9 May
2012
9 May
'12
2:02 p.m.
On Wed, 9 May 2012 09:04:07 -0700, "Michael Holley"
<swtpc6800 at comcast.net> wrote:
I was told the load from hard disk was page fault the
swapped the desired
data back into memory.
Michael Holley
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org]
On Behalf Of Tom Uban
Sent: Wednesday, May 09, 2012 5:33 AM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: More photos from VCF East 8
One note on the PDP-11/03 booting the VAX-11/780, the PDP-11/03 first loads
the microcode into the VAX-11/780, thereby defining the machine's higher
level of operating code, then a bootstrap to load from a particular hard
disk or tape is run. On most PDP-11s, the microcode is stored in ROMs or is
hard wired.
VMS always loads a program by page faulting it into memory. That
mechanism would AFAIK not work for booting, because the whole paging
software, disk drivers etc would have to be loaded and initialized
first. I don't remember offhand what it says in the VMS internals book
about booting, but I could look it up.
/Jonas
10 May
10 May
7:40 a.m.
On Wed, May 9, 2012 at 5:02 PM, Jonas Otter <jonas at otter.se> wrote:
On ?Wed, 9 May 2012 09:04:07 -0700, "Michael
Holley" <swtpc6800 at comcast.net>
wrote:
I, too, would have to look up details, but from what I remember about the 11/730
(which has an 8085 as a front-end processor, not a PDP-11, but AFAIK, the
general principles still apply), the FEP loads VMB.EXE from the console medium
(RX01 for the 11/780, TU58 for the 11/730) into VAX main memory then kicks the
processor into run mode.
The 11/750 is a different beast - it has native boot ROMs and no FEP (there's
an A-D selector switch, and there are several common arrangements of boot
ROMs, including for third-party disk controllers)
-ethan
I was told the load from hard disk was page fault the swapped the desired
data back into memory.
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org]
On Behalf Of Tom Uban
Sent: Wednesday, May 09, 2012 5:33 AM
One note on the PDP-11/03 booting the VAX-11/780, the PDP-11/03 first
loads the microcode into the VAX-11/780, thereby defining the machine's
higher level of operating code, then a bootstrap to load from a particular
hard disk or tape is run. On most PDP-11s, the microcode is stored in
ROMs or is hard wired.
VMS always loads a program by page faulting it into memory. That mechanism
would AFAIK not work for booting, because the whole paging software, disk
drivers etc would have to be loaded and initialized first. I don't remember
offhand what it says in the VMS internals book about booting, but I could
look it up.
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