PDP-11/44 problem - RUN stays on

Don North ak6dn at mindspring.com
Wed Nov 8 14:11:57 CST 2006

Jay West wrote:
> Perhaps your M7098 (UBI) module is set to autoboot from one of the 
> proms upon powerup, and that's why it comes up in run mode. This is a 
> personal preference thing, but I never have a machine autoboot to 
> anything other than the console emulator. I then always select the 
> boot device by hand. Many people instead set the switches on the UBI 
> to attempt a boot from a particular device upon powerup. This may be 
> why you power on in run mode. I would suggest that you look at the 10 
> position dip switch on the UBI and set 1,2, and 7 on and all the rest 
> off. Then power up and see if you dont get just the console prompt.
>> and nothing more, no ">>>" prompt anymore!
>> Also, the FAULT lamp on the RL02 drive stays ON.
> If I was to make a newbie guess... you have a problem with your RL02 
> subsystem (drive, cable, or controller) and your UBI is perhaps set to 
> autoboot the DL prom. So when you power it on it attempts to boot the 
> RL02 and hangs because of another problem. Setting the switches as 
> above would identify this possibility. If it then comes up to the 
> CONSOLE prompt correctly, you can at least know it's time to zero in 
> on the RL02 subsystem.

Even if you autoboot to run mode you should always be able to get back 
to the
console prompt by typing ^P (assuming you front panel switch is not set 
to locked).

After ^P you should get '>>>' and then be able to type 'H' to halt the 
CPU if
it is still running, and then run some basic tests 'T/E'.

If after typing ^P you still don't get >>> then something is amiss with your
console module and/or console microprocessor.

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