Amiga boot error code colours
From Classicamiga
When the Amiga boots, if it encounters a hardware fault the system will display a solid single coloured screen, or a series of these screens if more than one error is detected.
The following colours are valid for all versions of AmigaDOS since Kickstart 1.3. However, there were several more colours in 1.3 compared to anything included after Kickstart 2.0 was released. However all of the colours listed below are the same for all versions of Amiga kickstart.
- 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.
In addition to colour screen error codes, Guru Meditation error screens are also a common error screen encountered when an Amiga encounters a problem. These and the meaning behind their error codes will be covered soon.
System tests performed during the Amiga's boot test sequence
The following is based on an AGA based A1200/A4000 Amiga. This is different for older OCS based systems.
The system performs the following test sequence:
1. Delays beginning the tests a fraction of a second to allow the hardware to stabilize. 2. Jumps to ROM code in diagnostic card (if found) 3. Disables and clears all DMA and interrupts. 4. Turns on the screen. 5. Checks the general hardware configuration.
If the screen remains a light gray colors and the tests continue, the hardware is OK.
If an error occurs, the system halts. 6. Performs checksum test on ROMs.
If the system fails the ROM test, the screen display turns red and the system halts.
Keyboard Blink Codes
When the Amiga is first switched on the keyboard might blink a number of times to indicate one of the following errors.
- One Blink = ROM Checksum failure
- Two Blinks = RAM test failed
- Three Blinks = Watchdog timer failed
- Four Blinks = A short exists between two row lines or one of the seven special keys (not implemented)
References
[Newtek](2008) - Article [Amiga System Startup Colors]; Website.