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|'''Error''' |[[WORK RAM ERROR]] ...

*"WARNING BANK ERROR": [[Cartridge self-checking]]. Cartridge edge dirty, bad 74LS74 for [[banks *"WARNING COPYRIGHT MESSAGE": [[Slot check security]]. Clear backup RAM. Bad [[uPD4990]]. Bad [[system ROM]]. ...

...placed. Multiple RAM chips may have been killed by a "long" voltage spike. RAM chips also tend to die one after the other on cabs which have their PSU's v ==Backup/Work/Video RAM error== ...

* Checks the 64KiB of work RAM by filling with $5555 and reading back, filling with $AAAA and reading back * If all dipswitches are down, check backup RAM like before but in an infinite loop ...

The [[system ROM]] doesn't give a [[CALENDAR ERROR]] in this particular case because of a programming oversight. * Try to reset Backup RAM content: ...

* Try to reset Backup RAM content: * You can use unibios to skip this error ...

...s out it is being run for the first time on the system (thanks to [[backup RAM]] data), it forces a [[watchdog]] reset. If the system doesn't reset itself *The calendar data zone in the [[BIOS RAM locations|BIOS RAM]] is cleared, then [[READ_CALENDAR]] is called. If {{BR|BIOS_MONTH}} is gre ...

* COIN: 3rd pin is the coin switch, active low, pull high. Causes an error before attract mode if left floating. * PRT1: Printer remote also (needed or just for backup ?). The BUSY line can be tied with the 2 other ones ? ...

...prone to data loss if the voltage drops below 2V. Unlike the MVS [[backup RAM]] battery, the memory card one isn't rechargeable. ...over the other one. If both checksums are bad, the system ROM displays an error. ...