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From: terry@spcvxb.spc.edu (Terry Kennedy, Operations Mgr)
Newsgroups: comp.sys.dec
Subject: Re: How to boot from TS11?
Message-ID: <1990Aug17.003636.474@spcvxb.spc.edu>
Date: 17 Aug 90 04:36:36 GMT
References: <1990Aug14.160717.179@murdoch.acc.Virginia.EDU> <1990Aug14.234113.462@spcvxb.spc.edu> <57054@wlbr.IMSD.CONTEL.COM>
Organization: St. Peter's College, US
Lines: 22

In article <57054@wlbr.IMSD.CONTEL.COM>, sms@WLV.IMSD.CONTEL.COM (Steven M. Schultz) writes:
> 	There is a console ODT routine in the back of the 4.3 system
> 	manglers guide for TS drives, but it's only for 750/780/86XX
> 	machines.  I haven't the foggiest  what would need to be done on
> 	a uVax... 

  Indeed. Provided you have a tape with something bootable on it, you can
fabricate a bootstrap. I guess my VMS bias is showing 8-), but on VMS the
only useful bootable items are BACKUP and (possibly) BAD, and there isn't
any support to boot these from non-MU devices.

  The basic problem is that VAXen have too many possibilities for data
paths to the tape controller. On the PDP-11, you had a controller which
was accessed the same way on all models. With VAXen, you have the Unibus
adapter (well, not on a MicroVAX, but...) and it comes in various flavors.
The code given in the quoted note works fine for the machines which use
the DW750/780 adapter, but (for example) on a 6000 with a BI to Unibus
delay line 8-{, the programming is rather complex.

	Terry Kennedy		Operations Manager, Academic Computing
	terry@spcvxa.bitnet	St. Peter's College, US
	terry@spcvxa.spc.edu	(201) 915-9381