On 12/9/2013 2:56 PM, Skip Robinson wrote:
Not sure what's meant by having to chain CCWs. I just finished updating an old RYO program that writes 80 byte records to any device specified because I needed to test >32K blocks on tape. I merely added a DCBE with BLKSIZE=0 and pointed to it in the existing DCB. No other changes. Created a tape file with BLKSIZE=261760 (256K) (as reported by RMM) by specifying that block size in JCL. No attempt at chaining, which I would not know how to do anyway.
1) The access method does the chaining for you. If you make the device not ready while its reading or writing, and take a dump, you will find both the xSAM CCWs and the converted CCW(s) and the IDAL.
2) That's a shame. Every programmer can benefit from familiarity with the hardware - write a test program using EXCP to read a multi-volume tape, or use XDAP to read a multi-volume DASD data set with unknown block sizes.
Gerhard Postpischil Bradford, Vermont ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
