Casio UP-250 Technical Manual page 26

Interface Connector Pin Assignments
IEEE 1284 interface connector pin assignments and functions
Pin number
1 Host
2 Host/Ptr
3 Host/Ptr
4 Host/Ptr
5 Host/Ptr
6 Host/Ptr
7 Host/Ptr
8 Host/Ptr
9 Host/Ptr
10 Printer
11 Printer
12 Printer
13 Printer
14 Hostr
15
16
17
18 Printer
19-30
31 Host
32 Printer
33
34 Printer
35 Printer
36 Host
NOTES:
Overscored signal names are LOW active signals.
If a host does not provide for the signal lines listed above, two-way communication fails.
For interfacing, signal lines must use twisted pair cables with the return sides connected to signal
ground level.
Interfacing conditions must all be based on the TTL level to meet the characteristics described below.
In addition, both the rise and fall time of each signal must be 0.5 µs or less.
Data transmission must not ignore the ACK or BUSY signal. An attempt to transmit data with either
the ACK or BUSY signal ignored can cause lost data. (Data transmissions to the printer must be made
after verifying the ACK signal or while the BUSY signal is at a LOW level.)
Interface cables should be as short in length as possible.
NC: Not Connected
ND: Not Defined
Source Compatibility Mode
Strobe
Data0 (LSB)
Data1
Data2
Data3
Data4
Data5
Data6
Data7 (MSB)
Ack
Busy
PError
Select
AutoFd
NC
GND
FG
Logic-H
GND
Init
Fault
GND
DK_STATUS
+5V
SelectIn
Nibble Mode
Host Clk
Data0 (LSB)
Data1
Data2
Data3
Data4
Data5
Data6
Data7 (MSB)
PtrClk
PtrBusy/Data3,7
AckDataReq/
Data2,6
Xflag/Data1,5
HostBusy
ND
GND
FG
Logic-H
GND
Init
DataAvail /Data0, 4
ND
ND
ND
1284-Active
— 17 —
Byte Mode
Host Clk
Data0 (LSB)
Data1
Data2
Data3
Data4
Data5
Data6
Data7 (MSB)
PtrClk
PtrBusy
AckDataReq
Xflag
HostBusy
ND
GND
FG
Logic-H
GND
Init
DataAvail
ND
ND
ND
1284-Active