Paul Gilmartin wrote: > I had imagined the TMP interposed its own filter behind BSAM/QSAM. > Educate me: How, outside the TMP, can one code a call to BSAM or > QSAM to perform folding? Is there something line DCB=(OPTCD=FOLD)?
You can't. No, there isn't. OPEN device-dependent code itself will detect the TERM=TS allocation and setup a specific access method- dependent GET / PUT routine, which is where the folding occurs (or at least did occur the last time I looked at the MVS source). It's not that hard to understand. If the device allocated to the DD statement is ordinary DASD, then MACRF-specific code will be selected that generates CCWs to read from the tracks allocated to the data set on disk. If the device allocated is the terminal then obviously different code has to be used. The code selected is a "compatibility interface" (like the one used for BSAM and QSAM when a JES SPOOL data set is allocated to the DDname) and it does what it does. And one of the things they do is to fold lower case characters to upper case. The TMP has absolutely nothing to do with it. It's all in the access method compatibility interface (although it was not, at first, called that, since it came out with TSO in OS/360 20.01 and 20.1). But the same mechanism was then later used in OS/VS2 2.0 (MVS) to plug in the ACB/RPL compatibility interface layer. -- WB ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
