PiDP-11/70 Running light program

The following PDP-11 assembler program can be toggled into the front panel of the PiDP-11/70 and causes a "Running light" to be displayed on the data leds. This program is from the retrocmp.com web-site.

adress  data      opcodes	operation on switches
001000  005000    clr     r0 001002  005200    inc     r0 001004  006100    rol     r0 001006  000005    reset 001010  000775    br      001004	activate HALT data switches=001000, LOADADRS data switches=005000, DEP data switches=005200, DEP data switches=006100, DEP data switches=000005, DEP data switches=000775, DEP Start sequence: de-activate HALT data switches=001000, LOADADRS START

The upper "ADDR SLECT" knob must be in the CONS PHY position, and the lower ADDR SELECT knob must be switched to DATA PATHS.

PiDP-11/70 kit build

The PiDP-11/70 is a modern replica of the PDP-11/70. All the buttons and lights are fully functional and it uses a RaspberryPi to run original PDP-11 software and operating systems.

PiDP-11/70

The PiDP comes as a kit

Part of the PiDP-11/70 kit

Terminal connection to the PiDP-11/70 console showing the available Operating Systems to boot.

Terminal connection

The PiDP-11/70 console runs using the linux Screen utility which provides virtual terminals which you can switch between.

• Type Ctrl-a d to detech from the virtual terminal and drop back into the linux terminal
• Type sudo screen -r to reattach to the PiDP-11/70 virtual terminal. The startup screen script is run under root hence the need to run screen with sudo to re-attach. 
• Type Ctrl-a ? to view Screen help pages