Zct; System Control Panel - Xerox 550 Reference Manual

SET LOW CLOCK MARGINS
This command causes the system clock frequency to be set
to low margin. The CLOCK MARGIN indicator (see System
Control Panel) is illuminated.
If
high and low clock margins
are both set, an undefined intermediate frequency results.
The system clock is restored to a normal frequency by either
a SUPER RESET, Z
C
MM4, or a CLEAR MM FEATURES,
ZCMMO, command. The system clock also assumes the nor-
mal level following power on.
Z\wa
SET HIGH CLOCK MARGINS
This command causes the system clock frequency to be set
to high margin. The CLOCK MARGIN indicator (see Sys-
tem Control Panel) is illuminated.
If
high and low clock
margins are both set, an undefined intermediate frequency
results.
The system clock is restored to a normal level by either a
CLEAR MM FEATURES, ZC MMO, commqnd or a SUPER RESET,
ZCMM4, command. The system clock also assumes the nor-
mal level following power on.
zct.1M9
SET MEMORY INTERLEAVE OVERRIDE
This command inhibits interleaving all memory units and
is used primarily when running certain memory diagnostic
programs. It is allowed only when the system is in the
maintenance mode. The change in the manner in which
memory is accessed when interleaving is inhibited versus
when interleaving is permitted requires that programs be
reloaded each ·time the interleave control is changed.
Note that the SET MEMORY INTERLEAVE OVERRIDE
command inhibits interleaving all memory units, whereas
the INTERLEAVE switches of the Configuration Control
Panel (described in Chapter 6) inhibit interleaving on an
individual memory unit basis. The INTERLEAVE DISABLE
indicator on the SCP is illuminated while INTERLEAVE
OVERRIDE is in effect.
The SET MEMORY INTERLEAVE OVERRIDE command re-
mains in effect (interleaving is inhibited) until either a
CLEAR MM FEATURES, ZCMMO, ora SUPER RESET, ZCMM4,
command is executed. Interleaving is automatically en-
abled following a power on/off cycle.
Z~MA
SET/CLEAR DISPLAY INHIBIT MODE
This command may be used either to SET DISPLAY INHIBIT
MODE or to CLEAR DISPLAY INHIBIT MODE. When the
Display Inhibit Mode is set, all data output associated
with
~he Sys~em COiitro~ COi1so~e
(Seq
function ;s ;n-
hibited; however, data output generated by the software
is not affected.
The Display Inhibit Mode is normally set to inhibit print-
out during execution of SCC functions which do not require
a display.
144 Control Commands
The Display Inhibit Mode may be cleared by a CLEAR
DISPLAY INHIBIT MODE, ZCMMA, a CLEAR MM FEA-
TURES, Zc MMO , or a SUPER RESET, Z
C
MM4, command.
The Display Inhibit Mode is automatically cleared follow-
ing power on.
LOAD SPECIAL
The LOAD SPECIAL command is accepted only
if
the
system is in the IDLE state. The LOAD SPECIAL command
is used in situations where all of the functions performed
by the LOAD NORMAL command are not desired (e. g.,
in loading a postmortem dump sequence). The LOAD
SPECIAL command causes only the bootstrap loader program
to be written into memory without diagnostics or memory
clearing prior to the load. A II10ad device address II, spec-
ified by the hexadecimal digits 11#11##
II
in the command, is .
stored in Q register
Xll E'.
When using the LOAD SPECIAL
command, the operator must also enter the SYSTEM RESET
and SYSTEM RUN commands before loading will commence.
Zct.OT
MEMORY SET
This command causes all memory to be set to the value con-
tained in the BP internal register Q26(X
I
1A
I
) .
The com-
mand may be entered only when the system is in the
IDLE state.
ZCT
SET/CLEAR TRANSPARENT TEXT MODE
This command is used either to SET TRANSPARENT TEXT
MODE or to CLEAR TRANSPARENT TEXT MODE. When
the
Transpare~t
Text Mode is set, software-driven I/O
from the System Control Console is inhibited, but all
SCC FUNCTIONS are processed in the normal manner.
This feature permits the operator to make marginal notes on
the console printout for logging purposes.
If
two different
control consoles are connected in parallel
(i.
e., remote
device is connected as a System Control Console), the
Transparent Text
~.;\ode
peimits messages to be exchanged
between the two devices.
If
the SCC FUNCTIONS switch
is in the DISABLE position, input data is passed into the I/O
system regard
I
ess of the status of the Transparent Text Mode.
The Transparent Text Mode may also be cleared by a SUPER
RESET, ZC MM4, command.
SYSTEM CONTROL PANEL
The System Controi Panei contains indicators and controis
which are used primarily when maintenance and/or diag-
nostic activities are performed. The computer operator
normally monitors certain indicators (as described below)
to ascertain conditions within the computer system (e. g.,
status of pri mary power, status of sense swi tches, status of
BP, and status of ALARM indicators).