on purpose), but caused a
crash (e.g. System was unable to read the vector from RAM).
I7 Bus Error not detected. Glue not asserting Bus Error or the signal is not
reaching the CPU.
3.21.2 Exception (may occur at any time.)
E1 Not used
E2 Not used
E3 Not used
E4 Not used
E5 Not used
E6 Autovector Error. IPL0 is grounded or 68000 is bad.
E7 Spurious Interrupt. Bus error during exception processing. Device interrupted,
but did not provide interrupt vector.
E8 Internal Exception (generated by 68000).
E9 Bad Instruction Fetch.
EA Address Error. Tried to read an instruction from an odd address or read or
write word or long word at an odd address. Usually this error is preceded by a
bus error or bad instruction fetch.
EB Bus Error. Generated internally by the 68000 or externally by GSTMCU.
Usually caused by device not responding. Displays the address of the device
being accessed.
3.21.3 RAM
R0 Error in low memory, possibly affecting program execution. R 1 Error in RAM
chip.
R2 Address Error. Bad RAM chip or Memory Controller. Address line not working.
R3 Address error at 64K boundary.
R4 Error during video RAM test. Bad RAM chip.
3.21.4 Keyboard
K0 Stuck key.
K1 Keyboard controller is not responding.
K2 Keyboard controller reports error
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