Ricoh A250 Service Manual page 446

2.6.4 EXFUNC BOARD
EXFUNC BOARD
The EXFUNC board allows JBIG compression and some additional features
become available. In addition, this board expands the SRAM capacity.
QM Coder
• 2 QM coders for JBIG compression.
PAL (PALCE16V8H-15PC)
• 2 PALs make a strobe control signal. This is used for DMA selection.
SRAM
• 512KB SRAM for telephone numbers and other user parameters.
Lithium battery
• Backs up the SRAM.
Switches
Item
SW1 Switches the backup battery on/off
SM
S R A M Q M - C O D E R _ 1
D M A B U S
P A L _ 1
P A L _ 2
Description
2-25
PCBS
Q M - C O D E R _ 2
A891D522.WMF
A250