Display technology? (old laptop)

They were marketed as plasma, as best I recall (way out of my reach at the time, but I did see a few). An array of tiny neon bulbs, conceptually, or something close to that.

I think that's right. I had an IBM PS/2 Model 70 Portable (25 MHz 486, very swish at the time) with an orange plasma display. It was a sealed glass panel filled with low-pressure gas and it used electrodes to strike a plasma--exactly like an array of very small NE-2s in one envelope. It was definitely less purple-pink than a plain Ar/Ne glow, so they must have put some helium or something in there as well.

Cheers,

Phil Hobbs

Must been this one (IBM PS/2 Model 8573-P70 8573-121):

Seems someone figured out how to controll them aswell:

Guess an FPGA and 5V level translation should enable one run the screen without the computer :)

I've seen some greyscale displays from this era aswell. Any idea how they work?

Now that I think about it, I think it was a Model P75--same thing but with a 486DX. It looked exactly like the one in the pictures...weighed probably 25 pounds. Running DOS and DesqView (a full-screen DOS task switcher that I just loved), it was great stuff for 1990.

Cheers,

Phil Hobbs

Those are all LCD screens.

The Plasma screens were limited to about 16 intensity levels, mainly because the dot could not be completely extinquished. The display was self-scanning, at one end of a row a dot was created, then transported using much like the charge in a modern CCD. By modulating the current the light output was controlled.

I designed some medical equipment in those days using Burroughs "self-scan" plasma displays, they needed AFAIR a hefty 200V dc at almost 100W if fully lit. A 4-phase clock transported the dot. For the principle see

Arie de Muynck