31 May
2001
31 May
'01
12:41 a.m.
How does a PDP-11 boot from an RQDX3 controller?
I have several 11/23's based on the KDF11-AA CPU, which has no on-board boot ROM. The
Andromeda UDC11 disk controller that most of these use contains the boot ROM. These
machines are in a 4-slot dual-wide card cage which is full. There is the CPU, a memory
card, the disk controller, and a serial card.
A couple of these machines are missing the disk controller. RQDX3's seem to be readily
available, and there is adequate documentation of the card on the web (jumpers, cable
pinouts, etc). Will the KDF11-AA be able to boot from an RQDX3?
If not, can anyone suggest an good alternative?
--
Jonathan Engdahl Rockwell Automation
Principal Research Engineer 24800 Tungsten Road
Advanced Technology Euclid, OH 44117 USA
Euclid Labs http://users.safeaccess.com/engdahl
31 May
31 May
6:55 a.m.
Jonathan Engdahl wrote:
How does a PDP-11 boot from an RQDX3 controller?
Jerome Fine replies:
Why are you bothering with an old PDP-11/23? There are much faster
systems that are readily available and since you have ONLY four serial
channels (I presume that you are using an M8043/DLV11-J module),
why would you not switch to a faster, more capable system? Unless
you just like the actual hardware in which case you should not mind
the following answer:
Usually from a program stored somewhere in memory. The storage
is almost always on an EPROM, but on occasion it can be on a
sheet of paper. I suppose that for someone who has a photographic
memory, the storage media would be in their brain. In any case, after
the system receives this PRIMARY BOOT program in a form that
it can use, the next step is to read the secondary boot program from
block zero of the media - in your case, the hard disk drive. If you are
willing to spend about 5 minutes typing in a PRIMARY BOOT
program each time you power on the system, them, the RQDX3 can
be used.
If the answer is yes, I will be happy to locate a suitable BOOT program
and type it in for you. I seem to remember it was about 75 words of
code and data, but that could be wrong.
Not that this program would also boot a floppy with XXDP so that
you would be able to format the hard drive.
Please reply if you want me to find it.
Sincerely yours,
Jerome Fine
--------------------------------------------------------------------------------------------------------------------------
I have several 11/23's based on the KDF11-AA CPU, which has no on-board boot ROM. The
Andromeda UDC11 disk controller that most of these use
contains the boot ROM. These machines are in a 4-slot dual-wide card cage which is full.
There is the CPU, a memory card, the disk
controller, and a serial card.
A couple of these machines are missing the disk controller. RQDX3's seem to be readily
available, and there is adequate documentation of the
card on the web (jumpers, cable pinouts, etc). Will the KDF11-AA be able to boot from an
RQDX3?
If not, can anyone suggest an good alternative?
--
Jonathan Engdahl Rockwell Automation
Principal Research Engineer 24800 Tungsten Road
Advanced Technology Euclid, OH 44117 USA
Euclid Labs http://users.safeaccess.com/engdahl
30 May
30 May
8:45 p.m.
JHF, et al:
Would 30+ lines of assembly always be required?
I've been playing stupid (no guesswork there) with some of my
older systems for some time now; getting in to it slowly, just leaving
them configured in as found condition.
I thought DEC 11's all did higher level booting with a memory
mapped address in the pre-Vax and with named console
devices in the Vaxes.
Are you then saying that adding a disk controller card always
requires adding a matching boot (E(P(ROM))? ('Duuh' -JEA)
John A.
1 Jun
1 Jun
1:34 a.m.
At 04:45 AM 5/31/01 -0400, John A. wrote:
Are you then saying that adding a disk controller card
always
requires adding a matching boot (E(P(ROM))? ('Duuh' -JEA)
John A.
Yup, this is why third party disk controllers always include a 'boot rom'
option. I happen to prefer the RQ11D series (or Webster) boards for 11's
since not only will they chop up biggger drives to look like smaller drives
but they include a bootstrap on board.
--Chuck
5:02 a.m.
Yup, this is why third party disk controllers always
include a
'boot rom' option.
The sound I was looking for: ROM on card itself.
Now: How common?
Is this saying that DEC controllers will force moving the ROM
out to the bus term card as a seperate FRU? And is it really
always controller card resident for the 3rd partiers?
John A.
5:40 a.m.
So far I have never seen a third party Q-bus disk interface card that
did _not_ include a PDP-11 boot rom. I'm sure they exist but they
weren't made by the 'name' brands (CMD, Dilog, Emulex, etc) The funny
thing is that the boot may consist of four 64 x 4 TTL ROMs which look
like any other chip.
--Chuck
P.S. Does anyone know if you can convert a CMD CQD200/T into a CQD200/TM
? I like that it can talk nice to my exabyte but it would be even nicer
if it could talk nice to my disks too :-)
John Allain wrote:
Yup, this is
why third party disk controllers always include a
'boot rom' option.
The sound I was looking for: ROM on card itself.
Now: How common?
Is this saying that DEC controllers will force moving the ROM
out to the bus term card as a seperate FRU? And is it really
always controller card resident for the 3rd partiers?
John A.
6:45 a.m.
Putting a ROM on the disk controller at 173000 is the usual way
of doing it, but here's a slick alternative that is used on the
DSD 4140 floppy controller:
There is no ROM onboard other than the microcode for the AMD
2901 (one 4-bit slice!), but there is a single register mapped
onto the Qbus at 173000. If the PDP-11 jumps there, the
controller gives back a jump-to-self opcode. While the PDP-11 is
busy chewing on that, the 2901 sees what has happened and copies
sector zero from the floppy to address zero via DMA, then it
changes the contents of 173000 to "CLR PC", which causes the
PDP-11 to execute the boot code.
So just because you don't see ROMS doesn't meant the board can't
boot.
--
Jonathan Engdahl Rockwell Automation
Principal Research Engineer 24800 Tungsten Road
Advanced Technology Euclid, OH 44117 USA
Euclid Labs http://users.safeaccess.com/engdahl
31 May
31 May
8:09 a.m.
Jonathan
Engdahl wrote:
How does a PDP-11 boot from an RQDX3 controller?
Jerome Fine replies:
Why are you bothering with an old PDP-11/23? There are much faster
systems that are readily available and since you have ONLY four serial
channels (I presume that you are using an M8043/DLV11-J module),
why would you not switch to a faster, more capable system?
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allain＠panix.com -
cmcmanis＠mcmanis.com -
engdahl＠cle.ab.com -
jhfine＠idirect.com