Ncu - Ricoh FAX680MP Service Manual

31 March, 1997
TC35167F FAX ENGINE
1) 8-bit MPU
• Memory management
• DMA control
• Interrupt control
• Serial interface control
• Tx motor control
• Real time clock (battery backed-up)
2) Modem (V.29, V27ter, and V.21)
• Tone/DTMF detection
• Tone/DTMF generation
3) Image Processor
• Shading correction
• Automatic background control
• 32-level halftone (dither)
4) Other
• Compression and decompression
M68000
1) MPU for printer functions
FOX2
1) Printer motor control
2) Print head control
3) Parallel port control
MEMORY
1) ROM
• 128 kB EPROM for fax firmware
• 128 kB EPROM for printer firmware
2) RAM
• 512 kB DRAM for SAF (128 kB), ECM (384 kB) memory
• Optional 1 MB DRAM for SAF extension
• 128 kB DRAM for printer data spooling
• 8 kB SRAM for fax system and user parameter storage (battery backed-
up)

2.4.2 NCU

JUMPER SETTINGS
• Germany - CN6 is "Shorted".
• Switzerland - CN6 and CN24 are "Shorted".
• Other European countries - No jumper installed.
2-11
PCBs