BTAM - Basic Tape Access Method

BTAM is an access method for block-oriented tape processing; it can even be used to process tape files which were not created with BTAM. While a tape file is being processed, the processing direction within the file can be changed as desired. The tapes can be positioned by block or by section as desired. BTAM processes files with and without standard blocking.

Macros for the BTAM access method

The following macros can be used by the BTAM access method:

Macro	Operation	Function
CLOSE		Service macro
EXLST		Service macro
EXRTN		Service macro
FCB		Service macro
FCBAD		Service macro
IDFCB		Service macro
IDFCBE		Service macro
LBRET		Service macro
OPEN		Service macro
BTAM	CHK	check processing status of an I/O operation.
	ERG	generate interblock gap.
	MINF	fetch medium information (only useful for volume types which contain optical disks)
	POS	position tape.
	RBID	determine tape position.
	RD/RDWT	read data info main memory and wait for completion of I/O operation.
	RDBF	read data from save area of tape cartridge buffer.
	REV/REVWT	read tape in reverse direction and wait for completion of I/O operation.
	RT/RTL	read with data transfer; with/without message if the length is less than anticipated.
	RNT/RNTL	read without data transfer; with/without message if the length is less than anticipated.
	SYNC	synchronize and determine tape position.
	WRT/WRTWT	write data from main memory and optionally wait for completion of I/O operation.
	WT	wait for completion of the I/O operation.
	BSF	synchronize and determinate tape position.
	BSR	Control code for positioning and for writing tape marks
	FSF	Control code for positioning and for writing tape marks
	FSR	Control code for positioning and for writing tape marks
	REW	Control code for positioning and for writing tape marks
	RUN	Control code for positioning and for writing tape marks
	WTM	Control code for positioning and for writing tape marks