#ident	"@(#)xl:README	1.1"

         Archive XL Floppy Tape Utilities - Version 1.0








		   I N T R O D U C T I O N





The Archive XL Floppy Tape Utility supports Archive model 3800 streaming
1/4-inch mini cartridge tape drives, or any floppy tape drive that 
supports the QIC-107 physical and QIC-117 logical interface specifications
and QIC-80 or QIC-40 recording format standards. 

The Archive model 3800 drive is compatible with QIC-80 (both read and write)
QIC-40 (read only) recording formats. These industry standards govern the 
physical and logical configuration of recording data on a standard 1/4-
inch mini data cartridge such as 3M's DC-2000.

The floppy tape is a low cost tape device which operates at 500 Kbps
transfer rate, about 1/4 of the standard full size 1/4-inch tape speed.
The speed difference is mainly due to the fact that the floppy drive sharing
the floppy disk controller with the floppy disk drives. The elimination
of the cost of a separate tape controller keeps the total system cost
to minimum.








         		August 22, 1989

1. Missing Items

   Three ioctl's: XL_ERASE, XL_AMOUNT and XL_RFM are not implemented. 
   The ERASE ioctl was left out due to the absence of the erase head in 
   the Archive XL-80 drive.


2. Problems with this release

2.1 Floppy tape can not operate simultaneously with floppy disk:

    The floppy tape driver, xl, was written as an independent device 
    to the floppy disk controller even though the controller is 
    being shared by both the floppy disk and the floppy tape drives. 
    The floppy disk driver, fd, and the floppy tape driver, xl, each
    maintains a queue to process the requests. There is no provision
    to allow command interleaving between floppy disk and tape drives.

    Furthermore, due to the fact that both the xl and fd are independent
    drivers, to avoid floppy disk operations interfere with the
    floppy tape operations, the standard fd driver must be modified 
    to prevent both fd and xl device opened at the same time. 

    The modified fd.c is included in this package. It should be kept
    current with the official fd.c release.

2.2 Fdcerr occurs on a busy system:

    On a busy system, the following error message occasionally happens:

	fdcerr: ST0=00000041 ST1=00000004 ST2=00000004

    This will slow down the tape operation substantially. However,
    the xl driver usually will retry and always be able to recover.

2.3 Timeout with excessive ECC error:

    Normally the xl driver will make many attempts to recover itself 
    from ECC error. However, if the problem persists for a long time,
    xl driver eventually will timeout and issues a timeout message.
    The system may appear to be hanging during the retry.
    
    The timeout error has been known to happen in the following situations:

	1. Bad DC-2000 tape

	   A tape may be improperly formatted, unformatable due to
	   damaged media, or other tape related problem.

	2. Bad floppy tape drive

	   The read/write head alignment problem is the most often 
           found problem with the floppy tape drive. A tape formatted
	   by one drive may not be read or write flawlessly on another i
	   drive.

	   This problem ususally can be corrected by reformat the 
	   tape on the target tape drive again.


3. Generations Instructions


   To make installpkg binary:

	# make -f xl.mk install package

   then copy installpkg binary to floppy:

	# dd if=/tmp/*.xl of=/dev/dsk/f0q15d bs=4096

   To install the driver:

	Insert the installpkg floppy in driver 0, then type

	# installpkg

   To clear up all directories:

	# make -f xl.mk clobber


4. Components of this delivery

add-on
add-on/xl
add-on/xl/ID
add-on/xl/ID/Files.sh
add-on/xl/ID/Install
add-on/xl/ID/Makefile
add-on/xl/ID/Master.sh
add-on/xl/ID/Name.sh
add-on/xl/ID/Node.sh
add-on/xl/ID/Remove
add-on/xl/ID/Size.sh
add-on/xl/ID/Space.c
add-on/xl/ID/System.sh
add-on/xl/cmd
add-on/xl/cmd/Makefile
add-on/xl/cmd/ftapecntl.c
add-on/xl/io
add-on/xl/io/Makefile
add-on/xl/io/awk.sh
add-on/xl/io/xl.c
add-on/xl/io/xl.h
add-on/xl/io/xl_dec.c
add-on/xl/io/xla.orig.s
add-on/xl/io/fd.c
add-on/xl/pkg
add-on/xl/pkg/Makefile
add-on/xl/README
add-on/xl/sys
add-on/xl/sys/Makefile
add-on/xl/sys/ftape.h
add-on/xl/uface
add-on/xl/uface/Makefile
add-on/xl/uface/Menu.tape
add-on/xl/uface/Text.fop
add-on/xl/uface/Text.sop
add-on/xl/uface/Text.tape
add-on/xl/uface/admin.sh
add-on/xl/xl.mk
