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Starting uPDP-11/73 in boot dialog mode

M

MattCarp

Experienced Member
Joined
Sep 5, 2003
Messages
279
Location
Atlanta, Georgia (USA)
I have my MicroPDP-11/73 set to autoboot an RQDX3, which works fine.

I installed an Emulex UC07 and prepared a SCSI disk with RSX-11M 4.6+. I'd like to prevent the autoboot of the RQDX3, and, manually force the boot of the SCSI disk.

Is there I can interrupt the booting without changing the autoboot jumper/configuration? I seem to remember being able to get into the boot dialog (Help, Boot, List, Setup, Map, Test) - maybe that's when I had problems with my disk drives?

I did a map at one point, so I know my CSR address of my UC07. So, I'm thinking I should be able to enter a command like:

B DU /A
Address = 17 7xx xxx

with xx xxx being whatever the UC07 address is?

Forgive me, I'm learning the PDP-11. If you have any tips on where to go to learn, I'd also appreciate. I have all the manuals, but it seems there should be a decent tutorial somewhere.

-Matt
 
There should be a switch on the top of the 11/73 card to set or unset autoboot. Was not able to find a switch detail list, but I know someone here will have it.
 
Why not? Just jot down the current setting and then change the one to not auto-boot. I do not know if there is a way around auto-booting without changing that switch.
 
Do you have the standard KDJ11-B SLU display panel with the DB-25 console connector, dual 7-segment display, and rotary baud rate switch? If the baud rate switch is set between 0 and 7, add 8 to the switch setting to select dialog mode.

KDJ11-B_SLU_Display_Panel.png
 
Thank you Glenn. So you’re saying that the switch can select positions 8 to 15?

sadly, I don’t have the right cab kit…. So I suppose I need to use the jumper/switch on the processor board.

why would I prefer an external setting? Easy- the thing is about 50 pounds, and is fully put together, sitting on carpet next to my bench. It’s a real pain to pull it out to set this setting. The SLU panel would be more convenient.
 
KDJ11-B CPU Module User's Guide, EK-KDJ1B-UG-001
Page 2-3 (Page 70 of the PDF)
2.2.2 Switchpack, Figure 2-2 Pin Assignments for Connectors J2 and J3

The KDJ11-B switchpack positions 6, 7, and 8 which set the console baud rate, and position 5 which selects Dialog mode are wired in parallel with pins on connector J2. If you don't have the console SLU panel and just have a console cable plugged into J1, you could make up some sort of simple cable that plugs into J2 for remote control of the baudrate and Dialog mode switches, or just a cable that has a single switch for Dialog mode if that is the only thing you need to easily change without removing the CPU board.

KDJ11-B_Switchpack.png
 
Thank you for pointing me to this reference!

Also, I found on page 2-10 that I can press ctrl-p or ctrl-c during startup self-test.

I really need to study this manual closely!
 
MattCarp said:
sadly, I don’t have the right cab kit…. So I suppose I need to use the jumper/switch on the processor board.
Click to expand...

It's not cheap, but you can get one with the cables from Keyways in Ohio. I just bought one. The price was $100 plus shipping. I bought mine along with a DEC Vt Lan40 terminal so the shipping was included with the terminal price. Write to sales@keyways.com. Mitch Miller will reply to you.
 
My 11/84 has a similar but different cab kit. It's a 10 position rotary switch with an on/off for forced dialog mode. I guess I never fully understood back then when I ogt it what that did. Is that the cab kit you may have?
 
MattCarp said:
Thank you Glenn. So you’re saying that the switch can select positions 8 to 15?

sadly, I don’t have the right cab kit…. So I suppose I need to use the jumper/switch on the processor board.

why would I prefer an external setting? Easy- the thing is about 50 pounds, and is fully put together, sitting on carpet next to my bench. It’s a real pain to pull it out to set this setting. The SLU panel would be more convenient.
Click to expand...
Ah, now I understand. I have my 11/84 on a furniture dolly. I can no longer easily lift it myself. Bad back and old age.
 
Yes, locating all of the relevant documentation (mainly on bitsavers) would be the first action - then give it a read.

Yes, hitting ^C should get you into dialogue mode.

Within dialogue mode you can adjust the priority of the device boot order and save to EEPROM. This would be the default order and the processor tries each device in turn.

I used to take the first boot device offline if I didn't want to boot RSX11M+ and the CPU would attempt to boot from the next device and so on - until it couldn't boot where it entered dialogue mode (if I remember correctly). See the SETUP option.

The boot order can switch from one controller to another if you like.

See pages 4-8 and 4-9 of the manual referred to in post #10.

Dave
 
Last edited:
Excellent- thank you Dave.

I do have the processor handbook (hard copy!), and of course now the technical manual. I previously downloaded all 8 volumes of PDFs for RSX-11M 4.6.

[perhaps a new thread]
Is there any other reference I should not overlook? My goal is to be able to get to know the PDP. Maybe compile and run a program.
 
>>> (hard copy!).

Wow, real paper to scribble your notes on!

What computer languages do you know and fancy using with your set-up?

Of course, you need ADVENT - and the games disk...

Dave
 
Thank you for asking- I studied comp sci at Ohio State from 1987-1992.. it was fun in that only the first course required a specific language (Modula-2!). Beyond that, my strategy was to pick the most suitable tool for the course, and try to diversify as much as possible.

Since then, my career involved programming business systems, but 10 years ago I moved into automation. I’ve realized that 3rd generation high level languages are all about the same. They all have conditional, assignments/operators, looping, variables & data types, and libraries to actually do stuff.

As far as applications…I think I’ll start with making it a simple file server! I haven’t thought that far, so we’ll see.
 
I used to work for the CEGB (Central Electricity Generating Board) in the UK. I now work for one of the Privatised industries arising from the break up of the CEGB.

We had our own control and display computer languages (CUTLASS and SWEPSPEED) both running on everything from a tiny LSI-11 to a large 11/73.

I am hoping to persuade the "powers that be" to release the code and documentation for one (or both) of these into the 'enthusiast' arena.

Dave
 
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