Xerox 900 series Technical Manual page 46

USE:
(cont .)
METHOD:
The original level records are output on SO (LP or TV)
Example:
.6ASSIGN S = MTO, Xl = DF1Y, SO = LP
.6SYSGEN
4095.
The X2 and Xl fi
I
es are then begun foil owi ng the Sand D fil es.
Levell identifiers are discarded from the output (Xl) file during SYSGEN;
level 2 records are abbreviated to the first four words.
When the end of the Old System Tape (OST) is reached, the Sand D fi
I
es
are closed, the OST is rewound, and control is returned to MONARCH.
SYSGEN uses the resident RAD package in performing all RAD I/O operations.
The design and operation of SYSGEN is similar to that of UPDATE, except
that no editing capability is provided. That is, the complete Old System
Tape is copied onto the RAD without modification.
SYSGEN consists of two separate programs:
SYSGE N
1:
a RAD bootstrap
SYSGEN 2: performs the SYSGEN
operation
SYSGEN 2 performs the following steps:
1.
Initializes the RAD EOM/SKS table in the File Management Routine to
correspond to the unit and channel assignment specified in QSYST
(UAT(X 1)).
2. Initializes the UAT entries utilized during SYSGEN.
3.
Initializes the file pointers maintained within the File Management
Routine.
4.
Writes SYSGE N
1
(the RAD Bootstrap) onto RAD sectors
0
through 2, to
permit subsequent bootstrap of the system from the RAD.
5.
Rewinds the Old System Tape and bypasses the tape bootstrap.
6.
Copies the OST records to the RAD, beginning with sector
3.
During the
process, .61 records are discarded, but their labels are entered into a
Directory file that is maintained at the end of the RAD, as allocated by
the
SYSGE N
message. Each such entry is three words in iength, and in-
cludes the RAD (word) address at which the so-labeled file begins •
.62 records are abbreviated to the first four words.
Blocking sentinels are re-
move(r~'"'-
' - ' - .'
~
....
_~C'
41