EASYBASE FILE FORMAT

EBF FILE FORMAT

This document is an extract from the manual for the EASYBASE database system
sold by Q-Celt Computing.


Offset  Type          Description

* General file structure details

0     dc.b 4          'EBF2' file identifier
4     ds.l 1          length of file as saved
8     ds.l 1          number of records including "highest$"
12    ds.l 1          total number of fields
16    ds.l 1          length of each record
20    ds.l 1          offset from base to start of record 0
24    ds.l 1          reserved
28    ds.w 1          length of database name
30    ds.b 20         text of name of database


* 100 field names list starts 50 bytes in
* this needs 2000 bytes total

50    ds.w 1          field width in characters (even value)
52    ds.w 1          length of field name
54    ds.b 16         field name (max 16 characters)
(repeated 100 times)


* table of field offsets within record, pointers to start of
* each field from first byte of each record, so first entry
* is always 0, and the pointers are to the length word, NOT
* to the text of each field 200 bytes total

2050  ds.w 100        field start (length word) offsets


* records start here, 2250 bytes into the file, so the fixed
* overhead is 2250 bytes of file details preamble

2250  ds.w 1          length of text in this field
      ds.b fieldwidth text of this field
      (repeated for each field in record)

      (next record, etc)

* there are also two invisible records at the end of the
* database, first is the highest possible value sort order
* delimiter, second is a temporary workspace record, used
* for entering/altering records and for swapping records.
* Both are included in the "records" count, so the user
* records count is 8(base)-2, i.e. total records - 2