7 Apr
2011
7 Apr
'11
5:39 p.m.
I am restoring a PDP-11/34 and am currently adding an RX-01 drive to it in order to boot
RT-11.
I have already located a copy of RT-11 on an LSI-11 system and have made a bootable RX-01
floppy (an M7946 was installed on the LSI-11 to do this). This disk was tested on the
LSI-11 system by asserting BHALT, entering a bootstrap via ODT, and booting from the disk
(which was, at the time, the only device): it boots properly and runs RT-11 version 5.04SJ
as expected.
An M7846 RX-11 controller was installed in SPC slot 9 of the 11/34, the bootstrap loaded
at 1000 via the front panel (and verified), and a boot attempted.
When STARTed at 1000, the RUN light comes on, the RX-01 head engages (as evident from the
solenoid), and you can hear the heads advancing a track or two then it stops: the "SR
DISP" led and the RUN led go out, and the display reads "005134".
Examining the bootstrap area (1000) shows the bootstrap was replaced by data.
Does anyone know what the "005134" code means? I search through RT-11 docs and
can't find anything on error codes or such and I'm hoping this will help with the
debugging.
Thanks!
Professor Mark Csele, P.Eng.
Niagara College, Canada
300 Woodlawn Rd., L-23
Welland, ON, L3C 7L3
(905) 735-2211 x.7629
E-Mail: mcsele at niagarac.on.ca
URL: http://technology.niagarac.on.ca/people/mcsele
Author of "Fundamentals of Light Sources and Lasers", Wiley, 2004
8 Apr
8 Apr
1:48 a.m.
Hello Mark.
I am restoring a PDP-11/34 and am currently adding
an RX-01 drive to it in order to boot RT-11.
Always nice.
I have already located a copy of RT-11 on an LSI-11
system
and have made a bootable RX-01 floppy (an M7946 was
installed on the LSI-11 to do this). This disk was tested on the
LSI-11 system by asserting BHALT, entering a bootstrap via
ODT, and booting from the disk (which was, at the time, the
only device): it boots properly and runs RT-11 version 5.04SJ
as expected.
OK, so far so good.
An M7846 RX-11 controller was installed in SPC slot 9
of the
11/34, the bootstrap loaded at 1000 via the front panel
(and verified), and a boot attempted.
When STARTed at 1000, the RUN light comes on, the RX-01
head engages (as evident from the solenoid),
That is because of the system reset. Every time you press the
buttons CTRL and INIT you reset the system and the heads will
engage / disengage (if you have the "calculator-style" keypad.
The 3-button panel version of the 11/34 has an INIT push button (?)
that shows the same behavior.
and you can hear the heads advancing a track or two
then it
stops: the "SR DISP" led and the RUN led go out, and the
display reads "005134". Examining the bootstrap area (1000)
shows the bootstrap was replaced by data.
Are you sure you hear the heads *stepping* ?
Does anyone know what the "005134" code
means?
I search through RT-11 docs and can't find anything on error
codes or such and I'm hoping this will help with the debugging.
That is not an error code but just the address where the CPU stopped.
By looking at the code you might be able to figure out what the
problem is. The RX11 (M7846) does not use DMA (NPR), so check
that the NPR wire on the backplane is present (pins CA1 - CB1) or
check that the RX11 module has connection by a trace on the
module between those 2 pins.
Thanks!
Professor Mark Csele, P.Eng.
Niagara College, Canada
300 Woodlawn Rd., L-23
Welland, ON, L3C 7L3
(905) 735-2211 x.7629
E-Mail: mcsele at niagarac.on.ca
URL: http://technology.niagarac.on.ca/people/mcsele
Author of "Fundamentals of Light Sources and Lasers", Wiley, 2004
4:38 p.m.
On 4/8/2011 1:48 AM, Henk Gooijen wrote:
You may (or may) not also have to set the switch inside the RX drive
to RX01 (non-DMA mode) vs RX02 (DMA mode). The controller
to/from drive protocol is slightly different between the two modes,
and the drive needs to know what kind of controller it is connected to.
There is also a mode switch for PDP8 (12b) vs PDP11 (8b) mode but
that one is probably already set OK.
Don
Does anyone know what the "005134" code
means?
I search through RT-11 docs and can't find anything on error
codes or such and I'm hoping this will help with the debugging.
That is not an error code but just the address where the CPU stopped.
By looking at the code you might be able to figure out what the
problem is. The RX11 (M7846) does not use DMA (NPR), so check
that the NPR wire on the backplane is present (pins CA1 - CB1) or
check that the RX11 module has connection by a trace on the
module between those 2 pins. 
4:18 a.m.
Mark Csele wrote:
I am restoring a PDP-11/34 and am currently adding an
RX-01 drive to it in order to boot RT-11.
Approximately 30 years ago, I had access to an LSI-11 with a DSD 440
which was beside a PDP-11/34 which included a Unibus controller for the
DSD 440. It was possible to boot the same floppy on both the Qbus and
Unibus systems in the same manner that you are attempting with your RX01.
However, I understand hardware far too little to help on the hardware side
of the fence. And that usually includes boot code since there is usually
only hardware ODT to help.
I have already located a copy of RT-11 on an LSI-11
system and have made a bootable RX-01 floppy (an M7946 was installed on the LSI-11 to do
this). This disk was tested on the LSI-11 system by asserting BHALT, entering a bootstrap
via ODT, and booting from the disk (which was, at the time, the only device): it boots
properly and runs RT-11 version 5.04SJ as expected.
Just in case something strange is going on, I suggest that after you boot
the RT11SJ monitor, try it again using both RT-11 commands:
BOOT RT11SJ
and
BOOT RT11SJ/FOREIGN
If both boot correctly (the second will zero the time), then your
floppy boot code is probably correct for Qbus systems. And since
(as Henk mentioned) the RX01 does not use DMA, the code used
could be identical for a Unibus system.
As additional information for below, boot code for RT-11 is:
(a) In block zero as the primary hardware boot code
(b) In blocks 2 through 5 for the secondary boot code
Block 1 contains some directory information, including volume
and owner.
Block 6 is always the start of the directory segments.
An M7846 RX-11 controller was installed in SPC slot 9
of the 11/34, the bootstrap loaded at 1000 via the front panel (and verified), and a boot
attempted.
When STARTed at 1000, the RUN light comes on, the RX-01 head engages (as evident from the
solenoid), and you can hear the heads advancing a track or two then it stops: the "SR
DISP" led and the RUN led go out, and the display reads "005134".
Examining the bootstrap area (1000) shows the bootstrap was replaced by data.
Does anyone know what the "005134" code means? I search through RT-11 docs and
can't find anything on error codes or such and I'm hoping this will help with the
debugging.
Hopefully, Henk answered your question. If you don't have a hardware
problem, then let us know and we can attempt to figure out how to use
hardware ODT to step through the code. Fortunately, with the LSI-11,
you can make up a floppy which has a HALT instruction inserted to allow
you to test the PDP-11/34 system.
Assuming that Henk's suggestion that the PDP-11/34 is displaying the
address 5134, then the boot code is using the secondary bootstrap
program in blocks 2 through 5 which were read into memory starting
at location 1000 by the primary bootstrap program in block zero.
This seems to suggest that there might be problems with the secondary
bootstrap program related to the Unibus. As far as I remember, the
primary hardware bootstrap program is always read into and executes
starting in memory location zero, then jumps (or branches) to location
1000 to execute the secondary bootstrap program. This would suggest
that execution of the primary bootstrap program was successful.
Note (as you probably already know, but others reading this thread
may not) that all addresses are in octal.
Let us know if you are successful. If you require more help, please ask.
Are you using the PDP-11 hardware for yourself or as a teaching aid?
Do you have any interest in latter versions of RT-11, especially the Y2K
compliant version? Would a Y3K compliant version of RT-11 be of
interest?
Jerome Fine
5007
days inactive
5007
days old
3 comments
4 participants
participants (4)
-
ak6dn＠mindspring.com -
henk.gooijen＠hotmail.com -
jhfinedp3k＠compsys.to -
mcsele＠niagaracollege.ca