IBM ps/2 P70 Plasma screen voltages

It would surprise me though, :) These newer displays update pixels at 25Mhz, switching a high supply voltage on and off at this rate and getting a square wave is somewhat impossible. But even if you can, the radio magnetic interference emitted from the wires would mess up any signal far beyond the display board. You want to keep any signal leads short and next to a ground plane or some other grounded leads. My board even has shielding magnets glued to the display. There's also a rather large zener diode on my board, often used for voltage stabilization by keeping the voltage at a fixed level. I tried to get it to conduct by slowly incrementing my lab power supply. It reached it's max at 30V still nothing had happened. It does give another clue though about the display needing a large stable supply voltage. Btw, that LogicDart looks like a great tool, bit expensive for a student though :( Thomas. -----Oorspronkelijk bericht----- Van: cctalk-bounces(a)classiccmp.org [mailto:cctalk-bounces@classiccmp.org] Namens Tony Duell Verzonden: zaterdag 1 mei 2004 0:47 Aan: cctalk(a)classiccmp.org Onderwerp: Re: IBM ps/2 P70 Plasma screen voltages It wouldn't suprise me either... Alas I know little about the display panel in the Integral. The rest of the machine was mostly stnadard chips (68000, TTL, DRAMs, ROM, etc) and HP parts that I had data on (1LB3 HPIL chip, Thinkjet printer chipset, etc). The only thing I had to puzzle out was the display controller, and that didn't take too long However, the display seems to be all custom chips on the back (well, there were a couple I could identify, and many more I couldn't). And because of the high voltages, I didn't want to probe around too much with the LogicDart (which has a maximum input voltage of 40V -- it's fine for a board of logic, even if there are RS232 drivers on it, but not on a plasma panel). So I indentifed the signals on the input connector and left it at that. -tony