Ce Control Panel - IBM 5444 Manual

Chapter 6. Console and Maintenance Facilities
Section 1. Console
OPERATOR CONSOLE
There is no operator console.
CE CONTROL PANEL
• Contains two switches for CE control; the 5444 is
automatically read-selected and write-inhibited.
The CE control panel (Figure 1-63) is mounted on top
of the DC box (see Figure 1-4) and contains two
switches for CE control of carriage movement and head
selection. CE control is effected when the mode-select
switch is set to any position other than ON-LINE;
'readf line to the using system drops. Under CE control,
the machine is automatically write-inhibited: any
read/write head can be selected.
Note: Carriage travel is still restricted by the home
detection logic and the carriage overrun interlock switch,
as for normal on-line operation.
Mode-Select Switch
• Using the mode select switch, the CE can select any
read/write head.
The mode-select switch is a seven-position rotary switch
as follows:
On-line Position
The 5444 is functionally connected to the using system;
the CE controls are inoperative.
On-Track Position
The carriage moves one track for each operation of the
forward/reverse switch.
Ten-Track Position
The carriage moves through a nominal 10 tracks for each
operation of the forward/reverse switch. (The number of
tracks moved is dependent upon the starting address; the
1-34 (5/70)
10TRACKS 0
HD 0
0
DC Box
0 HD 1
1 TRACK Q 0 HD 2 FORWARD
ON LINE O
~
. 0 HD.3
fe
(Off)
\ /REVERSE
CE Mode-Select Switch.,_\--z-F--orw-a-rd_/_R_ev-er_s_e S_w_i ...... tch
FigUre 1-6 3. CE Control Panel
[07524)
address at which the carriage stops is dependent upon
the direction of travel.)
Forward Travel: Starting from track 000, the carriage
moves to track 011, then to track 021, 031, and so on,
for successive operations of the forward/reverse switch.
When starting from an intermediate track, track 024 for
instance, the carriage moves to track 031 , 041, and so
on.
Reverse Travel: Starting from track 202, the carriage
moves to track 199, then to track 189, 1 79, and so on
for successive operations of the forward/reverse switch_
When starting from intermediate tracks, track 167 for
instance, the carriage moves to track 159, 149, and so
on.
Head 00 Position
Selects the upper head of the upper removable disk.
Head 01 Position
Selects the lower head of the upper removable disk.
Head 02 Position
Selects the upper head of the lower fixed disk.
Head 03 Position
Selects the lower head of the lower fixed disk.
Forward/Reverse Switch
• The forward/reverse switch determines the direction
of travel of the carriage when the 5444 is under CE
control.
The forward/reverse switch is a three-position toggle
switch, biased towards a central off position. The switch
is used with the 'l Track' and '10 Track' positions of the
mode select switch, to determine the direction of
carriage movement; in the forward position, the carriage
moves towards the center of the disk; in the reverse
position, the carriage moves away from the disk center.
Section 2. Maintenance Facilities
CE CYLINDER
• One cylinder on each disk is reserved for fault finding.
• Customer access to the CE cylinder is inhibited.
Cylinder 203 on Models 2 and 3, and cylinder 103 on
Model 1 are reserved for fault diagnosis of the read/write
circuits. The CE has, therefore, four tracks available on
Models 1 and 2, and two tracks on Model 3.
Customer access to the CE cylinder is inhibited by the
operating system program. (Customer access is limited to
cylinders 000 to 202 on Models 2 and 3, and 000 to 102
on Model l.)
CE DISK CARTRIDGE
• Used during maintenance.
• Assists circumferential adjustment of the upper index
transducer.
•
A~ists
adjustment of the head/arm assemblies.
• Two pre-recorded cylinders (005 and 073) are used in
these adjustment procedures.
A CE disk cartridge contains two pre-recorded cylinders,
005 and 073, which are used during adjustment
procedures to the head/arm assemblies and to the upper
disk index transducer. Cylinders 004, 005, 006, and 071
through 075, should not be written on, otherwise the
pre-recorded information will be destroyed. Any other
cylinders may be used for test purposes.
The CE cartridge is identified by its black top cover
and white bottom cover. (Customer cartridges have a
blue top cover with the white bottom cover.)
Cylinder 005
Cylinder 005 is used for circumferential adjustment of
the upper index transducer and has a single flux
transition marker recorded 180° from the center-line of
the index slot. To assist in identifying this marker it is
followed after 10µ.s by a train of pulses.
Cylinder 073
Cylinder 073 is used for adjustment of the head/arm
assemblies. Two concentric cylinders either side of
cylinder 073 are spaced 0.010 in. (0,25 mm) apart. The
cylinders are written with slightly different frequencies;
head arm tracking adjustment is carried out by
monitoring the beat frequency at cylinder 073.
TRACK POSITION INDICATION
• A scale and pointer indicates the carriage position to
the nearest ten tracks.
• Fine track position indication is obtained from
numbered track crossing slots on the drive disk.
Track position indicators indicate the location of the
read/write heads over the recording area. Coarse
indication (that is, within 10 tracks) is provided by a