From: Ethan Dicks
Sent: Tuesday, May 08, 2012 10:08 PM
On Tue, May 8, 2012 at 11:27 PM, B Degnan <billdeg at degnanco.com> wrote:
  You wrote: 
    "Mike Ross' exhibit consisted of a PDP
11/05 used to interface with
   a PDP 15, in two racks. He demonstrated restoration techniques for
   attendees. I am not sure exactly what you call this console, there is
   no "PDP 15" on the panel, but I assume it's some kind of I/O device
   that complements the (not pictured) PDP 11/05 used to presumably
   bootstrap this thing." 
  That _is_ the PDP-15 front panel - if you look, there
are 18 data
 bits.  The PDP-15 CPU was the large spread of M-series cards on the
 backplane above this front panel.  Its memory was in a black box below
 (and not there for much of the weekend).  The PDP-11/05 is
 self-contained and does the same job as the PDP-11/03 in a VAX-11/780
 or the PDP-11 in various models of PDP-10.  In each case, the PDP-11
 boots from its own ROMs to start up enough code to feed the larger
 processor.  In the case of the VAX-11/780, the PDP-11/03 has one RX01
 floppy drive.  I don't know what this PDP-11 uses, but there must be
 some local mass storage that's part of the scheme. 
Only the KL-10 uses an 11/40 as a boot processor like the 11/03 in a
780.  The KS-10 uses an 8080, and earlier models booted directly from
paper tape or DECtape; it's not clear to me yet whether a KI-10 could
boot directly from disk, but I tend to doubt it based on what I'm seeing
in ours.
Rich Alderson
Vintage Computing Sr. Systems Engineer
Vulcan, Inc.
505 5th Avenue S, Suite 900
Seattle, WA 98104
mailto:RichA at 
vulcan.com
mailto:RichA at 
LivingComputerMuseum.org
http://www.LivingComputerMuseum.org/