Todo: Order of checks.
Some information by Channelmaniac.
The AES home console only performs checks when no game is detected.
|Error||No game||WORK RAM ERROR||COLOR RAM ERROR||VIDEO RAM ERROR||SYSTEM ROM ERROR||MEMORY CARD ERROR|
|Meaning||All tests passed (AES does not test the Z80). Cartridge not detected.||68k user RAM R/W error||Palette RAM R/W error||VRAM R/W error||System ROM checksum mismatch||Memory card R/W error (only tested if card present and blank)|
Additionnal checks are performed on MVS systems. The SP-S2 system ROM does them in the following order:
- Work RAM
- Backup RAM
- Palette RAM bank 0
- Palette RAM bank 1
- Low VRAM
- High VRAM
- System ROM checksum
|Error||BACKUP RAM ERROR||Calendar freeze||CALENDAR ERROR||Z80 ERROR|
|Meaning||Backup RAM R/W error||RTC isn't giving Time Pulse||RTC ran to slow or too fast||Z80 didn't reply to command|
When a MVS board is powered up without cartridges inserted, the border color around the edges of the crosshatch screen indicates the system ROM region:
- Red: Japanese, SPJ2
- Cyan: USA, SPU2
- Blue: Korean/Spanish, SPS2
- Yellow: European
- Green: 6 slot (ROM name ?)
The Universe BIOS does not use the above color codes to indicate errors.