Honeywell DPS 8 System Installation Manual page 147

A221 LOGICAL CHANNEL (LC) NUflBERS
Consistent with GCOS 8 software, each lMU supports (up to) 64 Logical
Channels
(LCs) consisting of (up to) 56 payload
LCs numbered 8 through
63. Like the 10M,
LCs 0 through 7 are overhaad channeis. tCs a iunused),
1 (System Faults), 2 (Connect), 5 (Bootload). and 6 (Special Interrupt)
are the same
as the 10". Unlike the 10M, LC 3 is
the HCA channei; LC 4
(Wraparound) and LC 7 (Scratchpad Access) are T&D channels and are not
applicable to the IMU (unused).
For the purposes of this dicsussion, the above are all referred to as
"Software LC" numbers.
The 56 payload Software LCs can be assigned across (up to) 16 physical
Channel Adapters/IPCs. IMU Central converts
the Software LC number into a
different
form which is understood by the Channel Adapter/IPC,
hereafter
called
the "Adapter LC" number.
Depending on GCDS 8 software and the
design of each type of Channel Adapter/IPC,
from 1 to 8 Adapter LC numbers
can be assigned to
each one. Physically, the Adapter
LC number has a
value
ranging from 0 to "n", where "n" is 7 or less. When
IMU Central
receives a Software LC number from GCOS,
it converts the number into a
physical Channel Adapter/lPC location on the IMU's internal buses and a
'corresponding Adapter LC number (from 0 to 'n").
The IMU hardware allows the base Software LC number, assigned to a
physical Channel Adapter/IPC, to be any number
from 3 thru 63; that is,
both
odd and even base numbers are accepted
by the IMU. However,
consistent with the 10M, 6605 software
restricts the base Software LC
number to a modulo-"n" number, where 'n'- 0, 2, 4, or a; see Table
A2.1-1. Like the 10M, multiple
Software LC numbers assigned to a physical
channel must be a series of consecutive numbers.
later).
There is no "wired-in" physical relationship between LC number and
physical adapter number or board slot on the internal buses. The LC
numbers assigned to each physical adapter are input configuration
parameters provided to IMU central control via the MCA. LC numbers may be
assigned to physical channels
on either bus, with no direct
effect on
priority or service rate.
APPENDIX A
REA/ 8
A2.1.1 RULES & GUIDELINES FOR LOGICAL CHANNELS
1. On the boot IMU, GCDS software requires that the System Console be
coniigured as LC 30. If the Remote Console connection exists, it is
configured as LC 31. Additional console channels may be assigned any
other remaining unused numbers within the range of 8 thru 63,
including LC 31 if there is no Remote Console connection.
2. Each physical FIPS or MPCIPSI channel connected to a DISK" Subsystem
can be configured with 1, 2, 4, or 8 LCs, with 4 LCs being the most
preferred.
3. Each physical FlPS channel connected to a TAPE Subsystem can be
configured with 1, 2, or 4 L05, with 2 LCs being the most preferred.
4. Each physical PSI channel connected to an MPC type TAPE Subsystem can
be configured with 1 or 2 LCs, with 2 LCs being the most preferred;
this is an MPC limitation and not an IMU limitation.
5. Each physical PSI channel connected to an MPC-UR Subsystem must be
configured with 1 LC for each device connected to the URP. A GCOS
software convention requires that the first LC number assigned to each
IPC-UR must be an even number; the hardware does not care.
6. Each IPC—UR/PDSI or IPC-URIDAI must be configured with 1 LC for each
device connected to it. A 6005 software convention requires that the
first LC number assigned to each IPC-UR must be an even number; the
hardware does not care.
7. The hardware allows the NDlC (Direct Channel) to be cofigured with 2
LCs, but GCOS software is constrained to 1 LC per NDIC.
8. Due to GCOS software constraints, LC number assignments for each FIPS
or PSI channel are as shown in Table A2.1-1.
9. Without exception in the field, the HYPERchannel(tm) is configured
with one LC per physical channel. The "Massnet" software is designed
to execute only one 110 operation at a time and, therefore, constrains
the configuration to one LC per physical channel. Nonetheless, the
HYPERchannel hardware in the IMU and GCOS software is designed to
accommodate up to 8 L05 per physical channel.
However, it is possible to configure additional channels on the same
physical HYPERchannel Adapter by lying on the configuration cards;
i e., by configuring the other LCs as crossbarred channels even though
they exist on the same physical channel. In an experiment, up to four
were configured this way, but you will need the help of experts in
this area if this capability is considered.
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