TAPESL Macro

Use the TAPESL macro to process IBM standard HDR1 and EOF1 labels without using DOS or OS OPEN and CLOSE macros. You will probably use TAPESL with the RDTAPE, WRTAPE, and TAPECTL macros.

TAPESL processes only HDR1 and EOF1 labels. It does not perform any functions of opening a tape file other than label checking or writing. It is used both to check and to write tape labels. A LABELDEF command must be entered before running the program that contains this macro. The LABID parameter of the TAPESL macro specifies the name of the LABELDEF to be used. For example, if you use the macro
TAPESL HOUT,181,LABID=GOODLAB
in your assembler language program, you must supply a LABELDEF command for GOODLAB:
labeldef goodlab fid file10 fseq 4 exdte 002235
The tape must be correctly positioned (at the label to be checked or at the place where the label is to be written), before you run the macro. The TAPECTL macro can be used to position the tape. TAPESL reads or writes only one tape record unless you specify SPACE=YES for input. Then it spaces the tape to beyond the tape mark that ends the label file. TAPESL reads and checks a tape VOL1 label provided the tape is positioned at load point and you have specified a volume ID in your LABELDEF command.