26 Sep
2007
26 Sep
'07
11:26 p.m.
I forgot to mention that the B80 the firm had in Salt
Lake had an
LED display instead of a printing console. I think it was about
32x8; the sort of thing you'd see on a cash register. IIRC,
the Burroughs name for that sort of display was Self-Scan.
A Self-Scan display is not LED, it's gas-discharge (normally neon).
It works a bit like a Dekatron counter tube, in that the discharge can be
stepped from one electrode to the next by a pair of control electrodes.
Think of it as a combined shift register and display, or rather 7 or 8
shift registers (one for each row of the display) with common clock.
Basically, you apply a column of dots to the main eelectrodes at one end,
sequence the control electrodes to move it onto the next column, apply
the next column of dots, and so on until you've uilt up the pattern you want.
-tony