PDP 11/73 is ALIVE!

From: Ian Primus <ian_primus_at_yahoo.com>
Date: Sun Nov 23 12:56:55 2003

On Sunday, November 23, 2003, at 01:10 PM, John Allain wrote:

> Guaranteed there is someone on the list that is an active
> 11/73 user. I want to be one, but I'm not there yet.
>
>> Powering it up gives me the _at_ prompt.
>
> Look for your KDJ11 manual**, chapter 3, for ODT. That's
> the lanuage thats expected over your serial line (Working?
> Congratulatations! BTW).

Thanks. It was really cool to see that prompt... I had been trying to
plug the terminal into channel 0 on the card, figuring that the console
would need to be on the first port, but then I found the information in
the interfaces handbook, and found that it needed to be on channel 3,
and I also was able to read the wire jumpers, and figure out how the
board was configured.
>
>> I have a tape boot program here, on a piece of paper,
>> but I don't know how to type in the values.
>
> What does it look like? Numbers, Mnemonics? How many lines?
>
Here is the boot program I'm trying to use:

Memory Location Content Macro Instructions
--------------- ------- ------------------
2000 5000 Start: CLR R0
2002 5300 5$: DEC R0
2004 1376 BME 5$
2006 12706 MOV #1070,SP
2010 1070
2012 12701 MOV #172522,R1
2014 172522
2016 12702 MOV #100001,R2
2020 100001
2022 10211 MOV R2,(R1)
2024 10211 MOV R2,(R1)
2026 22711 10$: CMP #122204,(R1)
2030 122204
2032 01375 BNE 10$
2034 12704 MOV #MESS+20.R4
2036 2062
2040 05007 CLR PC
2042 46523 MESS: .WORD 46523
                                00001 .END

I am not even sure that this is meant for this particular computer, or
this tape controller. I also am confused by the last command, since it
doesn't have a memory location. Thanks to some help from Fred N. van
Kempen, I was able to type it in (I have to type <memory
location>/<contents> - before I was trying to type them in separated by
a space). After I typed in the program, I typed 2000G, and it just
hung, the RUN light on. Pressing Break on the terminal stopped it, and
it printed 2026 on the screen. While the program is running, the LED on
the tape controller is lit, but the tape drive doesn't spin or do
anything. (And yes, I do have a bootable tape loaded, and the tape
drive set to online). I don't know for sure that I have the tape drive
connected right though.

> Also look around for any ROMS not on the SMD,Pertec controllers.
> These could contain a bootstrap you can activate. Write down any
> information that may be pasted on these ROMs. It's also possible
> the controllers' ROMS can start a CPU bootstrap directly too.
> In any case, Your supplier, Wayne was a turn-key systems VAR
> (value added reseller). I would almost expect your system to be
> a turn-key one right now.

If I don't type the program in, and just turn on the system and flip
the Boot switch, the LED on the tape controller flashes briefly. I
don't see any ROMS, there is an empty socket on the CPU card where a
ROM might be able to go, and the ROMS on the tape controller are
factory made (not EPROMS that may have been added later) Maybe I should
install the hard disk controller? Right now it just has the CPU card,
serial card, RAM card and the tape controller in it. What other
configurations do I need to do to get it to recognize the drive
controller? From what I have been able to tell, in the PDP-11, the
order of the cards matters, and their addresses need to be set
manually, right? How to do this, I'm not sure.

>
> Last weekend was a big breakthrough. In less that 24 hours you
> amassed a total system that I have spent many weeks over a
> period of many years collecting. Wow! Another BTW, these
> systems used to be sold for $85,000 each!

Yeah, I really love this system, and I'm really glad I was able to get
it. I've got a lot to learn about it, but I'm really looking forward to
getting it booting and running something. I haven't decided what OS I
want to run on this thing though, I have the boot tape for RSX, but it
should also be able to run RT11 and UNIX. Any others? What other
software is available?

Thanks!

Ian Primus
ian_primus_at_yahoo.com
Received on Sun Nov 23 2003 - 12:56:55 GMT