PDP-11/84 SLU problem?

Johnny Billquist bqt at update.uu.se
Tue Dec 16 02:25:07 CST 2014

On 2014-12-15 20:40, Pete Turnbull wrote:
> On 15/12/2014 18:47, Noel Chiappa wrote:
>>> From: John Rollins it doesn't appear to transmit data from the
>>> console port on the back. I have tried ... every conceivable switch
>>> setting on the PDP with nothing
>> I asssume you've tried setting the baud rate with the switches on the
>> CPU card (in case the cable to the back panel is damaged - or, more
>> likely, the rotary baud select switch has a bad contact due to
>> corrosion over time)?
> The normal setting is all 8 switches in the pack at E83 (beside the
> LEDs) off.  Switch 1 is to do with the console SLU (see below).  2, 3
> and 4 set the boot device (all off means boot according to the settings
> in the EEPROM; all on means power up in ODT providing switch 1 is off).
>   Switch 5 is the "force dialog mode" switch - on an 11/83, setting 1
> and 5 on is used to "disable customer access to setup", to prevent the
> most common cause of the not booting correctly problem.  If switch 5 is
> on, the CPU won't go into dialog mode.  6, 7, and 8 set the baud rate,
> providing the rotary switch on the panel is either disconnected or set
> to 7 or set to 15.  For 9600 set 6 and 8 on, 7 off; for 1200 set 7 on, 6
> and 8 off.  All on is 38400; all off is 300.

If switch 5 is on, it will not go into dialog mode, true. But it will 
still print information out on the console.
Starting with the numbers printed during the memory test, and then 
information about it starting to boot from whatever.

Baud rates is, however, a very good tip.


Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol

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