HP 9020 Service Manual page 231

Motherboard Pinout Data
D-5
Signal Definition
NICI I/O bus interface control bit 1 (negative true).
NIC2 I/O bus interface control bit 2 (negative true).
NIC3 I/O bus interface control bit 3 (negative true).
NIC4 I/O bus interface control bit 4 (negative true).
NIDO
110
cage door open (negative true). OR'd with NFDO.
NIFC
110
bus interface clear (negative true).
NIODO
110
bus input/output data bit 0 (negative true).
NIODI
110
bus input/output data bit 1 (negative true).
NIOD2
110
bus input/output data bit 2 (negative true).
NIOD3
110
bus input/output data bit 3 (negative true).
NIOD4
110
bus input/output data bit 4 (negative true).
NIOD5 I/O bus input/output data bit 5 (negative true).
NIOD6
110
bus input/output data bit 6 (negative true).
NIOD7 I/O bus input/output data bit 7 (negative true).
NIOD8
110
bus input/output data bit 8 (negative true).
NIOD9
110
bus input/output data bit 9 (negative true).
NIODI0
I/O bus input/output data bit 10 (negative true).
NIODll I/O bus input/output data bit 11 (negative true).
NIOD12
110
bus input/output data bit 12 (negative true).
NIOD13
110
bus input/output data bit 13 (negative true).
NIOD14 I/O bus input/output data bit 14 (negative true).
NIOD15 I/O bus input/output data bit 15 (negative true).
NIOSB
I/O bus data transfer strobe (negative true).
NMI Non-maskable interrupt.
NPAO I/O bus peripheral address bit 0 (negative true).
NPAI I/O bus peripheral address bit 1 (negative true).
NPA2 I/O bus peripheral address bit 2 (negative true).
NPFW Power fail warning (negative true).
NPI Not pop in (negative true). Resets the stack.
NPKPWR Shut down command indicator due to peak power (negative true).
NPOLL I/O bus interface poll (negative true).
NPSTLED
Power supply overtemperature (negative true).
NPV Not power valid; all outputs in spec (negative true).
NSELFTEST Leading edge causes power supply to send stack into self-test via NSYSPU and NPI
(negative true). Originates on keyboard.
NSTLED Stack overtemperature (negative true).
NSTS
I/O bus status (negative true). Driven by keyboard.
NSYSPU Not system pop unsynchronized (negative true). Used with NPI to cause stack to
perform a self-test.
NWAIT
110
bus lengthen IOSB (negative true).
PFLG Printer's flag line; driven by keyboard.
PPON Primary power on; all outputs in spec.
PSDGND Power supply ground for 25 KHz and fan circuitry.
PST Power supply temperature indicator; connected to FANCTL.
PSTS Printer's status line.
PWMEN Pulse width modulator enable.
READ
110
bus data direction (positive true; high indicates data to lOP).