DECbox - how to operate

Parent Category: Projects Category: DECbox Written by Administrator

Look and feel of the DECbox installation

After powering on, the user is greeted by an intro screen, presenting the "DECbox" as an advanced secret research prototype of Digital Equipment Corporation.

decbox screen intro
Note the bureaucratic organisation and the loss of some civil rights if you proceed (as soon as you get tired by this joke, you can replaced the intro screen with some other text).

After pressing  "Enter", the main menu appears. Here you selected the SimH installation to run. An installation is a special hardware/software combination.

decbox screen menu

For the selected installation, you can navigate to "Help" and get some explanation what you see and what you can do after start.

decbox screen help

After selection of a machine and pressing the Enter key, the simulation starts immediately.

You see the hardware boot, or you must manually select a boot device first. You will not know what to do next, unless you've read the Help file.

decbox simh 211bsd boot

Booting and operating the installation can be quite slow. Whenever possible the execution speed of the simulation was throttled down to the original speed. So there may be long pauses where apparently nothing happens ... be patient, as it was necessary in the old days!

decbox simh 211bsd login

For user accounts and passwords check again the help file. Then start exploring!

Here I go into the Internet with my PDP-11/44 under 2.11BSD Unix:

decbox simh 211bsd ftp

Yes, this is my own ftp server. Now guess some of my hobbies ...

After running the installation, you should shutdown the installation with the original procedure. This is extremly important for those old Unixes ... their file systems get damaged, if you simply power off.  DEC operating systems are more robust.

decbox simh 211bsd halt

After the simulated machine stops, you leave the simulation by pressing "Ctrl-E". You return to the "sim>" prompt, there you press "q". And then you log out the Linux session by pressing "Ctrl-D".

 

Adding more terminals for multi-user demos

The BeagleBone inside the DECbox has four serial RS232 interfaces, three DSUB9 plugs are accessible at the rear side. All those ports are configured for interactive Linux login sessions. So additional terminals can be connected (all 9600 baud), and DECbox can run several installations in parallel on different terminals.

decbox vt100+vt220

 However, a particular instlalation can only be run by one user at a time.

Adding more SimH installations

DECbox is meant as open system:  it lives from contributions by experienced SimH users. Invite them to to provide their own installations!

The amount of emulated machines is only limited by SimH's capabilities and your imagination ... some 20 to 30 different installations should be possible. The size of the microSD card is barely a limit for all those small old disk and tape images. If space really becomes an issue, the 8GB card can be replaced by a 32GB model.

Network clusters

The simulated DEC machines have simulated network adapters (DEQNAs and DEUNAs). As first gimick, I made two microVAx installations under VMS 5, which both have their DECnet properly configured.

If two DECbox users run both microVAXes in parallel, they can share files between these two "VAXes" over virtual DECnet, even with real VAXes connected to the outside Ethernet.
So DECbox could be configured as a VMScluster ... a "VMScluster in-a-box"!

decbox 2 vaxes

 

Tips to make the most of the presention

1. The biggest barrier for users operating the DECbox is the lack of knowledge how to operate those ancient operating systems.

2.  Even experienced computer people get overwhelmed by the contrast of the tiny BeagleBone and the amount of virtual machines it can simulate in parallel. Support this experience:

microsdcard ra81 total
I contrast the SD card to an DEC RA81 disk drive: made in 1980, size 456 MB, weight 67kg, consumes 640 watts.

The microSD card is made in 2011, has 8GB, and weigths 1/2 gram.

microsdcard ra81 close