A mystery panel

A diagnostic panel from something.
I don't recognize any of the legends.
There is no tag, label or nameplate.

I'd love to build a microcontroller circuit to make it run again for a permanent exhibit of Das Blinkenlights!

DM160 diagnostic panel
	Front view "INTERNAL PROGRAM" SBSS BSL SBMS SBES FFW FFWA OMS OMSA OES OESA CMRA CMRB CMRC CMRD CMRE CMRF 2 of the 18 are blank: no legend
	DM160 closeup This is probably the oldest wire wrapped item I've ever seen: wire wrapped TUBES on WOOD!
	Rear view: 100K resistor for each grid, wire-wrapped directly to each post! All heaters and anodes are wired in parallel. The bare wire is daisy-chained to every post! Such lovely workmanship on the wiring harness with lacing cord.

The DM160 is a bar indicator tube, specifically designed as indicator for transistorized computers.
It is similar to magic eye tubes but it is only on or off.
There is no moving pattern like magic eye tubes
neon Flash-O-Graph, Tune-A-Lite, Tuneon
or IN-9 / IN-13 neon bargraphs.
Mullard describes the DM160 as

a special quality directly heated subminiature voltage indicator
for use in industrial equipment such as transistorised computers.

Blue-green bar lights when control grid is at zero potential.
A grid signal of 3v at 575 µA turns OFF the display (cut-off plate current and light).

anode: 50VDC at 0.5mA in on state
Filament: Vf 1 Volts / If: 0.03 Ampere / -: Direct / -: Parallel, (AC/DC)
20,000 hours life. 4-pin flying leads base.

The appeal is how it is just one part,
compared to a high voltage transistor & neon bulb
or a high current transistor & incadescent lamp.

It was popular for a short time for transistorized digital circuits because the single tube is display AND amplifier.

The British Elliott 803 computer used 6 in the center of the control panel.
(wikipedia)
The Marconi TAC (Transistorised Automatic Computer) used many
in the front panel (they call the Control Desk and Operator Panel).

For more information r-type.org has tech info (and animated images) (and detailed photos)

According to radiomuseum.org:
DM160 is Identical to 6977 and CV5412
Similar Tubes:
Other class quality (otherwise equal): CV6094:
The Russian IV-15 is SIMILAR to the DM160 but shorter and fatter as the bottom photo shows

The National Valve Museum r-type.org	radiomuseum.org
DM160 DM160 glowing DM160 animation	DM160 specs and photos
6977	6977
CV5412	CV5412
	CV6094
	Russian IV-15
	KP-125
Tuning Indicators