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Subj:	Patch to TCOPY - enable tape data caching

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Date: 19 Sep 90 19:50:52 GMT
From: ingr!b11!wilson@uunet.uu.net  (Jon Wilson)
Organization: Intergraph Corp. Huntsville, AL
Subject: Patch to TCOPY - enable tape data caching
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For those of you that use Roger Jenkins' tape copy program, TCOPY, here's an
obvious modification that I hadn't thought of until recently. It will enable
the tape data cache on drives that have one (such as Digital's TU81+, TA90,
TK70). If you don't use one of these drives all the time, don't worry, it
will simply be ignored on drives that do not have a cache. 

This can greatly speed copies to streaming drives. Of course, if the drive
fails between the data being placed in the cache and the actual write of the
data, you lose. Use with caution. 

This change is to TCOPY version 3.13. Simply change the line reading:

OUT_MOUNT_FLAGS:
	.LONG	MNT$M_FOREIGN	; OUTPUT FLAGS

to

OUT_MOUNT_FLAGS:
	.LONG	<MNT$M_FOREIGN!MNT$M_TAPE_DATA_WRITE>	; OUTPUT FLAGS

and enjoy.
 ______________________________________________________________________________
|                                      |                                       |
| Jonathan Wilson                      | Rob Pike on the Xwindow system:       |
| DEC Systems Support                  |                                       |
| Intergraph Corporation               |  "I have never seen anything fill up  |
|                                      |  a vacuum so fast and still suck."    |
| email: uunet!ingr!b11!stealth!jon    |                                       |
| phone: (205) 730-6397                |  - Quoted in _UNIXWORLD_, Sept. '90   |
|______________________________________|_______________________________________|

