• Please review our updated Terms and Rules here

SMS11X PDP11

Ragnarock

Ragnarock

Experienced Member
Joined
Sep 15, 2017
Messages
197
Location
Texas
Help, I have an SMS 11X PDP11 system.
Restored the hardware to the best of my ability.
It has an 8" HD that wont boot but the 8" FD will boot diagnostics.
I've tried a bunch of other "RT11" RX01 disks (SSSD) and it just halts.
What I need is tech info on this system because it has some special boards in it.
16-slot QBus backplane made by SMS
1 M8186 KDF11-A CPU board with 1 chip LSI 11/23
2 SMS disk controller cabled to another giant disk board then to HD and floppy. SMS zC2M
3 Sigma quad serial (1st port displays boot prompt)
4 Sigma quad serial
5 Kaiser & Damm, MOT 11 D1 with ribbon cable to, RAM and ROM, 6809, ROMs. CALMOT '83
6 Kaiser & Damm, MM07 (memory management?) 11.Aug.83
7-14 Unused
15-16 Camintonn CMV1000 memory board (probably 1mb)
I made a web page to describe it.
Looking for advice on how to boot RT11.
I suspect I just need the right media.
Or is the 1M memory board in the wrong place or something.

RogerArrick.com/sms11x
 
What is an SMS 11x PDP-11? Got some pictures for us folk not knowing what this is? What kind of HD?
 
Hi, Realistically - your route to making this run RT-11 so you can do some development, is to dispense with the custom boards you don't need, keeping the CPU, memory, serial lines, floppy controller in the existing chassis - and add a SCSI card and ZuluSCSI to SD card as the hard disk...

Then you can boot RT-11 over a second PDP-11 serial port from a TU58 emulation on a PC, and initialise the SD-Card hard disk and make it bootable...

Using the original hard disk is likely to be uphill work and when it fails, you are back to the above plan...

You have the hard to find chassis and backplane, other parts can be non-DEC and work perfectly for what you need. Real floppy drives are a nice bonus as well.

This is basically how I got my DEC compatible system up and going.

Robin
 
While in general I agree with Robin, I'd take a look at the documentation for the SMS 1000 (1978, so a later product than yours) for somewhat relevant information. Supports the same two processors and uses the same Clearpoint memory module.

IMO a better bang-for-buck would forgo looking to acquire an expen$ive SCSI controller, instead investing in a RQDX3 controller (common and inexpensive) with David Gesswein's MFM emulator (
) and then spend the saved $$ instead to add the missing KTF11-AA (Memory Management Unit) and KEF11-AA (Floating Point microcode ROM) to your M8186.
 
Yep - that's an option as well, there are some cheaper SCSI cards around, if you're lucky, like the Viking QDD/QDO/QDT and the Viking QDT Tape controller can usually be converted to a disk controller - the ZuluSCSI lets you have up to 7 disks online and bootable as well, so useful for having a disk to run sysgens from and a different normal boot disk, as well as many extra non-bootable partitions for data etc.. (using the extended DU device addressing for up to 64 drives)

The MFM emulator and RQDX3 option would be cheaper - and you will also need a suitable bootstrap board if your disk controller doesn't have onboard bootstrap option...
Look down this thread:

 
Last edited:
I'm not concerned with the HD now, it's likely toast. What I'd like to do is make this RX01 floppy drive boot RT11.

I know this drive is good and its controller, I can boot DYDPT diagnostics,
this means a lot works - drive, controller, power, CPU, Serial I/O, at least some RAM. I'm very close.

I think it's this strange board configuration and media issue.
Do you have a board configuration suggestion? It's currently

0 M8186 KDF11-A CPU board with 1 chip LSI 11/23 top, bottom
1 SMS disk controller cabled to another giant disk board then to HD and floppy. SMS zC2M
2 Sigma quad serial (1st port displays boot prompt)
3 Sigma quad serial
4 Kaiser & Damm, MOT 11 D1 with ribbon cable to RS232 port, has RAM and ROM, 6809, ROMs. CALMOT '83
6 Kaiser & Damm, MM07 (memory management?) 11.Aug.83
14-15 Camintonn CMV1000 memory board (1mb)
 
Hi, Make sure you photograph and document how it is at present before you start, lol - some photos of the card cage and backplane would help as well - and the front panel switches... a real PDP would have Power, Halt/run and reset and maybe a LTC (clock) switch

Remove the Kaiser and Damm cards and store in anti-static bags, put the memory in the first free slot - the slot order depends on the backplane, if all your boards are "left justified" then keep them like that.

You will need to be able to halt the processor to get the "@" prompt to key in a bootstrap to boot over the serial port, from TU58FS or similar:

TU58FS - Overview

Joomla! - dynamische Portal-Engine und Content-Management-System
retrocmp.com retrocmp.com

Then you can boot RT-11 from a virtual tape over the serial port (likely the connector on the other serial card at the opposite end) and format and make a bootable floppy...

You can do very basic stuff booted from a floppy - writing software would be far too tedious

Do you have docs for the serial cards? You need to find the port at 176500 for the TU58 connection... Your console port is at 177560
 
..Oh there is a way to get TU58FS to enter the bootstrap for you using the console port - but I've not done it that way...
 
Pictures are on my web page along with each board, but I'll post a couple here:
sms11x.jpgIMG_5674.JPG
 
Ah OK - so it has a serpentine card arrangement - it is upside-down in the photo, you can have a gap to memory or bootstrap cards, generally speaking.

Do you have the docs for the sigma serial ports or disk controller? Photos of the board with red handles and the disk controller would help...

Use anti-static precautions handling the boards - store in anti-static bags if out of the system
 
This disk system is suppose to emulate both RX01 and RX02 according to brochures. Should be transparent to software.
 
OK - so it looks like the disk controller board is just bus logic to interface to the big board... pretty unusual... and that your CPU has no MMU installed, limiting you to 56KB out of 64KB, regardless of memory board installed.

RT-11BL or SJ will run OK in 56KB (28KW) so worry about that later...
 
I would have a read up on TU58FS - use the port labelled "0"on the other serial card - start with trying it at 9600, it will be slow, but you're looking for working - not fast at this point... and a TU58 is never fast...

You will need suitable double density disks to initialise when you get that far... Use RX02 (DY) rather than RX01 (DX) for 256KB rather than 128KB per disk
 
Hmm, ok, let me think about what you said on the serial. Since I got ODT and diagnostics to appear at the port I'm using, I thought I was on the correct port for RT11 to boot.
 
There is a memory management board in this system from what I can tell, this board, and possibly the one next to it.

IMG_5654_1000.jpg
 
I have an operating DOS-based imagedisk system with 8" double sided drives and a controller that will write all densities.
I wonder if I can write RX02 disks with that?
My understanding is that it is single density on track 1 and double on others.
 
Hi,
You have the correct port for the console - no 7, the TU58 connects to port 0 and then to a PC running the TU58FS software, so you can control the PDP from the console and tell it to boot from a tape device (emulation) on the other port
 
The MMU should be a 40 pin chip on the processor board that looks like the CPU but in the end socket... I'm not saying that can't be memory management... but it's not what you would expect!
 
You must log in or register to reply here.
Back
Top