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Fun project "LSIbox": front-end processor for PDP-11

J

Joerg Hoppe

Experienced Member
Joined
Nov 10, 2014
Messages
112
Location
Goettingen, Germany
Guys,
This is a typical "look what I did" posting:

"LSIbox" is a micro-Linux system used as front-end processor for a QBUS PDP-11.
Core is a BeagleBone with 4 UARTs and GPIOs, connected to H9270 backplane.

You can remote control the front panel,
download code and start it over ODT console,
run terminal and PDP-11 emulations,
operate the PDP-11 "driveless" with TU58 emulator or SCSI2ID,
or use the box as a small Debian-PC.

Everything is packed in a small DEC-style box, making a stylish outfit was most work.

See retrocmp.com/projects/lsibox + sub pages

Took half a year to complete, perhaps waste of time?

best,
Joerg
 
If you wrote a bootloader and an RK05 driver for RT11 you could use Serialdisk as an RK05 disk emulator on one of the serial ports.
 
Ok, call me stupid and not trying to take away from all the work you did but what’s the difference from that and just running PDP-11GUI on a separate system to control the hardware? Wonder what the problems would be in building up an interface that allows you to have direct access to the data and address bus along with a bunch of switches to manually enter values? What you would have then is a Unibus style control panel on a Qbus system. I know that the 11/34 control panel has the KY11-LB card that allows you access to those functions and would wonder how difficult it would be to build up something like that? This way we would have a Unibus style control panel with switches and lights without the Unibus price.
I have been wasting hundreds of hours in the last couple years doing work on Nova systems in machine language using direct toggle in entry and debugging in binary and have to say that if you’re doing simple stuff there is no substitute for direct entry.
 
Qbus said:
Ok, call me stupid and not trying to take away from all the work you did but what’s the difference from that and just running PDP-11GUI on a separate system to control the hardware?
Click to expand...
Hmm, forget to tell that this project was mainly about having a BA23-mini-case with the QBUS cards exposed on top.
Surely no need to build it just to have a debugging environment ...

Wonder what the problems would be in building up an interface that allows you to have direct access to the data and address bus along with a bunch of switches to manually enter values? What you would have then is a Unibus style control panel on a Qbus system.
Click to expand...
So the idea ist: use a BeagleBone or RPI and connect GPIOs to all QBUS pins, to have a direct bus access?
Then construct a lamp&switch panel which is controlled by even more GPIOs?

Joerg
 
Not that smart of a guy to do it myself but was thinking of something like a PLC that has lots of GPI/O available, would need about 24 GPI inputs with having 16 for address or data, another switch for selecting the switch bank for address mode and data mode, about the same number of lights for the data / address bus, run, power and fault. Would not be like a full blown Unibus system and more like what you get with a 11/05 where they share the same switches and display. The PLC can be set up to send the commands to the system via the CON port, the echo back from the CON would be used to drive the address/data display. Maybe have a GPI for “Boot” option also. The KY11-LB has a 8085 or something like that along with its octal keyboard and display and have thought of looking at the code for that but that’s like project 8,456 and I am still trying to get project 3 completed.
Your case and fabrication work is all first rate and indeed a thing of beauty. Like the tower alongside for air circulation.
 
The KY11-LB has a 8085 or something like that along with its octal keyboard and display and have thought of looking at the code for that
Click to expand...
Forget about the KY11-LB as example. The CPU is 8008, and the board is full of TTL chips, the 8008 is interfacing to these and not to the bus.
See http://retrocmp.com/tools/pdp-1134-programmers-console for a picture.

But wait: there are QBUS-UNIBUS converter cards (ABLE QNIVERTER), so that + KY11 = your QBUS console ?

but that’s like project 8,456 and I am still trying to get project 3 completed.
Click to expand...
Same here!
 
NeXT said:
Not really sure about that cooling solution....
Click to expand...
Wasn't working first, until I used a 180m³/h fan and integrated bundles of little blow pipes.
Now airflow is very focused, can blow off a pocket lighter one foot away.
Good cooling if pointed carefully to the card cage.
 
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