Croma24 Service Manual
The system firmware is stored in Flash EEPROM and can be up- graded by opening the Control Panel located on the host computer. Once the Control Panel has been executed, it first starts an initial- ization and status communication sequence with the printer. The Control Panel requires ink levels and deadband information to load correctly. At the same time, it checks the version of firmware that is loaded on the printer.
The flash EEPROM is a volitile memory in that it will lose updated information after a loss of power and revert back to the firmware that was initially installed at the factory. If the Control Panel contains a newer version of the firmware than the printer is cur- rently loaded with, it automatically updates the firmware at the startup of the Control Panel.
DRAM
DRAM is Dynamic Random Access Memory which provides tempo- rary storage of the microprocessor calculation and input/output data. It is also a faster type of memory then the Flash EEPROM. Thats why the printer control program is also copied from the Flash EEPROM to RAM, where it can be executed faster.
The printer is supplied with 2 Megabytes of DRAM permanently installed on the Main PC Board. Memory expansion is not available for this printer. Since it only supports
Serial EEPROM
Serial EEPROM is an Electrically Erasable, Programmable, Read Only Memory which provides storage for calibration constants and user configuration data entered from the host computer.
A 1K bit serial nonvolatile EEPROM stores calibration and configu- ration information. It retains data while the unit is off.
32 | Theory of Operation |
