Copying Foreign Tapes

Mount the tape on your HP 3000 (without a write ring). The automatic volume recognition message tells you if it is labeled, and if so, what the label is. If the tape is ANSI-labeled, the character data is probably in ASCII, but if the tape is IBM-labeled, the character data is almost certainly in EBCDIC.

Use FCOPY to dump one or two blocks of data from the tape. If the data is likely to be EBCDIC characters, then use EBCDICIN. For example, if the tape was reported as "Vol 000001,IBM", you could do this:

   FILE L;DEV=TAPE;LABEL=000001,IBM;REC=-16384,1,U,ASCII



   FILE LP;DEV=LP



   FCOPY FROM=*L;TO=*LP;OCTAL;CHAR;EBCDICIN;SUBSET=,1

This reads one block from the tape, converts it to ASCII, formats it as both octal and characters, and prints it, telling you how big it is. The tape records may be blocked, and examination of the data will probably disclose a pattern of repetitions from which the blocking factor can be deduced. This is necessary more often with unlabeled tapes or IBM-format labeled tapes, which may not have the HDR2 records that give the record and block size.

Once you know the format of the data, use FCOPY to copy the data to where you want it--for example, to disk. Suppose that the above tape is found to have blocks of 2640 bytes, consisting of 20 records of 132 bytes. You could do the following:

   FILE LL;DEV=TAPE;LABEL=000001,IBM;REC=-132,20,F,ASCII



   FILE IBMDATA;REC=-132,F,ASCII;DISC=12000,32



   FCOPY FROM=*LL;TO=*IBMDATA;NEW;EBCDICIN

You need an estimate of the amount of data on the tape. If you underestimate, the disk file fills up and FCOPY terminates, leaving some data unread. If you overestimate, you waste some disk space, but you can reduce the amount wasted if you specify a large number of extents (32 in the example).