System Control Section; Reading Of Keys; Reading Of Function Switches - Sony UP-895 Service Manual

4-4. System Control Section

The system control section mainly consists of a microcomputer (IC304) and performs the following
processing.

4-4-1. Reading of Keys

IC304 monitors the PRINT, OPEN/CLOSE, COPY, FEED, and REMOTE keys on the door panel. Each
key is activated when the falling edge of a signal is detected.
IC304 Signal name
73pin nDOOR_KEY
74pin nPRINT_KEY
75pin nCOPY_KEY
76pin nFEED_KEY

4-4-2. Reading of Function Switches

IC304 monitors the setting of a front slide switch, inner slide switches, and a rear DIP switch and reflects
its setting on the operation.
Front slide switch (on the front panel)
IC304 Function
80pin POSI/NEGA
1pin STANDERD/SIDE
79pin PRINT SIZE
Inner slide switches (S1 through S4)
IC304 Function
5pin SMOOTH
2pin SHARPNESS
4pin PAPER TYPE
3pin GAMMA
4-8
Operation
L: NEGA
H: POSI
L: STANDARD
H: SIDE
0.00 V: SMALL
1.25 V: NORMAL
2.50 V: ZOOM1
3.75 V: ZOOM2
5.00 V: ZOOM1&2
Operation
L: NORMAL
H: HIGH
0.00 V: NORMAL
2.50 V: SOFT
5.00 V: HARD
0.00 V: TYPE I
1.67 V: TYPE II
3.33 V: TYPE III
5.00 V: TYPE IV
0.00 V: TONE I
2.50 V: TONE II
5.00 V: TONE III
UP-895/(E)