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Author Topic: My Amiga Dream is Dead!  (Read 4091 times)

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Offline Castellen

Re: My Amiga Dream is Dead!
« on: January 18, 2017, 06:29:03 PM »
Quote from: Banstyx5;819997
Last piece I needed was a 1200 board , and I found one.



There a lot of questions from there.  Do you know if the board worked to begin with?  Are the ROMs in correctly?  Because they're socketed, it's often something that gets abused.  e.g. odd/even ROM swapped, aligned at the top of the 42 way socket instead of the bottom, or put in backwards (which usually causes permanent ROM damage).

If nothing at all is connected to the board except monitor and power input, it should power up to the insert disk screen after about 30 seconds.




Quote from: utri007;819998

## Red - An error in the Kickstart rom as detected.
## Green - An error in the Chip Ram was detected.
## Blue - An error in the custom chip set was detected.
## Yellow - The CPU encountered an error before the system's error-trapping code (the code the calls up the Guru) was in place.
## Black - No CPU detected.
## Grey - CPU Passed the test.
## White - CPU failure.



Oh, that old list is doing the rounds again.  I've lost count of the times people have asked to have their CPU replaced because there's a black screen.  Red and Yellow are mostly correct but to explain more:

Red = The ROMs are working to the point where the CPU is running the ROM checksum test (one of the first things to happen at power on), but the ROM checksum failed.

Green = The exception vector setup or the chip memory test failed, basically means that the write + read-back test failed, which can mean bad memory, or something unrelated that's causing the memory not to be accessed correctly.

Blue = I don't think OS3.x does this, might have existed in OS1.x.

Black = Anything can be stopping the boot process (e.g. ROMs inserted incorrectly, some hardware fault), or the boot process failed early on.  Despite popular belief, it's rarely a problem with the CPU itself.

Grey = The early boot stuff completed (memory tests, hardware setup).

White = Usually the result of a hardware timer failure, so can be a CIA fault, missing timing signal (VSYNC, HSYNC, TIC).