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Question For The DEC Brain Trust Here: Single Board Computers...

DeeAnn

DeeAnn

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Did DEC ever make a single board computer for either PDP-11 or LSI-11 hardware? I seem to have a vague memory about that, but I could be conflating that with something else...
 
I've done some research for both as I had never heard of either one. While they are SBC's, they don't run an operating system, like RSX, for example. They appear to be for running assembler applications directly or running applications under the supervision of a host computer. Is that a correct assessment?

What I was wondering was if there was if DEC did an SBC that hosted an operating system as it would seem to be a relatively simple way of getting into a runable PDP or LSI system. Beginning to look like that is not the case.

Thanks!
 
DeeAnn said:
I've done some research for both as I had never heard of either one. While they are SBC's, they don't run an operating system, like RSX, for example. They appear to be for running assembler applications directly or running applications under the supervision of a host computer. Is that a correct assessment?

What I was wondering was if there was if DEC did an SBC that hosted an operating system as it would seem to be a relatively simple way of getting into a runable PDP or LSI system. Beginning to look like that is not the case.

Thanks!
Click to expand...

Well if you want a small PDP-11 that runs an operating system like RT11 or RSTS/E or RSX11 then a system like a MicroPDP-11/53 or /73 or /83 or /93 would be something to look for.

Or at the low end a Heathkit H-11 is a small small PDP-11 based system that runs a version of RT-11.

Otherwise you are looking at a QBUS backplane, adding CPU, memory, drive interface, serial interface cards as needed.
 
Or, if you don't care about real DEC hardware per se, get SIMH and install it on a RaspberryPI and run an emulated PDP-11 on the PI. Certainly will run RSX-11 within SIMH.
 
There is a particular connection with DEC hardware due to having used PDP-11, LSI-11 and VAX machines in the past. I was hoping that there was a Q-BUS based SBC that was capable of running an operating system, but it appears not. I'll have to check into the microPDP machines.

Nothing against the Raspberry Pi's, but that would be a different project...
 
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As far as I know, the KXT-11 can definitely run RT-11. You could probably get some variants of RSX running on it as well (not sure if you'll like the experience though). But that board just gives you CPU, memory and serial port. You still need a Qbus backplane, and you need some kind of disk.

Same thing is also true for the KDJ11-E, which was in the 11/93 and 11/94. CPU, memory and serial ports are on the board. All you need to add is mass storage. And that board can run full fledged RSX-11M-PLUS. But I think it's maybe on the expensive side...
 
As an tangentially related fact (or non fact), if I remember correctly, I thought there were some DEC made or at least 3rd party SBC VAXes that were designed to run applications using VAXELN.
 
At a DECUS symposium, many years ago, the group that was responsible for the T-11 CPU chip (the Volume Semiconductors Group, I think it was) was showing off a one board system using the T-11, built into a small cabinet, battery powered, with a multi line LED display, running RT-11. They had just made a few as technology demonstrators for the T-11. if they had released it as a product, it would have sold like hotcakes.
 
AK6DN said:
Well if you want a small PDP-11 that runs an operating system like RT11 or RSTS/E or RSX11 then a system like a MicroPDP-11/53 or /73 or /83 or /93 would be something to look for.

Or at the low end a Heathkit H-11 is a small small PDP-11 based system that runs a version of RT-11.

Otherwise you are looking at a QBUS backplane, adding CPU, memory, drive interface, serial interface cards as needed.
Click to expand...

Actually, the Heath H-11 is a Q-Bus backplane with CPU, memory and interface boards. Essentially a modified PDP-11/03. It will cheerfully run "real" RT-11 if you type the boot-loader into micro-ODP.
 
>>> While they are SBC's, they don't run an operating system

That is why I was asking about what your criteria was.

My goal for my KXT11-CA is exactly that - to run RT-11 on it (using the two serial ports - one for a console and the other for an emulated TU58 tape drive as backing store). Early versions of RT-11 supported a serially-connected TU58 tape drive - but this was removed in later versions.

The only drawback I can see of the KXT11-CA is that the second serial port is not a 'DL11' lookalike - so I will have to write a modified device driver for RT-11.

Memory size is the critical thing - hence an early version of RT-11 would be required.

As far as I am aware - you do not need a QBUS backplane to run the KXT11-CA in 'stand-alone' mode. You will, however, require the QBUS connectors to supply the power.

Checkout section 1.1 of http://bitsavers.trailing-edge.com/...11/AA-5286G-TC RT-11 System Release Notes.pdf. This specifically mentions the SBC-11/21. Whether this was an 'out of the box' SBC-11/21 or not is another matter though.

Dave
 
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I was hoping for a relatively painless way of getting into the PDP-11 or LSI-11 world, but messing with boot loaders and device drivers is not in my future. The 11/53. 11/73, 11/93 approach seems quite doable, but at a price. That would require some thought on my part. While I am good at understanding and spec'ing hardware, that is about the extent of it for me. I have always avoided chip level and assembler level stuff because I never wanted to devote the effort to it.

However, thanks to all as I learned a number of things that I didn't know before!
 
Just checked the RT-11 documentation explicitly, and the SBC-11/21 and SBC-11/21 PLUS are definitely fully supported by RT-11. It's in the release notes.
But you still do need a Qbus and some disk controller.
Also, DECtape II is supported on the serial port. See the release notes.
 
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