Pete Turnbull wrote:
David Riley wrote:
On Jan 6, 2012, at 6:37 AM, Pontus wrote:
> The topic says is all, can a PDP-11/23 (on a
M8189 card) boot from
> MSCP devices? My guess is that you need proper roms on your BDV11 ?
> Would these usually be included?
The M8189 is a quad-height 11/23-plus card which includes bootstrap,
LTC, SLUs, etc and there wouldn't normally be a BDV11 in the same
system. The M8186 is the dual-height 11/23 card, and that would
normally have a BDV11 in the system. The original 11/23-plus
bootstrap ROMs are modified versions of the BDV11 boot ROMs and have
the same boot options -- no MSCP. Those ROMs would be labelled
23-339-01E2 and 23-340-01E2 (or sometimes 23-339E2 and 23-340E2).
MSCP boot devices (RQDXn) can be booted with any Qbus 11 cpu. The
16/18/22 bit
this is a red herring in that it's a dont care save for address space.
However like Pete has said the BOOT program is device specific and some
of the 11/23CPUs
(M8186) have no boot roms at all and depend on the BDV11 to carry the roms
where the later M8189 had the boot roms on the board along with serial
ports. The Even then there were two version and the primary difference
was what Eproms were installed.
Where the 11/23 vs 11/23+ differed si what devices the BOOT rom knew about.
So the real comment should be not can a PDP11/23 boot MSCP? As the
answer is yes
with the provision that the rom at the boot address (nominally 173000)
contains MSCP
boot.
Certainly mine can (8189 with BH roms).
Technically, it's an 11/23+,
but the only real difference from a /23 is the address lines (22 in
the /23+).
That's not quite right. The early 11/23 cards (M8186 dual-height) are
only 18-bit but all Rev.C and later 11/23 cards are 22-bit. All
M8189 are 11/23-plus cards and are 22-bit.
And most of the pre rev-C could do Q22, save for they were not tested or
qualified for it unless it was missing the second chip that provided the
MMU.
Without that chip its only Q16.
The only difference between different M8189 cards
(apart from
inconsequential etch revisions) are the boot ROMS. The original release
-BA are 2K ROMs equivalent to BDV11 boot ROMs and they were used in
PDP-11/23-plus systems (BA11S box). Later ones such as -BE and
onwards that support MSCP were made specifically for microPDP-11/23+
systems (BA23 box).
The KDF11-B CPU System Maintenance manual
(EK-245AA-MG-001) indicates
that all versions of the ROM should be able to boot MSCP, if I'm
reading it right.
No, the oldest versions can't. Only the ones intended for
microPDP-11/23+ system have MSCP support (-BE and later).
The oldest versons would require the user to use ODt to enter a rather long
boot program to boot MSCP. the alternate is if that older system has
both an
RX01/2, RL01/02/ RK/TU58 and a booter on that device you could boot of
those and do a boot/foreign (RT11) to the MSCP device.
I do that on my tU58 based 6 board system wich is all dual width with
11/23, 512KB ram, DLV11j, RQDX3, MRV11 with TU58 boot). Boot Tu58 with
Rt11 and usethat to boot the
MSCP (2x RD52 31mb each) with usually RT11 but the second hard disk has
RSTS.
It's what DEC would call an unsupported configuration but by the book
doable.
Allison