2. ROM
• 512 kB (4 Mbit) EP-ROM for system software storage
3. DRAM
• Backed up by the dry cells on the FCU (Only used in the China model)
4. SRAM
• 32 kB SRAM for system and user parameter storage
• Backed up by the lithium battery on the FCU
5. Video SRAM
• 8 kB SRAM for video processing
6. Oscillators
• 29.952 MHz oscillator for system clock generation
• 32.768 MHz oscillator for the real time clock. This is backed up by the
lithum battery on the FCU
7. Others
• Stepper motor driver
• Battery back up circuit for back up when the power is turned off
• DC/DC converter which generates +5V
• Cutter motor driver
• Thermal head control
• Telephone answering feature (Only used in the China model)
2.3.2. PSU
• +24Vdc generation
• Overcurrent protection circuit
• Surge protection circuit
DETAILED SECTION DESCRIPTIONS August 7th, 1995
PCBs
2-13