How does the Browse/Edit function determine which characters can be displayed in RC/Update

Products

• RC/Update for DB2 for z/OS

Issue/Introduction

Some characters on a Db2 table are not able to be displayed on screen due to their non-display format such as binary data.
How does RC/Update for Db2 for z/OS (RCU) Edit/Browse determine which characters are displayable and which are not?

Resolution

RC/Update Browse/Edit does not determine, on its own, which characters are displayable. It utilizes the ISPF/PDF translation tables to determine which characters are displayable.

To elaborate, ISPF/PDF provides a set of translation tables which define the valid displayable character set for a 3278/3279 English terminal.

RC/Update Edit/Browse depends on these translation tables in order to determine which characters are displayable in an edit/browse session.
If a particular character is non-displayable, then RC/Update Edit/Browse will display the character as a blank or period.

Sample from SYSIBM.SYSPACKAGE utilizing HEX ON to show the data. The x'0E' is displayed as a blank on the first record and the x'59' on the second record is a dot.

RUBROWC  20.0   --------- RC/Browse: Column Mode --------- yyyy/mm/dd hh:mm:ss
COMMAND ===>                                                  SCROLL ===> CSR

For Table   => SYSIBM.SYSPACKAGE               > Row number=> 1 OF 112306
Browse Mode => C                                 Max Char  => 070
SSID: ssid ----------FETCH STATUS: COMPLETE-------------------------- authid1
      CONTOKEN
       ¬   1
      05110F44
      EFFD9100
--------------
         . e
      12051801
      A74965EE
--------------

It is necessary to customize ISPF/PDF's translation tables in order to display characters such as the EURO dollar sign (x'9f'), which by default is non-displayable.

Detailed instructions for doing so can be found in the IBM manual "ISPF Planning and Customizing", sub-sections 'Creating ISPF Translation Tables' and 'Creating PDF Translation Tables'.

Overall, the process involves updating the ISROWNTT and ISPOWNTT samples (which can be found in the ISP.SISPSAMP sample library), and re-assembling them as ISR3278/ISP3278 respectively (assuming your terminal type is a 3278).

Additional Information

The only table that absolutely MUST be updated, for RC/Update Edit/Browse purposes, is the TTETO table in ISROWNTT. However, ISPF/PDF may not function properly if you do not make all necessary changes to the other tables as well.