Running the Gemini again has been a reminder for me about what an impressive piece of engineering it is... and also of how much it could be improved nowadays!
The last several years' worth of Geminoid development has been an experimental foray into oversimplification. It was technically possible to build a universal constructor with only one construction arm, so I ended up doing that instead of solving the annoying encoding and signal-crossing problems that come along with running a two-arm U.C.
However, it seems pretty obvious that a two-arm U.C. will be much more efficient, so that the extra circuitry will easily pay for itself. And thanks to recent developments like simsim314's "armless" U.C. design, there really isn't that much circuitry needed. I would argue that the following device is a complete programmable two-armed U.C.:
Code: Select all
x = 912, y = 855, rule = B3/S23
648b2o$648b2o134$325b2o$2o323b2o$2o344bo$344b3o11bo$343bo14b3o$343b2o
16bo14bo$360b2o12b3o$373bo$373b2o3$372b2o$353b2o17b2o$353b2o2$315b2o$
315b2o3$356b2o$336b2o19bo$336bobo15b3o$338bo15bo$338b2o19b2o$360bo$
357b3o$357bo6$350b2o$351bo$351bobo15b2o$352b2o15b2o12$370b2o$370bobo$
372bo$372b2o9$360b2o$360b2o$348b2o$347bobo$347bo$346b2o2$371b2o$350b2o
19bo$351bo17bobo$351bobo15b2o$352b2o4bo$357bobo$357bobo$358bo10b2o$
369bobo$371bo$371b2o$356b2o$357bo$354b3o68bo$354bo68bobo$424b2o4$434b
3o2$432bo5bo$432bo5bo$432bo5bo2$434b3o2$443bo$442b2o$442bobo43$505b2o$
505b2o11$491b2o$490bobo$490bo$489b2o6$510b2o$510bo$511b3o$513bo4$494b
2o$493bobo$493bo$492b2o4$522bo34bo$522b3o32b3o$525bo34bo$502b2o20b2o
33b2o$502b2o7b2o56b2o$511bo57bo$509bobo55bobo$509b2o4b2o44b2o4b2o$493b
2o20bo44bo2bo$494bo18bobo45b2o$494bobo16b2o34b2o$495b2o52b2o8$524b2o
32b2o3b2o$524b2o11b2o20bo3bo$537bo18b3o5b3o$501b2o35b3o15bo9bo$497b2o
2b2o37bo$496bobo$496bo23b2o$495b2o23bo$521b3o$523bo24$533b2o$533b2o11$
519b2o$518bobo$518bo$517b2o6$538b2o$538bo$539b3o$541bo4$522b2o$521bobo
$521bo$520b2o4$550bo34bo$550b3o32b3o$553bo34bo$530b2o20b2o33b2o$530b2o
7b2o56b2o$539bo57bo$537bobo55bobo$537b2o4b2o44b2o4b2o$521b2o20bo44bo2b
o$522bo18bobo45b2o$522bobo16b2o34b2o$523b2o52b2o8$552b2o32b2o3b2o$552b
2o11b2o20bo3bo$565bo18b3o5b3o$529b2o35b3o15bo9bo$525b2o2b2o37bo$524bob
o$524bo23b2o$523b2o23bo$549b3o$551bo59$528b2o$528b2o9$513b2o$513b2o10$
533b2o$533bo$534b3o$536bo11$545bo34bo$545b3o32b3o$548bo34bo$525b2o20b
2o33b2o$525b2o7b2o56b2o$534bo57bo$532bobo55bobo$532b2o4b2o44b2o4b2o$
516b2o20bo44bo2bo$517bo18bobo45b2o$517bobo16b2o34b2o$518b2o52b2o8$547b
2o32b2o3b2o$547b2o11b2o20bo3bo$560bo18b3o5b3o$524b2o35b3o15bo9bo$520b
2o2b2o37bo$519bobo$519bo23b2o$518b2o23bo$544b3o$546bo9$738b2o$737b2o$
739bo8$464bo$462b2o$463b2o4$456b3o2$454bo5bo$454bo5bo$454bo5bo2$456b3o
7$448b3o$450bo$449bo6$361b2o$361b2o9$346b2o$346b2o10$366b2o$366bo$367b
3o$369bo4$350b2o$349bobo$349bo$348b2o4$378bo34bo$378b3o32b3o$381bo34bo
$358b2o20b2o33b2o$358b2o7b2o56b2o$367bo57bo$365bobo55bobo$365b2o4b2o
44b2o4b2o$349b2o20bo44bo2bo$350bo18bobo45b2o$350bobo16b2o34b2o$351b2o
52b2o8$380b2o32b2o3b2o$380b2o11b2o20bo3bo$393bo18b3o5b3o$357b2o35b3o
15bo9bo$353b2o2b2o37bo$352bobo$352bo23b2o$351b2o23bo$377b3o$379bo4$
457b2o$457b2o7$910bo$909b2o$909bobo2$443b2o$442bobo$442bo$441b2o6$462b
2o$462bo$463b3o$465bo4$446b2o$445bobo$445bo$444b2o4$474bo34bo$474b3o
32b3o$477bo34bo$454b2o20b2o33b2o$454b2o7b2o56b2o$463bo57bo$461bobo55bo
bo$461b2o4b2o44b2o4b2o$445b2o20bo44bo2bo$446bo18bobo45b2o$446bobo16b2o
34b2o$447b2o52b2o8$476b2o32b2o3b2o$476b2o11b2o20bo3bo$489bo18b3o5b3o$
453b2o35b3o15bo9bo$449b2o2b2o37bo$448bobo$448bo23b2o$447b2o23bo$473b3o
301b2o$475bo300b2o$778bo130$662b2o$661b2o$663bo!
Code: Select all
x = 710, y = 838, rule = B3/S23
84b2o$84b2o175$233b2o$218bo15bo$216b3o15bobo$203bo11bo19b2o$203b3o9b2o
$206bo$193b2o10b2o$194bo61b2o$194bobo59b2o$180b2o13b2o$180b2o36b2o$
218b2o2$174b2o$174b2o$178b2o$178b2o2$228b2o$209b2o18bo$173b2o34bo16b3o
$173b2o35b3o13bo$212bo33b2o$246b2o9$180b2o$181bo$178b3o$178bo$193b2o$
193bobo$195bo$195b2o6$329b2o$185b2o142b2o$176b2o7b2o$177bo$177bobo$
178b2o3$196b2o$196bo$194bobo$194b2o$315b2o$314bobo$180b2o132bo$179bobo
131b2o$179bo$178b2o4$334b2o$334bo$193b2o140b3o$183b2o8bo143bo$184bo6b
3o$181b3o$181bo$318b2o$317bobo$317bo$316b2o3$187b2o$187b2o4b2o151bo34b
o$193b2o151b3o32b3o$349bo34bo$326b2o20b2o33b2o$326b2o7b2o56b2o$192b2o
141bo57bo$188b2o2b2o139bobo55bobo$187bobo143b2o4b2o44b2o4b2o$187bo12b
2o115b2o20bo44bo2bo$186b2o11bobo116bo18bobo45b2o$199bo118bobo16b2o34b
2o$198b2o119b2o52b2o5$200b2o$199bobo$199bo$198b2o148b2o32b2o3b2o$348b
2o11b2o20bo3bo$361bo18b3o5b3o$325b2o35b3o15bo9bo$263bo57b2o2b2o37bo$
263b3o54bobo$266bo53bo23b2o$208b2o55b2o52b2o23bo$208b2o7b2o56b2o68b3o$
217bo57bo71bo$215bobo55bobo$215b2o4b2o44b2o4b2o$199b2o20bo44bo2bo$200b
o18bobo45b2o$200bobo16b2o34b2o$201b2o52b2o8$230b2o32b2o3b2o$230b2o11b
2o20bo3bo$243bo18b3o5b3o$207b2o35b3o15bo9bo$203b2o2b2o37bo$202bobo$
202bo23b2o$201b2o23bo$227b3o$229bo57$215bo$215b3o$218bo$217b2o6b2o$
224bobo$225bo3$212b2o$212b2o6b2o$220b2o2$229b2o$229b2o2$214b2o$213bobo
$213bo$212b2o53$183b2o$183b2o9$198b2o106b2o$198b2o106b2o10$178b2o$179b
o112b2o$176b3o112bobo$176bo114bo$290b2o6$182b2o127b2o$182b2o4b2o121bo$
188b2o122b3o$314bo3$187b2o$183b2o2b2o106b2o$182bobo109bobo$182bo12b2o
97bo$181b2o11bobo96b2o$194bo$193b2o2$323bo34bo$323b3o32b3o$326bo34bo$
195b2o106b2o20b2o33b2o$194bobo106b2o7b2o56b2o$194bo117bo57bo$193b2o
115bobo55bobo$310b2o4b2o44b2o4b2o$294b2o20bo44bo2bo$295bo18bobo45b2o$
258bo36bobo16b2o34b2o$258b3o35b2o52b2o$261bo$203b2o55b2o$203b2o7b2o56b
2o$212bo57bo$210bobo55bobo$210b2o4b2o44b2o4b2o$194b2o20bo44bo2bo$195bo
18bobo45b2o61b2o32b2o3b2o$195bobo16b2o34b2o73b2o11b2o20bo3bo$196b2o52b
2o86bo18b3o5b3o$302b2o35b3o15bo9bo$298b2o2b2o37bo$297bobo$297bo23b2o$
296b2o23bo$322b3o160b2o$324bo160bobo$225b2o32b2o3b2o219bo$225b2o11b2o
20bo3bo$238bo18b3o5b3o$202b2o35b3o15bo9bo$198b2o2b2o37bo$197bobo$197bo
23b2o$196b2o23bo$222b3o$224bo3$640b2o$640bobo$640bo83$2o$2o100$579b2o$
579bobo$579bo109$580b2o$580bobo$580bo15$707b2o$707bobo$707bo!
We may want to go in the opposite direction, and build a 10hd U.C. that uses spark-coil Herschel transmitters and receivers, similar to the ones in the parallel HBK gun. [But we can't pack signals quite that close because we don't want to have to build 7x9 eaters.]
I've been stopped from investigating that so far by the continued lack of a really good signal splitter. Spartan Herschel fanout devices can be built, but they're just awkward enough to be discouraging to work with -- by the time you're done correcting for chirality problems and so on, it ends up seeming easier to stick with plain old gliders and live with the p497 or p575 repeat time.
There are unavoidable signal crossings in this design (about which more in a future post). One advantage of not reworking the circuitry to pack signals more tightly, is that more attenuated streams have a much lower risk of interfering with each other at these crossing points.
It's also worth thinking about whether a hybrid design with one armless U.C. and one 10hd U.C. would turn out to be more efficient. Or even a three-U.C. design, maybe two 10hd arms and a very wide armless shotgun between them. Lots of permutations to consider here in the early design stages...!