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PDP 11/73 in BA213 Cabinet Error

SteveG

SteveG

Experienced Member
Joined
Sep 30, 2020
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151
Location
Millmeece Near Stafford UK
When powering on my KDJ11 - SC PDP 11/73 CPU in a BA213 cabinet the CPU sits with “0” displayed on the CPU (see photo).

I have set the jumper settings in the CPU for 9600 Baud rate and BOOT options are set for an interactive console BOOT.

Nothing appears on the console even after typing CTRL <C> and the CPU does not appear to cycle through any tests.

The CPU is installed in slot 1.

Any ideas?
 

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A code of 0 can mean a number of things:

HALT switch ON.
CPU fault.
Power Supply fault.

What state is your HALT switch in?

I see you have the terminal plugged into A1. How do you know this is the console and not A2 (out of interest).

I have just been playing with some MicroVAX 3100 desktop machines and I am convinced that I read to connect the console terminal to port 1. It turns out that it is port 3 (for both machines). Either the documentation is incorrect (or for a different machine) or these machines are wired wrong? I could have misread the documentation of course!

Dave
 
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In the documentation and on the front panel they are identified as SLU0 and SLU1 Just to complicate matters.

I have tried both ports and also removed and inserted the red lock key in SLU1 to SLU0.

The location of the HALT jumper is not obvious as my CPU is not the same layout as the documentation (see photos below):-
 

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daver2 said:
A code of 0 can mean a number of things:

HALT switch ON.
CPU fault.
Power Supply fault.

What state is your HALT switch in?

I see you have the terminal plugged into A1. How do you know this is the console and not A2 (out of interest).

I have just been playing with some MicroVAX 3100 desktop machines and I am convinced that I read to connect the console terminal to port 1. It turns out that it is port 3 (for both machines). Either the documentation is incorrect (or for a different machine) or these machines are wired wrong? I could have misread the documentation of course!

Dave
Click to expand...
Dave,
On the back of a MicroVax is a "Break/Enable" Switch and LED - When the break/enable switch is in the up position, MMJ port 3 becomes the console port
and you can halt the system by pressing the break key. In this up position the LED is on. In the down position MMJ port 0 becomes the console and the LED is off.
This is from page 1-3 of the MicroVax model 40 and 80 manual but I believe this applies to other models as well.

Best,
Mark
 
SteveG said:
I have set the jumper settings in the CPU for 9600 Baud rate and BOOT options are set for an interactive console BOOT.
Click to expand...

In your photo it appears that you have jumper W22 removed, which is the autoboot setting. To enter console mode instead, install jumper W22. I just took a look at my M7554-SD board that I had installed in a BA215 and I have jumper W22 installed.

KDJ11-D/S CPU Module User's Guide, EK-KDJ1D-UG-002

Page 2-2, Figure 2-1, KDJ11-D/S Module (M7554)
Page 2-4, Table 2-1 Jumpers
Page 2-8, Table 2-2 Boot Select Options

You might also want to remove jumper W11 to enable console break, so sending a break should drop into ODT. I have jumper W11 removed on my M7554-SD board.

If you move the W11 jumper on your board to the W22 jumper you would have the same jumper settings on your board that I do on mine.
 
Gslik,

GOOD NEWS

Thanks for your advice. The link you sent gives the correct board layout.

BAD NEWS

I still see nothing on the console VT220 after making the changes you recommended (NB. I had already removed the W11 jumper).

This CPU should be in the far right slot of the BA213 slot 0/1. Is my assumption correct?

Thanks
 
Just thinking out of the box - the VT220 is set for DEC423 connections and does actually work doesn't it? Have you tried it with an external loopback?

Dave
 
To make sure it’s not the VT220 I tested it on a MicroVAX cosole set to 9600 and it worked on that ; NB. i just moved the leads across.

I assume that the LED’s on the front panel should read 9 8 7 6 5 4 3 2 1 after re-boot as each test is completed.
 
That's good.

If I remember correctly, there is a little rotary switch behind the front metal panel that is used to select the console baudrate. Is that set to 9600?

Dave
 
There are links on the board for the baudrate. But the signals are also brought out to the connector that interfaces to the front panel and there is probably the rotary switch on the rear side of it... Have you removed the card and checked?

Dave
 
daver2 said:
There are links on the board for the baudrate. But the signals are also brought out to the connector that interfaces to the front panel and there is probably the rotary switch on the rear side of it... Have you removed the card and checked?

Dave
Click to expand...

The 16-position rotary switch is wired in parallel with the boot select jumpers W2, W3, W5, and W8. To use the rotary switch, jumpers W2, W3, W5, and W8 should not be installed, which is the factory default setting.
 
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