Zenith H-100 Service Manual page 59

RESET Reset signal.
SIDE 1 Otherwi se known as side select output. When high
side
1
is selected in the drive. When low, side
o
is selected.
sINP Status signal signifying data input to the bus
(read cycle) may occur.
sOUT Status signal signifying data output from the
bus (write cycle) may occur.
STEP Steps the drive head one step per pulse. _
STS Strobe output from the
1691
(U
1)
phase lock loop
control.
TG43 Track greater than 43. The drive read/write head
is over or past track 43 (track of mandatory
precompensation in double density 8" drive.
TK~
Track O. The drive read/write head is over track
o
on the diskette.
TWOSIOEO
The 8" drive is set for two-sided operation with
a two-sided diskette.
VFOE/WF VFO enable/write fault. When WG is asserted,
VFOE/WF flags write faults when deasserted,
terminating any write commands. When WG is
deasserted, VFOE/WF enables the data separator
in the 1691.
Vl¢*-V11*
Vector interrupts.
5-143
10-82
WAIT
WAITEN
WO
WOIN
RDY line is low (not ready).
Wait enable. Set ROY line low on all accesses
of the
1191
data register.
Write data. Contains the data to be written onto
the diskettes as well as the clock signals.
Write data into the
1691
phase lock loop control.