On Mar 19, 2013, at 4:44 PM, Chuck Guzis <cclist at sydex.com> wrote: When I said "operator", I guess I meant a simple gate, like an inverter. You'd need the second triode for the feedback for a bistable, which is why I said I didn't know if it could be a latch (it's rather hard to latch without the other half). - Dave

On 2013 Mar 19, at 10:11 AM, Dave McGuire wrote: Yes, but Jules is right, there are a LOT of passives, esp. all those diodes. The photo is so blurry it's difficult to be sure about much, but it does look like 4 duo-triodes; on the side that can be seen half of each duo-triode appears to have 82-ohm cathode resistors, 4 grids each fed with two diodes and a 220K resistor through a 330-ohm parasitic-osc. suppression resistor. It's not what I would call typical flip-flop configuration, although it could conceivably still be 4 FFs with perhaps additional trigger/ SR gating. With all those diodes and from what can be seen though, it looks more like diode gates with tube buffers, i.e. multi-input logic gates. I kind of suspect a wired-gate config also, with two plates sharing a load resistor, as there appear to be only four plate load resistors in total (8.2K 2W) (although there are other configs that could negate that suggestion), and the plate connections that can be seen look like they might jumper across to the other plate. Hard to say given what can be seen. It's 4 bits max though if it were storage. (I've been told) there were other fast-storage techniques besides FFs used with tubes, but I don't see the support components for such alternatives here.