Apple LaserWriter Select 310 Printer - Manual (Page 19)

C H A P T E R 1
LaserWriter Select 310 Hardware
Communication Ports 7
Figure 1-4 Timing for a Centronics interface
19-30 SIGNAL
GROUND – Signal ground
31 Not connected – This line is not connected
32 /FAULT O Fault signal; asserted if there is a printer
problem
33-36 Not connected – These lines are not connected
NOTE Inputs and outputs are referenced to the printer. An input (I) signal is
sent from the host computer to the printer, and an output (O) signal is sent from
the printer to the host.
Table 1-3 Signal descriptions for a Centronics parallel port (continued)
Pin
number
Signal name I/O Description
Data
/PSTROBE
PBUSY
/PACK
a. Data setup time before PSTROBE on
b. PSTROBE on pulse width
c. Data hold time after PSTROBE off
d. PSTROBE on to PBUSY on
e. Duration of PBUSY on (printer on line)
f. PBUSY off to /PACK on
g. /PACK on pulse width 0.5µsec
1.0µsec
0.5µsec
0.0µsec
10.0µsec
0.0µsec
1.5µsec 2.5µsec
500µsec
1.0µsec
10.0µsec
Timing specification Min. value Typical value Max. value
a c b
d
f
e
g