• Please review our updated Terms and Rules here
  • Exhibitor application for VCF West 2022 is now open! If you are interested in exhibiting, please fill out the form here.
  • Here are the results of the VCF East 2022 Post Event Survey: Survey Results

Getting started with a minimal pdp-11/53

acollins22

Experienced Member
Joined
Mar 12, 2007
Messages
247
Location
Leicester, UK
Hello Folks,

I have just received my first ever PDP-11 and as a complete PDP newbie I'd really appreciate some clues.

It has the following cards...
M7554 - CPU
M7551 - CA - Memory
M7555 - Disk controller
M7516 - Ethernet
M7546 - TK50

Additionally the seller threw in M8043 - 4 line async. This is not fitted.

It has an RX-50 drive, console and printer ports and nothing else.

I have started it and worked through to the initial prompt. I've used "MAP" to see that it has 1.5mb of RAM and it is trying to boot off the RX-50.

I have two questions (so far :))... Can anyone point me to a floppy disk image that I can use to get it to boot into something?
Secondly. In its current state, i.e. no hard disk controller, what can I run on it?
Thirdly (I knew two questions wouldn't last). Is there an easy way to put any kind of common hard disk or flash card onto this.

I only picked this up because I'd read a little here and thought it might be fun but I can already sense my getting hooked.


Thanks very much

Andy
 

Crawford

Experienced Member
Joined
Oct 21, 2008
Messages
273
Location
Maryland
Andy,

You will also need the XXDP utilities, and you can run a tu58 emulator on a PC and attach to you second serial port (called a SLU -serial line unit) in dec-speak.
 

acollins22

Experienced Member
Joined
Mar 12, 2007
Messages
247
Location
Leicester, UK
Thanks Folks,

I'll take a look at those.

It's all still very new at the moment. I'm using an old PC as a terminal and so using it for a TU58 emulator seems to fit right it.

Until I've got a hard disk, what are my OS options?


Cheers,

Andy.
 

Crawford

Experienced Member
Joined
Oct 21, 2008
Messages
273
Location
Maryland
Andy,

I think for a floppy-based system, rt11 is the only option.

Also, check the pdp11 field guide, and find the letters after your CPU and memory, I.e. M7554-xx where xx is a sub-model. I have a m7554-sd and it has 1.5m on the CPU. YMMV

? ; - )
 

Lou - N2MIY

Veteran Member
Joined
Apr 1, 2008
Messages
1,306
Location
Albuquerque NM / Potomac MD
Andy,

The M7555 is a hard and floppy disk controller. You can use an ST506/412 interface MFM hard disk. The most reliable is likely a ST-225 if you can find one or have one around.

This is a very, very nice system to start out with. With what you have, once you have a hard disk, you will be able to use the ethernet adapter. I do suggest that you start with RT-11 as has been suggested above.

What enclosure is this system in? If you can upload a picture, it would help us. If it's a BA23 enclosure (we'll know when we see it), you'll need only two common MFM hard disk cables to get your hard disk going.

Lou
 

acollins22

Experienced Member
Joined
Mar 12, 2007
Messages
247
Location
Leicester, UK
Thanks again Folks,

I think the best way to start is probably with RT11 from TU58 emulator and then create an RX50 floppy from that (assuming that's possible - still finding my feet)

I've included a couple of photos. you can see that the standard chassis has been housed in another cab with room for drives. It also seems to have been bashed around a bit. However, it is still working.

DSCN1307.jpgDSCN1310.jpg

Cheers,

Andy
 

Lou - N2MIY

Veteran Member
Joined
Apr 1, 2008
Messages
1,306
Location
Albuquerque NM / Potomac MD
Andy,

Well, that's not what I expected for an enclosure. Where does the 50 pin ribbon cable go to in the upper chassis? It would be good if it goes to a signal distribution board with sockets for the MFM hard disk cables.

Lou
 

acollins22

Experienced Member
Joined
Mar 12, 2007
Messages
247
Location
Leicester, UK
Andy,

Well, that's not what I expected for an enclosure. Where does the 50 pin ribbon cable go to in the upper chassis? It would be good if it goes to a signal distribution board with sockets for the MFM hard disk cables.

Lou

Hehehe, Me neither. I was given another empty chassis with this but the PSU in it is unknown and I'm sticking with this one for a while as I know it works and it makes sense to limit the unknowns. (Rumsfelds?)

Here's a photo taken looking up at the distribution board fixed under the top of the chassis.
DSCN1314.jpg

The pair of socket on the front/right are duplicated on the left but are hidden behind the ribbon cable.

I'm currently waiting on another 6-25 way serial cable to sort out the TU-58 emulation.

Can I use the printer port on the casis that is directly connected to the CPU board for the TU-58? If so, what is it likely to be called?


Thanks for all of the help and suggestions, it's appreciated.


Andy.
 

gslick

Veteran Member
Joined
Dec 30, 2010
Messages
2,112
Location
Seattle, WA
That might be the standard BA23 distribution board mounted upside down.

Take a look at Figure 1-5: BA23 Signal Distribution Panel on page 1-8 of this manual:
http://www.bitsavers.org/scandocs.t...pdp11-volume_2_enclosures-EK-186AA-MG-001.pdf

The 50-pin cable would be connected to the M7555 RQDX3 and the 34-pin cable below it would be connected to the RX50 (you could also use an RX33 there). The 10-pin and 34-pin connectors to the right are where the hard drive(s) would connect.

-Glen
 

acollins22

Experienced Member
Joined
Mar 12, 2007
Messages
247
Location
Leicester, UK
I'm on the look out for a suitable MFM drive as suggested. That would really open the doors.

In the mean time I've sorted out a PC to use as a termainal and also a TU-58 drive. My PDP has 2 serial ports, one is labelled Console the other "printer". Is it possible to get the bootloader to think that my PC connected to the printer port is a TU-58? If so, when I ask it to boot, how do I specify the printer port?

Thanks,

Andy.
 

gslick

Veteran Member
Joined
Dec 30, 2010
Messages
2,112
Location
Seattle, WA
Did you download the manual yet for the M7554?

KDJ11-D/S CPU Module User's Guide - EK-KDJ1D-UG-002
http://www.bitsavers.org/pdf/dec/pdp11/1173/EK-KDJ1D-UG_KDJ11-D_May87.pdf

SLU 0 (Console Serial Line Unit 0) is fixed at 17777560
SLU 1 (General Purpose Serial Line Unit 1) is fixed at 17776500

The baud rate for SLU 0 is set by jumpers W4, W6, W9
The baud rate for SLU 1 is set by jumpers W10, W7, W12

The baud rate can also be set through whatever you have connected to the 34-pin connector J1. Any jumpers or switches on the external connector panel should just be wired in parallel with the buad rate jumpers on the M7554 board.

The M7554 manual lists DD0 or DD1 as available boot choices for TU58 devices. I have never tried booting from a TU58 device myself on my M7554 CPU. I assume it should just work if you have the device connected to SLU 1 and the baud rate configured the same between the CPU and the device.

-Glen
 

Marty

Veteran Member
Joined
Jul 26, 2009
Messages
3,116
Location
Boulder , Colorado USA
Hi All;
ACollins22, ""Is it possible to get the bootloader to think that my PC connected to the printer port is a TU-58? If so, when I ask it to boot, how do I specify the printer port?""
As Long as two thing are set up for what You need..
First, Check that Your PC Printer Port ISN'T a Parallel Port.. And

Second that IF it is Indeed a Serial Port the make Sure that the appropriate Signal lines are there.. RX, TX and Ground..
Most, but not all Pc's have a DB-25 along with one or two Db-9 connectors..

THE DB-25 most of the Time is Parallel Port and You Do Not want to use it..

I have seen Some Old PC's that Enable You to set it up for either Parallel or Serial port, but that IS RARE !!!
The DB-9 are the Serial Port(s)..

If Your PC Does have Only One Serial port and One Parallel Port, then You have a possibility of a couple of choices..
If the PS has USB then You could get a USB to Serial Converter and Use that at for Your PDP Console Port instead of the One Serial port that you have and use the one serial port for the TU58 Emulator..
The other possibility is to get a Parallel port to Serial Port Converter and again use that for the PDP Console port..
But I would Not recommend using either one of these options for the TU58 port from what I have been told by the Experts..
THANK YOU Marty
 
Last edited:

acollins22

Experienced Member
Joined
Mar 12, 2007
Messages
247
Location
Leicester, UK
Woo Hooo it's working :)

Thanks to gslick, Crawford, Lou - N2MIY and Marty I have now successfully booted my PDP-11/53 from a PC running Don's tu58em into XXDP

For those that follow and are as new to PDPs as me, this is what I did.

Downloaded the TU58 emulator from Don's site here. This enables a PC to emulate a TU58 which is a tape drive unit that talks to the PDP using a serial port.
I downloaded a disk image for the TU58 emulator to load and present to the PDP when asked, from here.

I used Win Xp on my rather old laptop and used Hyperterm on COM1 (19200) to act as my terminal to the PDP.
I started a command prompt on Xp and then started tu58em with the options -p5 -s 9600 -r 11xxdp.dsk. This starts tu58em talking on COM5 at 9600 baud with the disk image mounted as read only.

I had COM1 connected to the console port and COM5 to the printer port.

I started the PDP, watched it go thorough its self test and the numbers 1 to 9 and when it started rattling the RX50 I pressed ctrl-C to break the boot. It asked for a command and I used...
Code:
BOOT DD0
and watched as it started up.

One point I didn't pick up on until I saw it was that it has both DD0 and DD1 are on the same port. I thought they would be on two serial lines (SLU) and they are not :)

Now I've booted up the PDP I'll sit down with the manuals and boot myself.


Thanks again folks. Much appreciated.


Andy.
 

gslick

Veteran Member
Joined
Dec 30, 2010
Messages
2,112
Location
Seattle, WA
Nice work. It's always a good idea to make notes as you go along. I don't tinker with my systems often enough to remember all of the details so I write down hints to remind myself where I downloaded manuals and binaries, and magic commands and configuration details necessary to make things work.

Did you already find the XXDP manauls?
http://www.bitsavers.org/pdf/dec/pdp11/xxdp/PDP11_DiagnosticHandbook_1988.pdf

You probably want to start by running the 11/53 diagnostic OKDDD0.
Then run the Q-Bus memory test VMSAC0.

-Glen
 

Crawford

Experienced Member
Joined
Oct 21, 2008
Messages
273
Location
Maryland
Andy,

Good on ya mate!

I would send you one of my spare MFM disks but shipping would be fairly dear, and they may not survive international shipping.

But it's running !!!


? ; - )
 

Lou - N2MIY

Veteran Member
Joined
Apr 1, 2008
Messages
1,306
Location
Albuquerque NM / Potomac MD
Congratulations Andy! You have made very quick progress!

The machine probably seems slow now, but that is because of the slow serial connection to the TU58. When you have an MFM disk, it will be much faster. Even then, the M7555 and MFM disk will still be slower than what your 11/53 can support. Maximum speed would come from a SCSI adapter (which you don't have yet) and a scsi disk. But, take one step at a time and find that MFM hard disk. There should be plenty on your side of the pond, you just have to put the word out that you are looking for one.

I'd also suggest that you look for a dedicated terminal (VT100/220/320/420/520 or 525). There should be plenty of those too.

Lou
 
Top