ijpds formats.book - Kodak

Appendix D. Indexing and Multi-File IJPDS
Basic Index Files (for Single-File IJPDS Jobs)
Basic Index Files (for Single-File IJPDS Jobs)
D - 2 IJPDS Formats
For GEORGE.IJP the index file is GEORGE.NDX in the same directory.
An index file is a file of two or more 32-bit words which are file offsets into
the IJPDS file. Each word is the offset to the block containing the
document being indexed (not the offset of the SDC). Words are 32-bit (it
does not matter if they are signed or unsigned; the maximum value is
2GB, not 4GB) integers in Intel byte-order. (The OS/2-hosted Pentium
controller will use the values directly in fseek() operations.)
The first word is the offset to the block containing the earliest SDC for
Document 1 (whichever RIP that may be); this is always present.
The last word is the offset to the block containing the earliest SDC for the
last document (whichever RIP that may be); this is always present.
If the IJPDS file has more than 99 documents, then additional words are
in the index file (between the first word and the last word) with offsets to
the blocks containing the earliest SDCs for Documents 100, 200, 300,
400, etc. If the file ends with a document number that is a multiple of 100,
then the next-to-last index entry will be the pointer for the last multiple-of-
100 document, and the last entry will be, as always, the pointer to the last
document (even though in this case the last two entries are the same).
Here are some example index files:
IJPDS file Index file
87 documents 2 entries
125 documents 3 entries
800 documents 10 entries
801 documents 10 entries
Entries
for
document
1
87
1
100
125
1
100
200
300
400
500
600
700
800
800
1
100
200
300
400
500
600
700
800
801