When data is transferred from the SESAM-DBAccess server to the client computer, DBAccess converts this data from EBCDIC.DF4.04 to ISO8859-1 (8-bit ASCII) and vice versa.
However, if a different conversion is necessary, e.g. if national character sets are used or the data has other peculiarities, DBAccess allows you to specify the required ASCII conversion individually for every EBCDIC character in the SYSDAT.SESDBA.091.EBCASC conversion table. However, you can only change the notation for special characters.
This file has the following default contents:
# Converting EBCDIC.DF.04 to ISO8859-1 (ASCII 8 bit) # This conversion table differs from standard conversion in following items: # - EBCDIC 0x15 Newline -> ASCII 0x0a Newline instead of 0x1a # - EBCDIC 0x25 -> ASCII 0x85 instead of 0x0a # - The conversion is extended to a bijective conversion # EBCDIC->ASCII # -0 -1 -2 -3 -4 -5 -6 -7 -8 -9 -a -b -c -d -e -f 0- 00 01 02 03 9c 09 86 7f 97 8d 8e 0b 0c 0d 0e 0f 0 01- 10 11 12 13 9d 0a 08 87 18 19 92 8f 1c 1d 1e 1f 1 12- 80 81 82 83 84 85 17 1b 88 89 8a 8b 8c 05 06 07 2 23- 90 91 16 93 94 95 96 04 98 99 9a 9b 14 15 9e 1a 3 34- 20 a0 e2 e4 e0 e1 e3 e5 e7 f1 60 2e 3c 28 2b 7c 4 45- 26 e9 ea eb e8 ed ee ef ec df 21 24 2a 29 3b 9f 5 56- 2d 2f c2 c4 c0 c1 c3 c5 c7 d1 5e 2c 25 5f 3e 3f 6 67- f8 c9 ca cb c8 cd ce cf cc a8 3a 23 40 27 3d 22 7 78- d8 61 62 63 64 65 66 67 68 69 ab bb f0 fd de b1 8 89- b0 6a 6b 6c 6d 6e 6f 70 71 72 aa ba e6 b8 c6 a4 9 9a- b5 af 73 74 75 76 77 78 79 7a a1 bf d0 dd fe ae a ab- a2 a3 a5 b7 a9 a7 b6 bc bd be ac 5b 5c 5d b4 d7 b bc- f9 41 42 43 44 45 46 47 48 49 ad f4 f6 f2 f3 f5 c cd- a6 4a 4b 4c 4d 4e 4f 50 51 52 b9 fb fc db fa ff d de- d9 f7 53 54 55 56 57 58 59 5a b2 d4 d6 d2 d3 d5 e ef- 30 31 32 33 34 35 36 37 38 39 b3 7b dc 7d da 7e f# # -0 -1 -2 -3 -4 -5 -6 -7 -8 -9 -a -b -c -d -e -f #
The body of the table shows the appropriate ASCII notation for every EBCDIC character indicated by the values around the margins of the table. DBAccess automatically converts values in the opposite direction (e.g. SQL statements and entry parameters) by inverting this table.
Notes
Comment lines are marked in the file with # at the first position.
For example: EBCDIC 0xF0 is converted to ASCII 0x30 according to the EBCDIC-ASCII conversion table.
The representation is bijective, i.e. every hexadecimal value in EBCDIC is paired uniquely with one hexadecimal value in ASCII and vice versa.
If you make any modifications, you must ensure that a bijective representation is created and that none of the characters which appear in reserved SQL words is modified.
Passwords are encrypted when saved and are also encrypted during transmission by the client. Thereby, there is an influence of the ASCII-EBCDIC conversion onto the passwords. For the case that the passwords include special characters and the conversion table is changed, these passwords have to be entered and encrypted again.
Generating a new conversion table
When the default name for the server's conversion table is replaced by *SESAM in the initialization file, the CCSN which is entered as the CCSN in the SESAM configuration file is used for conversion via XHCS.
The administration command WRITE_NEW_CONVTABLE <file_name> enables this new conversion table to be stored, and it can then be used as the server's new conversion table when required.
A password file can only be used with the conversion table with which it was created, see "Data entry procedure SYSPRC.SESDBA.091.USER". The new conversion table should therefore be used to generate a new password file.